Features and advantages of automatic water meter test bench
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Many countries around the world are facing the current situation of water scarcity. With the intensification of the greenhouse effect and the improvement of urbanization, as well as the pollution of the water system caused by industrialization, the contradiction between residents' lives and agricultural water use has become increasingly prominent. With the advancement of the city's "one household, one meter" tap water renovation project, the demand for water meters has also shown a substantial increase. At the same time, disputes between users and water supply companies often occur, partly because some water meters cannot provide accurate measurement results due to measurement errors. Ensuring the measurement accuracy of the user's water meter has become a key link in solving these problems.
Water meter test bench has the following characteristics:
1. Compared with the traditional manual verification device, the operation is simple, the computer calculates the error in the whole process, and avoids human factors;
2. Improve the efficiency of meter inspection, it only takes 8-10 minutes to detect a batch of water meters by the fully automated water meter detection device;
3. Energy-saving, water-saving, power-saving, labor-saving; full automation, sharing network, saving auxiliary materials;
4. Strong data management function: the software can automatically complete the entire inspection process and draw the verification conclusion, save all water meter verification data, have complete functions such as verification record query, correction, statistics, and printing, and it can also realize multiple inspection device groups. Internet, to realize the management and query of water meter data, the so-called Internet + mode;
5. Novel structure: 304 stainless steel material, high-end appearance, enhance corporate image;
6. Convenient operation: the front end is equipped with a high-speed camera as collection device;
7. It can automatically monitor and record the pressure and temperature of the pipeline (also can be manually input);
8. Each valve is independently controlled and can be opened and closed separately;
9. Three flow point detections can be realized, namely Q3, Q2, and Q1.
Meet the requirements for quick calibration of DN15&#;DN50 caliber mechanical water meters and ultrasonic water meters etc.
If you want to know more about the technical parameters of the automatic water meter test bench and manual water meter test bench, please feel free to contact us.
The Large Meter Test Bench System developed by MARS Company employs the latest in design and process control technology, setting the worldwide standard for the large meter testing and management industry. This versatile system can be configured to meet the testing needs of virtually any large meter management organization.
MARS Test Bench Systems are designed to meet / exceed American Water Works Association (AWWA) recommendations, National Institute for Standards and Technology (NIST) Handbook 44 Specifications, ISO Specifications and other standards and requirements.
Overview of water meter test bench:
In order to meet the requirements of liquid flow meter verification, calibration, factory inspection, and the growing trend of new flow meter production, improve the meter inspection efficiency of users in the field of water meter production and measurement, and reduce labor costs, our company has designed and manufactured an active flow meter with water as the medium. Piston liquid flow standard device;
This standard device has many advantages such as stability and reliability, good repeatability, a high degree of automation, and easy operation. The unique design avoids the shortcomings of the start-stop effect or commutator effect of traditional liquid flow standard devices, greatly improving measurement uncertainty. The device also has the characteristics of self-contained, compact structure, high efficiency, and energy saving. There is no need to build a pool or special structural requirements for the building. It is very suitable for production testing and product development testing of small flow metering instruments. This calibration device has been exported to overseas markets and has been exported to the European Union, Australia, and other countries many times. It has cooperated with multiple scientific research projects in "industry, academia and research" and has been deeply involved in the market for many years and has rich experience.
Structural composition and details of water meter test bench:
This device consists of a water source system, a meter clamping pipeline, a flow regulating device, a standard system, a commutator device, an image acquisition system, and a software control system. Its basic working principle is to compare the intercepts of the piston cylinder within a certain time interval. The volume flow rate of the discharged fluid obtained by multiplying the area and the piston displacement is compared with the volume flow rate of the flow meter being tested.
1) Water source system
The water source system includes a water pump, a water tank, an automatic pressure device, and a vacuum device. The water pump is of the Southern Pump Industry brand, with a maximum flow rate of 8m³/h and a head of 100m. It is controlled by a Danfoss inverter, and the software can set different frequencies. The pipeline is equipped with a balloon-type pressure stabilizing tank, which stabilizes the pressure of large flow disturbances. For Q2 and Q1 flow, the piston water supply is used to ensure stable flow.
The water tank is made of 304 stainless steel with a volume of 500L. The bottom is equipped with a liquid level, temperature sensor, heating device and outer insulation device. It can monitor the liquid level and temperature in real-time. The water temperature control accuracy can reach ±1&#;; the maximum set pressure of the pressure device is 2.5MPa. , the pressure can be set by the software, and the pressure and pressure relief are controlled by the PLC; the vacuum device can extract all the bubbles in the wet water meter to facilitate direct-read image data recognition by the camera.
2) Clamp meter pipeline
The meter inspection pipeline consists of the clamping device of the meter being inspected, pipelines, switch valves, etc. The clamping device of the meter under inspection is also called a meter clamp. It can adjust the distance according to the length of the meter and can clamp the meters under inspection of various specifications. The meter clamping device of this equipment adopts an external cylinder-type clamping mechanism, which effectively prevents internal air leakage caused by damage to the sealing ring due to long use. The meter clamping device of this device uses three optical axes as positioning points, and the optical axes are installed To the stainless steel fixed plate used for wire cutting production, the coaxiality is good.
The front and rear straight pipe sections are made of POM material with a very small coefficient of thermal expansion and contraction, and the slider is processed in one step using a CNC machining center.
The device adopts a single-row reversible meter clamping mechanism driven by a servo motor. The flipping of the meter clamping mechanism is beneficial to the vacuuming effect of the wet water meter, eliminating air bubbles and water stains on the dial, and at the same time increasing the acquisition success rate of image recognition.
3) Flow regulating device
The device is equipped with three flow point pipelines and uses two electromagnetic flowmeters as flow indication devices. Below 250L/h, DN2.5 caliber electromagnetic display is used, and above 250L/h, DN25 electromagnetic display is used. It is equipped with three flow point pipelines, which are used to adjust Q3 respectively. \Q2\Q1 flow point.
During automatic detection of the device, the software automatically adjusts and detects the required flow points based on the flow range, pump frequency, valve opening, and other parameters set by the control parameters. Each flow point is equipped with a pneumatic ball valve to control which electromagnetic flowmeter to use. , when the software detects that the current flow rate does not match the set flow rate, the software automatically controls the water pump frequency or the opening of the pneumatic control valve to adjust the required flow rate.
When the detected flow rate is within the range of 500L-L, the device can be equipped with a Samson pneumatic regulating valve with a flow adjustment accuracy of <2%. When the detected flow rate is below 500L, a piston is used to automatically push out a stable flow rate.
4) Standard device
The standard device adopts a combination of piston and electronic scale. When the flow is &#;500L, the piston is used as the standard to provide flow. The high-speed counter collects the displacement pulse of the grating ruler to measure the standard volume. When the flow is >500L, the water pump provides the flow.
The electronic scales and electromagnetic flowmeters of the device adopt internationally renowned brands. The device uses METTLER TOLEDO's 120KG/E electronic scale as the standard instrument. Electronic scales of different brands and accuracy can be selected according to the size of the water meter tested. The electronic scale is independently installed on the outside of the main body of the equipment, which reduces the error caused by the vibration of the equipment to the electronic scale and facilitates the calibration of the electronic scale.
The basic working principle of the piston system is to compare the volume flow rate of the fluid discharged by the piston within a certain time interval with the volume flow rate of the flow meter being tested. The volume of fluid discharged by the piston is obtained by multiplying the cross-sectional area of the piston cylinder and the piston displacement; the piston is Driven by a 22L Panasonic servo motor, the top of the piston is equipped with a temperature sensor with Class A accuracy and a measuring range of 0-100°C and a Hangzhou Miko pressure sensor with an accuracy of 0.5%. It is used to measure water temperature and water pressure and compensate for the piston bore error.
The active piston liquid flow standard device is shown in the figure above and mainly consists of a frame, piston rod, piston cylinder, motor, ball screw, supporting optical axis, sensor, protective shell, etc.
The piston rod is in close contact with the piston cylinder through the Y-shaped sealing ring. The three together form a sealed cavity. The movement of the piston rod is realized by the servo motor, coupling, ball screw, supporting optical axis, etc. The piston rod and the ball screw are The rod is connected through a screw nut, and the movement direction is controlled by a servo motor and a ball screw. A water suction pneumatic valve and a drainage pneumatic valve are installed at the outlet of the piston cylinder. The water suction pneumatic valve is connected to the water tank, and the drainage pneumatic valve is connected to the meter inspection pipeline. There are Install high-precision temperature and pressure sensors and install limit protection switches.
The core parts of the active piston liquid flow standard device are the piston rod and piston cylinder. Under the condition of ensuring sealing, the product of the outer diameter volume of the piston rod and the horizontal movement distance of the piston rod is the standard cumulative flow rate given by the device. Therefore, the processing accuracy of the piston rod, the sealing between the piston rod and the piston cylinder, and the accurate detection of the piston stroke within the calibration time period are the core of the device design.
Active piston devices can be divided into two categories: piston type and plunger type according to their structural forms. The piston type is in close contact with the piston cylinder through a sealing device, and the inner diameter of the piston cylinder is used as the measurement standard. Therefore, the inner wall of the piston cylinder needs to be finished, and the roughness of the inner wall and the roundness of the cylinder also have strict requirements. However, due to the influence of the length and diameter of the cylinder, it is difficult to process the inner wall of the piston cylinder, and the machining accuracy is difficult to guarantee. The plunger type uses the outer diameter of the plunger as the measurement standard, so the machining accuracy of the plunger is required to be higher. Nowadays, the machine The level of processing can ensure very good roundness and surface tolerance for the outer diameter of the plunger. The plunger type has a simple structure and a relatively reliable seal. The sealing ring is installed at the entrance of the piston cylinder for easy replacement. The form of the piston liquid flow standard device designed by the device is a plunger piston standard device.
Why choose an automatic water meter test bench with a piston device?
1. Stable flow and high calibration accuracy
2. There is no start-stop effect, and a stable flow rate can be achieved in 1S.
3. The clamping table has high concentricity and no air bubbles.
4. Automatic meter inspection, one-click operation
5. Piston automatic calibration system
6. Safety protection measures
7. No temperature is generated, the water temperature is constant
5) Commutator device
The device uses a flip-plate commutator as the flow-switching device. The commutator uses a rotating cylinder, which has the advantages of small vibration and fast switching speed. The uncertainty of the commutator is better than 0.05%. The commutator has been installed tested and calibrated at the factory. Photoelectric sensor, the user can switch at any time through the switch. The software of this device has the uncertainty detection function of the commutator transit time method. The user can detect the uncertainty error of the commutator by himself through the software during use.
6) Image acquisition system
What are the advantages of image acquisition systems?
Advantage 1: The image collection range is wide and no special alignment is required. As long as the dial pointer is within the range of the collected images, it can be recognized.
Advantage 2: It can be verified twice. After the test is completed, the software will automatically save the initial value and final value photos. If you have any objection to the test results of a certain table, you can query and save the pictures for review.
Advantage 3: High collection accuracy, collection error is within 0.001L
Advantage 4: Easy to install. The camera uses a POE-powered Ethernet industrial camera. It only needs one network cable to connect to the switch and the switch network cable to the computer network port.
7) Software control system
7-1) Software control system - hardware part
The control system mainly consists of industrial computers, PLC control systems, servo motors, grating rulers, various temperature and pressure sensors, pneumatic ball valves, platform software, etc. Industrial computers have strong anti-interference properties, which can make the calibration process more stable and reliable; PLC and servo motors are from internationally renowned brands with high precision and reliability.
Sensor:
The main sensors include a temperature sensor and a pressure sensor, which are located at the outlet of the piston cylinder. They are used to measure the temperature and pressure of the liquid respectively, and then transmit the information to the PLC and software system in a timely manner.
Sensors are important components for collecting analog quantities such as temperature, pressure, humidity, etc. Their accuracy and performance will directly affect the accuracy of the device's measurement results. Therefore, it is necessary to comprehensively consider various factors and select the most cost-effective sensor product. In this device, the temperature measurement range of the temperature sensor is (0~100)ºC, and the accuracy level is not less than 0.1&#;; the pressure measurement range of the pressure sensor is (0~1.6)MPa, and the accuracy level is not less than 0.2% level.
Grating ruler:
The standard cumulative flow rate of the active piston liquid flow device is the product of the internal cross-sectional area of the piston and the piston displacement within the time period. Therefore, accurate measurement of the piston displacement is one of the key factors to reduce the uncertainty of the device. In order to improve the accuracy of displacement measurement, this device uses a grating ruler to measure the displacement of the piston. The output signal of the grating ruler is an AB orthogonal signal, which is improved by 4 times based on the original accuracy.
Servo motor:
The driving element of the servo system is a servo motor. The servo motor converts the voltage signal into torque and rotational speed to drive the control object. Changing the voltage signal can change the rotational speed and steering direction of the servo motor. Servo motors have the characteristics of large starting torque, wide operating range, no rotation, and high positioning accuracy. They are widely used in various automation control systems. Compared with stepper motors, servo motors have the following advantages:
1. Higher control accuracy;
2. It has good low-frequency characteristics and will not vibrate at low speeds;
3. It has different torque-frequency characteristics. It can output rated torque within its rated speed and constant power output above the rated speed;
4. It has strong speed overload and torque overload capabilities, and the maximum torque is 2~3 times the rated torque;
5. The servo drive system is a closed-loop control. The driver can directly sample the motor encoder feedback signal, and internally constitutes a position loop and a speed loop, making the control performance more reliable; the rotational inertia of the rotary body part of the shaft, kg·cm2
6. The AC servo system has good acceleration performance and can be used in control situations that require quick start and stop.
Reasonable selection of servo motors is the key to designing a motion control system. During design, all requirements must be fully considered in order to give full play to the performance of the servo motors.
Speed matching. The selection of a servo motor should first ensure that the stroke speed of the device does not exceed the rated speed of the motor. In order to make full use of the power of the servo motor, the stroke speed should be as close as possible to the rated speed of the motor.
Torque matching. The rated torque of the servo motor must be greater than the maximum torque of the load, but there is no need to leave too much margin because the maximum torque of the servo motor is generally 2 to 3 times its rated torque. The torque calculation formula of the device is:
tnma supply professional and honest service.
F&#;&#;axial load, N;
L&#;&#;screw lead, m;
η&#;&#;mechanical efficiency;
i&#;&#;transmission ratio
The moment of inertia of the load needs to match the inertia of the servo motor. The large moment of inertia leads to large mechanical constants of the system, reducing servo accuracy and response speed. Therefore, during mechanical design, the moment of inertia should be minimized without affecting the stiffness of the system.
Jd = J L + J S
&#;
JL&#;&#;The moment of inertia of the moving parts converted to the motor shaft, kg·cm2;
JS&#;&#;Moment of inertia of the rotary body parts converted to the motor shaft, kg·cm2
PLC control system
The PLC control system of this device adopts Siemens S7-200smart system, uses ladder diagram programming language, and mounts analog input and output modules to collect and control temperature and pressure signals.
7-2) Software control system - software part
The software of this device is written in VISUAL STUDIO C# and uses the Microsoft ACCESS database. The detection process can be written into the database, and users can modify the control process according to different permissions. The software has an automatic meter reading function, which can be added to the software according to the user agreement to realize the collection of water meters and automatic correction of errors. After the detection, the error data is automatically saved to the database, and users can query the error data at any time.
Parameter settings:
Used to modify control parameters. According to national calibration regulations, instruments need to detect multiple flow points during the flow detection process. The parameter setting screen can add instrument parameters of different specifications and models according to user needs. After the addition, the data is saved to the database for the next time. When using, directly select the added specifications and models to call the instrument parameters added at that time.
Automatic detection program:
After setting the control parameters, click Auto Detection to enter the automatic detection program. The program runs according to the calibration point set by the control parameters. Before automatically detecting the flow point, the program will perform vacuuming, air bubble removal, and pressure suppression procedures. If these are not required, To operate, just turn off the corresponding switch in the instrument parameters.
Alarm display:
On the right side of the detection screen is the status display area. The running status information displays the current running distance of the piston and displays parameters such as temperature and pressure so that the user can understand the piston's operation in real-time. The software is set with multiple alarm prompts, such as a piston limit switch alarm, high-temperature alarm, high-pressure alarm, low-air pressure alarm, etc. You can view the alarm information and alarm level on the touch screen human-computer interaction interface, and solve the fault according to the instructions. When communication is normal, the indicator light in the communication status bar displays green. When communication fails, the indicator light of the corresponding device displays red.
Data query management:
Data query currently includes traffic original record and traffic certificate record data query. Users can query the detected data according to different query conditions. Users can print the queried data in report form according to their needs.
Report management:
The software is equipped with an open user report system, and users can edit calibration certificates and calibration records according to their own needs. Just write specific characters in the position of the variable that needs to be inserted, and the software will automatically insert the variable value.
This automatic testing platform adopts fully automatic control, fully automatic detection, and intelligent data processing and statistics. It has high meter inspection efficiency. It is driven by a servo motor to reduce the disturbance to the liquid flow, effectively solve the interference of water mist and bubbles, and has high calibration accuracy. It has the following characteristics :
1. Compared with traditional manual calibration devices, the operation is simple, and the computer calculates errors throughout the process to avoid human factors;
2. Improve the efficiency of meter inspection. The original manual meter inspection device takes 30 to 40 minutes to inspect a batch of water meters, and the upgraded automatic water meter inspection device only takes 5 to 8 minutes to inspect a batch of water meters. The meter clamping pipeline adopts an external cylinder-type clamping mechanism, which effectively prevents internal air leakage caused by damage to the sealing ring due to long use. The spacing can be adjusted according to the length of the meter, and inspection meters of various specifications can be clamped;
3. Save energy, water, electricity, and labor; small size, space-saving, fully automated, shared network, saving auxiliary materials. The flow adjustment device can automatically adjust and detect the required flow points according to the flow range, pump frequency, valve opening, and other parameters set by the control parameters. Each flow point is equipped with a pneumatic ball valve to control which electromagnetic flowmeter to use. When the software detects that the current flow rate does not match the set flow rate, the software automatically controls the water pump frequency or the opening of the pneumatic control valve to adjust the required flow rate;
4. The data management function is strong. The software can automatically complete the entire inspection process and draw calibration conclusions. It can save all water meter calibration data and has perfect functions such as calibration record query, correction, statistics, and printing. The camera direct reading acquisition method uses a POE camera and only needs one network cable to connect to the switch, and the switch network cable to the computer network port. The image collection range is wide and does not require special alignment. As long as the dial pointer is within the range of the collected images, it can be recognized. It can be verified twice. After the test is completed, the software will automatically save the initial value and final value photos. If you have any objection to the test results of a certain table, you can query and save the pictures for review. The collection accuracy is high, the collection error is 0.001L, and it also supports M-BUS, RS485, and other communication interfaces;
5. The structure is novel, the appearance is high-end, the industrial design and aesthetics are integrated, and the hardware and software complement each other, which can make the calibration process more stable and reliable;
Bearing in mind "customer first, quality first", we work closely with potential customers to provide them with efficient and professional Gas Flow Meters,Gas Meter Test Bench,Piston Type Circulating Real Gas Flow Standard Device,Gas Flow Measurement Instruments,Gas Meter Calibration,Sonic Nozzle Gas Meter Test Bench,Bell-Prover Gas Meter Test Bench,Gravimetric Water Meter Test Bench,Calibration Of Water Meters services
Cutting tool nomenclatures aren&#;t as cryptic as they look. Those code letters and numbers can be deciphered to reveal a wealth of information about indexable inserts.
Tool users are exposed regularly to various indexable-insert nomenclature and identification codes. For people trying to find the right tool for their job, these identification systems can be a confusing assortment of letters and numbers. And with the increasing use of superabrasive (diamond, PCD, and PCBN) cutting tools, the tool nomenclatures have evolved still further. Polycrystalline cutting tools often have unique identifying codes that are supplier-dependent. These only add to the size and scope of an already extensive string of identification code letters and numbers.
Most of the world&#;s insert manufacturers use either the American National Standards Institute (ANSI) indexable-insert identification system or the International Organization of Standards (ISO) system. The ANSI system is confined mainly to the United States and is available as ANSI publication No. 212.4. Most of the rest of the world uses the ISO identification system, although it is used in the United States as well. Some European and Asian cutting tool suppliers use ISO codes in their U.S. sales efforts, and U.S. tool exporters often code their products in ISO standard for overseas sales and distribution. This global distribution of cutting tools makes it important to understand both systems. The ANSI and ISO codes are illustrated on pages 36 and 37, respectively.
ANSI System
The ANSI code system (Figure 1) has been generally adopted by the U.S. cutting tool industry for the quick and accurate identification of indexable inserts. This system has been widely used throughout the United States for many years. The code system has evolved with the advancement of insert design and technology. But the code hasn&#;t evolved to the point where it encompasses all advancements. As shown in Figure 1, tool producers have added custom prefixes and suffixes to the standard code where needed.
The current ANSI code consists of up to 10 alphanumeric characters. Of these 10, the first seven are most commonly used. The first four of these seven characters are letters that identify the geometric characteristics of the cutting tool. The next three characters are numbers that describe the size of the cutting tool.
Specifically, the first character identifies the shape of the cutting tool. There are standard designations for simple shapes such as round (R), triangular (T), and square (S), as well as for more complex shapes such as diamonds (C, D, M, and V), octagons (O), pentagons (P), and parallelograms (A, B, E, and F). Although an extensive range of tool shapes is covered in the standard code, many manufacturers produce special shapes for which they adopt their own code identification. For example, one manufacturer may use the code G to designate a 45° parallelogram insert. This is not a universally accepted designation, however; another manufacturer may use G to signify an uneven hexagon with three flat sides and three sides ground in an arc. These special codes can sometimes cause confusion, but a code system that covers all possibilities is impractical. There are simply too many potential insert geometries.
T _ _ _ - _ _ _ - _ - _ _
The second character identifies the clearance angle of the cutting tool, which is the angle formed between the top of the tool and the flank surface. The angle specified is the angular difference from 90°. For example, the code letter N represents a 90° relationship between top and flank, or 0° clearance. This is commonly called a negative-clearance-angle cutting tool. Another popular tool has the code letter P. This represents a positive clearance angle of 11°. The most common clearance angles range from 0° (N) to 30° (G).
T N _ _ - _ _ _ - _ - _ _
The third character identifies the combination of tolerance ranges under which the cutting tool is manufactured. Tool users frequently will see the letter G in this position. This represents a tolerance of 0.001" on the tool&#;s inscribed circle (IC) dimension, 0.001" on the tip-radius altitude, and 0.005" on the tool thickness. The M tolerance code is also very popular for nonground, roughing-style tools. This code represents a tolerance of 0.002" to 0.010" on the tool&#;s IC and 0.005" on the tool thickness. The tolerance chart in Figure 1 describes a range of indexable-insert tolerances.
T N M _ - _ _ _ - _ - _ _
The fourth character describes the physical characteristics of the cutting tool&#;s mounting system and cutting-surface configuration. For instance, a flat-top, clamp-type cutting tool would have the code N. If that same flat-top cutting tool had a center hole for screw mounting, it would have the code A. If its center hole was countersunk on one side, it would have the code B. If the hole had an additional countersink on the opposite side, the insert would have the code C.
A different letter will be used in the fourth position if the insert has a clamp-on or molded-in chipbreaker. For example, if an N-type tool had a chip groove on one top surface, it would be called an R-style insert. If it had chip grooves on top and bottom, it would be an F-style tool. Add a hole, and it would be an M-type (one-sided) or G-type (two-sided) tool.
The fourth character describes many tool features. Currently, there are more than 17 different tool configurations described in the standards. And if this is not enough for the tool producer, there is the X designation for special designs. With all these possibilities, it is curious to note that this character is often omitted when describing commonly known turning inserts or when describing milling inserts.
T N M G - _ _ _ - _ - _ _
At this point, the code system changes from letters to numbers. The next three characters describe the physical size of the cutting tool.
The first of the numbers, or the fifth character in the code system, represents the insert&#;s IC in 1/8" increments. For example, a 1/4" IC insert is described by the number 2, representing 2/8". It follows that a 1/2" IC insert is represented by the number 4 and a 1" IC insert is represented by the number 8. The exception to this rule applies to small inserts with IC dimensions under 1/4". For small tools, the number in this place represents the IC dimension in 1/32" increments. The number 2 represents 2/32" or 1/16". It follows that 3 would describe 3/32" and so on, up to a 1/4" IC tool.
T N M G - 4 _ _ - _ - _ _
The sixth character represents the thickness of the cutting tool. Again, there is a split between large and small inserts. For inserts with IC dimensions of 1/4" and greater, this number describes the thickness in 1/16" increments. For small tools with IC dimensions less than 1/4", this number represents the thickness in 1/32" increments. A popular triangular small tool has a thickness of 3/32", which would be represented by the number 3 in the sixth place.
T N M G - 4 3 _ - _ - _ _
The seventh character can be a number or a letter. Numbers are used for tools with corner radii, which are normally inserts used in turning operations. The number describes the size of the corner radius in 1/64" increments. For example, a 1/32" radius is represented by the number 2, a 3/64" radius by the number 3.
T N M G - 4 3 2 - _ - _ _
Milling tools differ from turning tools in that they use a letter in the seventh place to describe the design of corner chamfers on the tool. Like the fourth place, this can be a very confusing part of the insert code. The seventh character describes the angle of the corner chamfers, relative to the insert side. The insert hand, left or right, is also a factor in the code letter used, as well as the presence of one or two chamfers per corner. For example, the letter E represents a 15° chamfer on a right-hand tool. The same tool in left-hand configuration would have the letter H in the seventh place. If the tool had two 15° chamfers, the code letter would be L. Because there are so many possible combinations, it&#;s best to reference a tool supplier&#;s identification guide when specifying a tool on an order using this character.
S N K _ - 4 3 E - _ - _ _
The eighth character also can be a letter or a number. When describing a nonmilling insert, which will be identified with a number in the seventh place, the eighth character is a letter. This character describes additional characteristics of the tools. An A, B, or C specifies honed edges, an N indicates negative lands, and a J identifies polished insert-rake surfaces.
T N M G - 4 3 2 - C - _ _
Milling insert tools, which have a letter in the seventh place in their identifying code, use a number in the eighth place. This number represents a milling insert&#;s wiper flat length and is measured in 1/32" increments. The wiper flat is most often a chamfer and ultimately produces the surface finish on the workpiece.
S N K _ - 4 3 E - 2 - _ _
For nonmilling inserts, the ninth and tenth places are most often used by tool producers to distinguish special features of their products. But for milling inserts, the ninth character indicates the direction of cut. This place is identified by the letter R for right or L for left. For both milling and turning tools, the tenth character is used at the cutting tool producer&#;s option.
S N K _ - 4 3 E - 2 - R _
ISO System
While the ISO cutting tool description system (Figure 2) uses metric units rather than inches, it has many of the features of the ANSI system. In particular, the first four characters are practically identical to the ANSI system. The first is the shape, the second is the clearance angle, the third is the tolerance range, and the fourth is the cutting-surface configuration and mounting system. A notable exception: In the ISO system, the fourth character is always used when describing milling inserts; in the ANSI system, it is often omitted.
T N M A - __ __ __ - __ - __
The big difference first shows itself in the fifth place. In the ISO system, the fifth place describes the cutting tool size by specifying the tool&#;s side length to the closest millimeter. This place therefore requires two digits for a proper description. Tool sizes designated under this system will vary significantly from tool sizes under the ANSI system, as the following example illustrates.
In the ANSI system, a 1/2" IC insert is represented by the number 4 (4/8"), regardless of the tool&#;s shape. But because a tool&#;s shape affects its side length, its shape will also affect its size description. Under the ISO system, a 1/2" IC insert will be represented by the number 12 (12mm) if it is a round, square, or 80° diamond insert; 22 if it is triangular; or 15 if it is a 55° diamond tool.
T N M A - 16 __ __ - __ - __
The sixth place in the code is also different from the ANSI system. Like the fifth place, it requires two digits and describes the tool thickness rounded off to the lowest whole millimeter. For example, a 1/8" thick cutting tool measures 3.18mm and has the code 03. A 3/16" thick cutting tool measures 4.76mm and has the code 04.
T N M A - 16 03 __ - __ - __
As in the ANSI code, the seventh character in the ISO code can be a number or a letter. Numbers are used for tools having corner radii, or turning tools, and letters are used for milling tools. For turning tools, the seventh place represents the nose radius size on the cutting tool. Once again, the ISO system uses a two-digit code in this place. The code represents the radius size in tenths of a millimeter. For example, a 1mm nose radius would have the code 10, whereas a 0.5mm radius would have the code 05.
T N M A - 16 03 08 - __ - __
For milling tools, the ISO system breaks the two letters in the seventh place into separate tool identifiers. The first letter identifies the angle of the wiper flat, or actual cutting edge, relative to the insert side, much like the ANSI code. The second letter describes the clearance angle of the wiper flat.
This tool geometry feature is not part of the ANSI system. In the example below, the letter A describes corner chamfers at 45° to the tool sides. The N following the A means the surface has a 0° or negative clearance angle.
T N L N - 12 04 AN - __ - __
As in the ANSI system, there are additional characters in the ISO system that can be employed but are often omitted. They are the cutting edge condition, the direction of feed, and the manufacturer&#;s optional area.
Superabrasive Inserts
Superabrasive cutting tools can be supplied in a wide variety of shapes and sizes. Three groups or categories can be established: full-topped indexable inserts, tipped indexable and single-edge cutting tools, and special-design tools such as rotating tools and saws.
Full-topped indexable inserts, tools with a superabrasive layer covering the entire top or top and bottom surfaces, can be identified adequately with the code systems just described. This is not so with tipped inserts, which have a substrate material that is formed into the familiar shapes described by ANSI or ISO codes. The actual cutting material, the superabrasive segment, is formed into an almost infinite variety of shapes and sizes and is inlaid into the base material.
On a tipped cutting tool, the size of the superabrasive insert, or segment, is a variable. Depending on the end user&#;s planned DOC, he might utilize a very small or very large segment.
At this time, each superabrasive cutting tool supplier has its own unique method of coding tipped inserts. Some are close to the ANSI or ISO standard, while others use codes that cannot be related to the insert standards. The tool suppliers that stay close to the ANSI standard often will add a suffix to the normally used seven-character identification code. This suffix is used to describe the superabrasive segment&#;s working edge length. In some instances, it also identifies the grade of the superabrasive material. For example, one supplier may use the suffixes 2F and 2G for diamond-tipped inserts and 4F and 4G for PCBN-tipped tools. Other suppliers may use two numbers to represent the length of the segment as measured down the insert side length. Still others may not list the side length at all, and thus only use the standard ANSI code as though the segment were not even on the tool.
A standard code system for tipped inserts is being reviewed by ANSI. The code combination is based on a suffix being added to the normal 10-character ANSI system. This suffix describes the details of the segment geometry. It is hoped that superabrasive tool producers will adopt the proposed suffix standard as they have adopted the existing code. It is certain that the indexable-insert code systems will continue to evolve. With new cutting tool geometries and materials being developed, the need to have a standardized description will remain. To stay current, users should periodically review the cutting tool identification information from their suppliers.
Figure 1: ANSI insert nomenclature. Provided by Valenite Inc.
Figure 2: ISO insert nomenclature. Provided by Valenite Inc.
About the Author
Richard Thalmann is general manager of superabrasive products for Wendt Grinding Corp., Rochester Hills, MI.
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