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Rex Durometer Testers

Q: Why does ASTM D2240 recommend omitting Durometer readings below 20 or above 90?

Per ASTM D2240 Section 9.3 , indentation readings below 20 or above 90 on any given Shore scale lose linearity at the extreme ends of spring travel. If your material tests above 90 on a Shore A Durometer, switch up to a Shore B or Shore D scale; if it reads below 20 on a Shore A Durometer, step down to a softer scale such as Shore O , Asker C , or Shore OO .

F.A.Q.

Why does ASTM D2240 recommend omitting Durometer readings below 20 or above 90?

Per ASTM D2240 Section 9.3, indentation readings below 20 or above 90 on any given Shore scale lose linearity at the extreme ends of spring travel. If your material tests above 90 on a Shore A Durometer, switch up to a Shore B or Shore D scale; if it reads below 20 on a Shore A Durometer, step down to a softer scale such as Shore O, Asker C, or Shore OO.

What is the minimum sample thickness required for standard Shore A and Shore D testing?

Standard Shore A and Shore D indenters require a minimum specimen thickness of 6 mm (0.24") so the hard surface of the test table does not influence the reading ("anvil effect"). While thinner layers can be stacked (up to 3 plies) if the surfaces are completely flat, the most accurate solution for specimens as thin as 0.050" (1.25 mm) or small O-rings is a Type M Durometer (Rex 1600-M or Rex DD-4-M) mounted in the Rex OS-3 Type M Test Stand.

What is the difference between a standard dial Durometer and a Max-Hand (Memory Pointer) model?

A standard dial gauge like the Rex 1600 has a single active pointer that shows live hardness as long as the presser foot is held against the specimen. The Rex 2000 Max-Hand Shore Durometer (which replaced the RX-1700) adds a second peak-hold pointer that locks at the maximum initial reading while the active pointer creeps downward, allowing the operator to record both peak hardness and material relaxation (creep) simultaneously.

What is the difference between a Durometer Test Block and a Durometer Verifier?

Color-coded rubber test blocks (included with most Durometers) allow operators to perform a quick daily functional check to confirm the indenter and spring "feel" are operating properly, but they should not be used to recalibrate a gauge. To formally verify and certify the spring load accuracy of Shore A and Shore D probes across 10 to 90 Durometer units in-house, use the electronic load-cell-based DeFelsko SHDVERIFY PosiTector SHD Verifier Kit.

Rex RX-1600-A120 Skateboard Wheel Durometer

$765.00

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Rex RX-1600-A120 Skateboard Wheel Durometer

Rex RX-1600-A120 Skateboard Wheel Durometer
Specially designed for the skate community
Manufacturer: Checkline
Warranty: One Year

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Rex 4000 Max Hand Durometer RX-4000

$1,518.00

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Rex 4000 Max Hand Durometer RX-4000

Available Scales: A, D
Rex 4000 Max Hand Durometer RX-4000
Holds Reading Until Reset

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Rex 1600 Dial Shore Durometer RX-1600

$528.00 - $913.00

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Rex 1600 Dial Shore Durometer RX-1600

Rex 1600 Dial Shore Durometer RX-1600
Available Scales: A, AO, B, CF, D, E, DO, M, O, OO, OOO, OOO-S (Asker, ISO, DIN & JIS Scales also available, inquire)
Conforms to ASTM D-2240
Includes NIST Calibration Certificate

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Rex 2000 Max-Hand Shore Durometer RX-2000

$693.00 - $754.00

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Rex 2000 Max-Hand Shore Durometer RX-2000

Rex 2000 Max-Hand Shore Durometer RX-2000
Available Types:
A, D, B, C, DO, E, and O
Conforms to ASTM D-2240
Includes NIST Calibration Certificate

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Rex DD-4 Precision Digital Shore Durometer RX-DD

$1,260.00 - $1,700.00

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Rex DD-4 Precision Digital Shore Durometer RX-DD

Rex DD-4 Precision Digital Shore Durometer RX-DD
Available Scales: A, AO, B, C, D, DO, E, M, O, OO, OOO (Asker, ISO, DIN & JIS Scales also available, inquire)
Conforms to ASTM D-2240
Includes NIST Calibration Certificate

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