ASTM is an international standards organization based in the United States. It publishes technical standard agreements for various materials, products, systems, and more. One of the widely used standards in the industry is ASTM E8/E8M.
ASTM E8/E8M Test Standard
Description
ASTM E8/E8M is an international test standard designed for tensile testing of metallic and steel materials at room temperature (10°C to 38°C or 50 to 100°F). Industries such as automotive, metal fabrication, alloy production, and construction commonly use this standard. ASTM standards are widely accepted by corporate and governmental bodies, including industries in Malaysia, where the government has adopted this standard.
This test measures the strength and ductility of metal, steel, alloys, and other materials under uniaxial tensile stress. The results help compare materials, support alloy development, ensure quality control, and assist in design considerations. ASTM E8 is used by those following imperial units, while ASTM E8M is for metric unit users. Tensile strength tests are conducted using a Universal Testing Machine (UTM), also known as a tensile testing machine.
The ASTM E8/E8M test typically measures:
- Yield Strength
- Yield Point Elongation
- Tensile Strength
- Reduction of Area
Specimens
The most common specimen types are rectangular and round. Flat specimens use flat grips, while round specimens require curved grips. Various types of specimens include:
- Round specimen
- Threaded round specimen
- Flat dogbone specimen
- Wire specimen
- Steel rod specimen
Grips
Mechanical grips are designed to self-tighten as the test progresses, providing secure clamping. Wedge grips are commonly used for metallic materials, as they increase gripping pressure during testing.
- Mechanical wedge grip
- Tensile wedge grip
- Jaw tension clamp
Extensometers
A high-accuracy extensometer is required to measure deformation in metallic materials. It determines properties such as modulus, yield, and elongation. A slightly lower-accuracy device is used for high-strain values.
- Electronic extensometer
Type of UTM Machine
For ASTM E8/E8M testing, a 50kN-100kN UTM machine is recommended, depending on material strength. A dual-column floor-type machine is preferred.
VEW 2302 Series
The VEW 2302 Computer Servo Type Universal Testing Machine integrates electronic technology with mechanical transmission. It offers precise load speed control, high sensitivity, and a broad force measurement range. It supports constant-velocity loading and displacement testing, making it ideal for quality control in production lines.
Main Functions:
- Tensile, compression, bending, shear, peel, tear, and two-point extension tests
- Suitable for materials like rubber, plastic, wire, optical fiber, leather, composites, waterproof membranes, metals, and alloys
Test Procedure
- Prepare specimens according to the method guidelines.
- Place the specimen into the grips.
- Clamp the specimen at the top grip first, then secure the bottom grip.
- Attach the extensometer to the specimen.
- Zero all machine settings before starting the test.
- Click the start button to begin testing.
- End the test after the specimen breaks (ruptures).
Different grip styles are available across various UTM brands, but the fundamental testing concept remains the same.