Mechanical Testing of Steel Products - Bolt Tension
Test Method Summary
ASTM A370 defines test methods and definitions for mechanical testing of steel products. Bolt Tensile testing of steel products per ASTM A370 is used to determine the proof load. The proof load is the maximum tensile force that can be applied to the bolt without causing plastic deformation.
The standard supports either the preferred length measurement method, during which the bolt is stressed with a specified tensile load for 10 seconds and then it is checked, if the bolt wasn’t plasticly deformed. Or the yield strength method, during which the bolt is stressed and the elongation of the bolt is measured. The tensile load or stress that produces 0.2% plastic deformation must be equal to or larger than the specified value in the product specification.
Please refer to the standard for more detailed information about the other test setups and for testing tubular and round wire products.
Solutions for ASTM A370 Bolt Tension typically include these types of components:
Load Frame Options
MTS offers electromechanical Criterion® and Exceed® universal test systems and dynamic servohydraulic Landmark® test systems that are ideal for performing accurate and repeatable monotonic bolt tensile testing per ASTM A370.
MTS Criterion universal testing systems are engineered to support the needs of advanced Research & Development. MTS Exceed universal testing systems are best suited for Quality Control testing by delivering the reliable performance needed to meet the uptime demands of high-volume production environments. MTS offers frame models that address the force requirements for testing various bolt sizes.
The MTS Criterion and the MTS Exceed universal testing machines range from tabletop to floor-standing electromechanical models with force ratings of up to 600 kN / 135 kip. Many of the models have dual-zone test spaces to reduce set-up times if you frequently change test requirements.
The MTS Landmark dynamic servohydraulic test system with its superior stiffness and alignment capabilities, is an ideal choice if additional fatigue and fracture testing capabilities are required. Systems are available in highly configurable floor-standing and tabletop models with force ratings from 5 kN / 1 kip to 500 kN / 110 kip.
As an alternative to a new load frame, you can replace outdated controls / hydraulics of existing MTS or another manufacturer’s electromechanical, servohydraulic or custom test systems, including: **Instron®, **Zwick®, **Tinius Olsen™, **SATEC®, **Baldwin® and more with an MTS ReNew™ Upgrade.
**Trademark owned by their respective owners, not affiliated with MTS Systems Corporation.
ASTM A370 refers to ASTM E8/E8M for the testing equipment requirements. ASTM E8/E8M requires that extensometers conform to ASTM E83. MTS offers a variety of extensometer types, ranging from clip-on, automatic to non-contacting optical and video extensometers, that meet or exceed requirements for calibration according to ASTM E83 Class B1 and ISO 9513 Class 0.5 standards. Factors like the specimen material, shape and dimension, the requirements for test efficiency and budget need to be considered when choosing the appropriate strain measurement solution.
For other options related to this standard, please download the application test method tech note on this page.