ASTM D412 is the standard test method for tensile properties of vulcanized rubber. A dumbbell or ring specimen is pulled to break and the result reports tensile strength, ultimate elongation, and modulus at 100, 200, and 300 percent elongation. CRC runs D412 in-house in an ISO/IEC 17025:2017 accredited lab, before and after heat or fluid aging.

ASTM D395 is the standard test method for compression set of rubber. Method B holds a specimen at a constant deflection, usually 25 percent, at temperature for a set time, then measures how much of the original thickness comes back. Method A holds a constant force instead. A lower percentage means better recovery, and recovery is what keeps a seal sealing for years.

ASTM D2240 is the durometer hardness test. A standardized indenter is pressed into the rubber and the resistance is read on the Shore A scale for elastomers, or Shore D for harder materials. Most rubber specifications carry a hardness with a plus or minus five point tolerance.

ASTM D2000 is the classification system prints use to call out a rubber. A line call-out names the type and class letters that set the heat and oil resistance, then the durometer and tensile grade, then suffix requirements such as compression set, low temperature, or fluid resistance. CRC reads D2000 call-outs and tests to the suffix requirements they carry.

Can CRC run these methods on my part rather than a test slab?

Yes for many of them. Hardness, adhesion, and fluid immersion can be run on finished parts, while tensile and compression set need standard specimens, which we can mold from the same batch as your part. Send the part with its service history through the sample submission page and the lab will scope it.

ASTM Rubber Test Methods | ISO 17025 Scope

Common ASTM methods we run, alongside hyperelastic characterization for FE models, compression modulus, and creep studies.

ASTM D2000General material call-out

ASTM D412Tensile & elongation

ASTM D2240Hardness / durometer

ASTM D4060Taber abrasion

ASTM D573Heat aging (air oven)

ASTM D429Adhesion strength

ASTM D624Tear strength

ASTM D395BCompression set

ASTM D1149Ozone resistance

ASTM D471Fluid resistance

ASTM D5992Dynamic shear

ASTM D6204/6601Cure & dynamic moduli

ASTM D1894Coefficient of friction

ASTM D453Aging properties

ASTM F3240Hydrophilic gasket swell

Method in depth: ASTM D429, rubber-to-metal bond testing — Methods A and B, and why the failure mode matters more than the load.

Standard Test Methods