Rockwell Hardness Calibration Test Blocks

Make sure your hardness testers are accurately calibrated. Blocks are marked with their corresponding Rockwell hardness and a serial number.
All blocks come with a calibration certificate traceable to NIST that states they've passed a test for accuracy.
Benchtop Rockwell Hardness Testers

Bring material right to your bench to measure its hardness. These testers use a carbide indenter to take accurate Rockwell hardness readings every time. They come with a calibration certificate traceable to NIST that states they’ve passed a test for accuracy. With a durable metal body, these testers stand up to many environments, from heat treat facilities to workshops to inspection labs. They show readings on a dial—no need to hook them up to a power source.
These testers come with indenters for different scales, three anvils, four test blocks, and a case to store accessories. Use the included cover to shield them from dust when they’re not in use.
Throat | Ball Indenter | ||||||||||||||
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For Rockwell Hardness Scale | Hardness Measuring Range | Measuring Increments | Accuracy | Ht. | Wd. | Dp. | Ht. | Dp. | Dial Dia. | Material | Dia. | Includes | Specifications Met | Each | |
For Use On Aluminum, Brass, Bronze, Copper, Iron, Alloy Steel, Low-Carbon Steel, Steel, Titanium | |||||||||||||||
A, B, C, D, F, G | 20-100 | 1 | ±1 | 30" | 8 1/2" | 20" | 6 5/8" | 6 1/2" | 4" | Carbide | 1/16" | C-Scale Diamond Indenter, Ball Indenter, Three Anvils (Two Flat, One V), Four Test Blocks, Storage Case | ASTM E18 | 0000000 | 000000000 |
Durometer Hardness Testers


Measure the hardness of flat materials, such as plastic, rubber, and laminate. For more information about durometer scales, please see the bottom of About Rubber.
Style 3 testers come with a calibration certificate traceable to NIST that states they've passed a test for accuracy.
Mount these testers to an optional operating stand (sold separately) to make sure they’re parallel to your sample for accurate readings and repeatability.
Testers | Operating Stands | |||||||||||
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For Durometer Hardness Scale | Hardness Measuring Range | Measuring Increments | Accuracy | Ht. | Wd. | Dp. | Min. Material Thick. | Specifications Met | Each | Each | ||
For Use On Plastic, Rubber, Laminate | ||||||||||||
Style 3 | ||||||||||||
A | 0-100 | 1 | ±1 | 6 1/8" | 2 1/4" | 1" | 1/4" | ASTM D2240 | 00000000 | 0000000 | 00000000 | 000000000 |
D | 0-100 | 1 | ±1 | 6 1/8" | 2 1/4" | 1" | 1/4" | ASTM D2240 | 00000000 | 000000 | 00000000 | 00000000 |
O | 0-100 | 1 | ±1 | 6 1/8" | 2 1/4" | 1" | 1/4" | ASTM D2240 | 00000000 | 000000 | 00000000 | 00000000 |
OO | 0-100 | 1 | ±2 | 6 1/8" | 2 1/4" | 1" | 1/4" | ASTM D2240 | 00000000 | 000000 | 00000000 | 00000000 |
Digital Durometer Hardness Testers


Measure the hardness of flat materials with a digital display. For more information about durometer scales, please see the bottom of About Rubber.
These testers come with a calibration certificate traceable to NIST that states they’ve passed a test for accuracy. A maximum-reading indicator holds the highest reading until reset. Use the USB/RS-232 port for direct connection to your PC.
Testers for Shore M durometers take accurate readings on materials as thin as 0.05". Use them to take measurements of areas that are too small for durometer readings with a Shore A scale tester.
Mount the tester to an operating stand (sold separately) to ensure it is perfectly parallel to the sample. This reduces error and gives accurate, repeatable readings.
Testers | Operating Stands | ||||||||||||
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For Durometer Hardness Scale | Hardness Measuring Range | Measuring Increments | Accuracy | Ht. | Wd. | Dp. | Min. Material Thick. | Batteries Included | Features | Each | Each | ||
For Use On Plastic, Rubber, Laminate | |||||||||||||
A | 0-100 | 0.1 | ±1 | 6 1/8" | 2 1/2" | 1 5/8" | 1/4" | Yes | Maximum-Reading Indicator, Tolerance-Setting High/Low Buttons, USB and RS-232 Connectivity | 00000000 | 000000000 | 00000000 | 000000000 |
D | 0-100 | 0.1 | ±1 | 6 1/8" | 2 1/2" | 1 5/8" | 1/4" | Yes | Maximum-Reading Indicator, Tolerance-Setting High/Low Buttons, USB and RS-232 Connectivity | 00000000 | 00000000 | 00000000 | 00000000 |
M | 0-100 | 0.1 | ±4 | 6 1/8" | 2 1/2" | 1 5/8" | 1/16" | Yes | Maximum-Reading Indicator, Tolerance-Setting High/Low Buttons, USB and RS-232 Connectivity | 000000000 | 00000000 | 0000000 | 00000000 |
For Use On Rubber, Foam | |||||||||||||
OO | 0-100 | 0.1 | ±2 | 6 1/8" | 2 1/2" | 1 5/8" | 1/4" | Yes | Maximum-Reading Indicator, Tolerance-Setting High/Low Buttons, USB and RS-232 Connectivity | 000000000 | 00000000 | 00000000 | 00000000 |
For Use On Rubber | |||||||||||||
O | 0-100 | 0.1 | ±1 | 6 1/8" | 2 1/2" | 1 5/8" | 1/4" | Yes | Maximum-Reading Indicator, Tolerance-Setting High/Low Buttons, USB and RS-232 Connectivity | 000000000 | 00000000 | 00000000 | 00000000 |
Durometer Hardness Test Block Sets

Confirm your durometer hardness tester is taking accurate readings. Use your tester on these blocks to make sure the durometer readings match the block. The blocks come with a calibration certificate traceable to NIST to ensure their accuracy.
For Durometer Hardness Scale | Lg. | Wd. | Dp. | Includes | Container Type | Each | |
A | 2" | 2" | 1/4" | Seven 2" x 2" Test Blocks (Durometer 30A-90A) | Carrying Case | 0000000 | 0000000 |
D | 2" | 2" | 1/4" | Three 2" x 2" Test Blocks (Durometer 20D-80D) | Carrying Case | 0000000 | 000000 |
M | 2" | 2" | 1/4" | Seven 2" x 2" Test Blocks (Durometer 30M-90M) | Carrying Case | 0000000 | 000000 |
OO | 2" | 2" | 1/4" | Three 2" x 2" Test Blocks (Durometer 30OO-70OO) | Carrying Case | 0000000 | 000000 |
O-Ring Durometer Hardness Testers
Test the hardness of thin and irregularly shaped plastic, rubber, and laminate parts, such as O-rings. These testers can be used on products where the surface area is too small for accurate durometer readings with a standard Shore A tester, such as the rounded surface of O-rings. They include O-ring fixtures that hold five standard-sized O-rings in place during testing. These testers are also capable of measuring materials as thin as 0.05″, about the thickness of a credit card. On the display, they’ll show the highest reading until they’re reset. They include a calibration certificate traceable to NIST that states they’ve passed a test for accuracy.
Use the included test blocks to practice taking accurate measurements at the right pressure against your workpiece. Send your measurement data directly to your PC using the USB port.

For O-Ring Wd. | For Durometer Hardness Scale | Hardness Measuring Range | Measuring Increments | Accuracy | Min. Material Thick. | Max. Display Rotation Angle | Batteries Included | Features | Includes | Each | |
For Use On Plastic, Rubber, Laminate | |||||||||||
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1/16", 3/32", 1/8", 3/16", 1/4" | M | 0-100 | 0.1" | ±4 | 1/16" | 270° | Yes | Maximum-Reading Indicator, Tolerance-Setting High/Low Buttons, USB and RS-232 Connectivity | Digital Durometer Hardness Tester for M Hardness Scale, Seven 2" x 2" Test Blocks (Durometer M), Five O-Ring Fixtures, Operating Stand, Set Plug | 0000000 | 000000000 |
For Durometer Hardness Scale | Hardness Measuring Range | Measuring Increments | Accuracy | Ht. | Wd. | Dp. | Min. Material Thick. | Max. Display Rotation Angle | Batteries Included | Specifications Met | Features | Each | |
For Use On Plastic, Rubber, Laminate | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
M | 0-100 | 0.1 | ±4 | 6 1/8" | 2 1/2" | 1 5/8" | 1/16" | 270° | Yes | ASTM D2240 | Maximum-Reading Indicator, Tolerance-Setting High/Low Buttons, USB and RS-232 Connectivity | 000000000 | 000000000 |
For Durometer Hardness Scale | Hardness Measuring Range | Lg. | Wd. | Dp. | Includes | Container Type | Each | |
M | 30-90 | 2" | 2" | 1/4" | Seven 2" x 2" Test Blocks (Durometer 30M-90M) | Carrying Case | 0000000 | 0000000 |
Brinell Hardness Calibration Test Blocks

Check your hardness tester for accuracy against a block with a known hardness rating. Each block is tested according to ASTM E10, which checks the hardness at five locations along the block. They include a certificate that lists the block’s actual hardness, as well as each of the five measurements taken during the test. Blocks also include a NIST-traceable certificate that states they’ve passed a test for accuracy.
Each block is marked with their Brinell hardness rating and a serial number.
For technical drawings and 3-D models, click on a part number.