ASTM A370 | Metals | Tension Testing, Bend Testing
ASTM A370 is a testing standard that covers the mechanical testing definitions and procedures of steel products such as wrought and cast steels, stainless steels, and related alloys. This standard covers tension, bend, hardness, and impact tests.
The various mechanical tests described in this specification can be used to determine the properties required in the product specifications. ADMET universal testing machines conform to the requirements of Practices E4 and can be used for A370 tension and bend testing. Hardness and impact tests will not be covered in detail in this post, as we do not offer machines for these tests. Prior to conducting ASTM A370, it is important to read the entire specification in the relevant ASTM publication.
ASTM A370 | Metals | Tension Testing, Bend Testing
Note that in general, the testing equipment and methods are given in ASTM E8. However, there are certain exceptions to ASTM E8 practices in the testing of steel, and these are covered in the methods below.
Procedure A: Tension Test
- Measure and record the specimen dimensions necessary to determine the cross sectional area at its smallest point. The original cross sectional area is used for all engineering stress calculations.
- Mark the gauge length with a center punch, scribe marks or draw with ink. The distance between the gauge marks after the specimen is broken is used to determine the percent elongation at break.
- Zero the testing machine without the specimen inserted in the grips. Install the specimen in the grips and attach a Class B1 axial extensometer to the specimen. Please note that the extensometer needs to be removed prior to specimen failure. ADMET software stops test and prompts the removal of the extensometer once the total strain data has been satisfactorily obtained.
- Start loading the sample. The speed of testing is generally specified in one of three manners: a) rate of movement of the crosshead of the testing machine when not under load; b) the rate of stressing of the specimen; or c) the rate of separation of the crossheads under load. Any convenient speed of testing may be used up to one half the specified yield point and down to 1/10 the specified maximum rates for determining yield strength and tensile strength.
- Run the test until specimen failure or fracture. Remove the broken sample from the machine and fit the fractured ends together. Measure the distance between the gauge marks to the nearest 0.05 millimeters.
- Ultimate Tensile Strength or Peak Stress
- Yield Strength by Offset or Extension Under Load Method
- Percent Elongation at Break (includes plastic deformations only)
- Reduction of Area
- Yield Point Elongation (YPE)
- Elongation at Fracture (includes elastic and plastic deformations)
Procedure B: Bend Test
- Test methods E190 and E290 should be consulted to perform bend testing per ASTM A370. Bend tests should be performed to test ductility but it cannot be considered as a quantitative means of predicting service performance in bending operations.
Calculations:
- Bend Strength
ASTM A370 | Metals | Tension Testing, Bend Testing
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- Metal testing on an eXpert 1600
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- Closeup of grips for steel testing
ASTM A370 | Metals | Tension Testing, Bend Testing
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