ASTM A746 Specification for Ductile Iron Gravity Sewer Pipe

When performing acceptance tensile tests on ductile iron (as specified in ASTM A746), a machined specimen must be tested. This specimen is called a shouldered specimen.

 This round specimen is sometimes referred to as a "dumbbell," "dog bone," or "button-end specimen" with the shouldered end used to grip the specimen during the test.

Modern ASTM A746 tests need to be run at specific stress rates under servo control and require extensometers to accurately calculate 0.2% offset yield and ultimate tensile strength.

Customers today require automated control and precise measurements to ensure their ductile iron pipe products are viable before they are buried in the ground. 

These contemporary demands make older testing techniques, such as manual calibration or drop beam observation, no longer appropriate.

We offer systems for tensile testing standard 0.505-inch diameter shouldered specimens, 0.750-inch diameter specimens, and smaller size specimens required in ASTM A746. 

Since the maximum load requirement for these sizes is approximately 30,000 lbf, we recommend using an Industrial Series 300LX load frame with open-end insertion tensile grips and brackets. 

These tensile grips are designed for testing ductile iron specimens and can be adapted to the test frame with our Universal Spherical Tensile Adapter (USTA). The USTA adapter provides the necessary specimen alignment.

The 300LX's single test space and double-acting actuator allow operators to easily mount specimens. Split-sleeve shoulder-end specimen holders allow for quick changes of test specimens. 

They also contain the end of the broken specimen during failure, providing additional safety for the operator. The USTA assembly enables the specimen to self-align during loading, easily meeting the 

alignment requirements of ASTM E8.

Materials Testing Software Provides the necessary control parameters and calculation algorithms to meet ASTM E8 and ASTM A746 test standards. In addition, it provides simple test setup and efficient test operation.