Information on the most widely used ASTM standards within the materials testing industry
ASTM D412, ISO 37, ISO 527
An eccentric roller grip is a self‑tightening tensile clamping device that uses an off‑center (eccentric) cam roller to generate increasing clamping force as tensile load rises. It is widely used for soft, thin, high‑elongation materials that tend to slip in standard vise grips. Suitable for test standard ASTM D412, ISO 37, ISO 527.
1, Key components:
Eccentric cam roller: Off‑center shaft, serrated/pyramid/grooved surface for friction;
Grip body: Aluminum/stainless steel housing with lever‑operated opening;
Spring‑loaded mechanism: Pre‑loads roller for initial clamping.
General introduction
An eccentric roller grip is a self‑tightening tensile clamping device that uses an off‑center (eccentric) cam roller to generate increasing clamping force as tensile load rises. It is widely used for soft, thin, high‑elongation materials that tend to slip in standard vise grips. Suitable for test standard ASTM D412, ISO 37, ISO 527.
Core Structure & Working Principle:
1), Key components:
Eccentric cam roller: Off‑center shaft, serrated/pyramid/grooved surface for friction;
Grip body: Aluminum/stainless steel housing with lever‑operated opening;
Spring‑loaded mechanism: Pre‑loads roller for initial clamping.
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2), Working Principle
Loading: Open grip via lever; insert flat specimen between roller and backstop.
Pre‑clamping: Spring pressure holds specimen lightly before load application.
Self‑tightening: As tensile load increases, the eccentric roller rotates, wedging tighter against the specimen—clamping force rises with test load.
Anti‑slip: Prevents slippage even as specimen thins during elongation.
Key Features
Shape: Flat sheets, dumbbell (dogbone) specimens, thin films
Thickness: Typically ≤7 mm; best for 0.1–3 mm
Width: Matches grip width (25–100 mm)
Not suitable: Small specimens (gauge length <10 mm), rigid metals, thick rigid plastics
Rubber & elastomers: Tires, seals, gaskets, O‑rings, flexible tubing
Plastics: Thin films, flexible sheets, packaging materials
Textiles & nonwovens: Fabrics, belts, webbings (low‑load)
Adhesives & coatings: Thin bonded layers
Wire & cable: Insulation, thin conductors
Self‑tightening: No slippage during high elongation
Fast loading: Single lever operation; high throughput
Gentle clamping: Reduces specimen damage at grip faces
Consistent results: Uniform clamping force across specimen width
Alignment: Upper grip often balanced to minimize non‑axial forces
| Standard | Material | Purpose |
|---|---|---|
| ASTM D412 | Vulcanized rubber, thermoplastic elastomers | Tensile properties, elongation, tear resistance |
| ASTM D624 | Rubber | Tear strength testing |
| ASTM D882 | Thin plastic films | Tensile properties of thin sheets |
| ISO 283 | Rubber, elastomers | Tensile stress‑strain testing |
| ISO 527‑2 | Plastics (thin films/sheets) | Tensile testing of flexible polymers |
| GB/T 528 | Chinese rubber standard | Tensile properties (equivalent to ASTM D412) |
Main specification:
Scope of delivery: 1 pair of grips
Material: Steel with Pyramid (serrated) face, 40 mm Diameter
Tensile force: 2 kN/5KN/10KN
Max sample width: 50 mm, max sample thickness: 0 - 7 mm
Connection: 30mm diameter, pin M12.
Weight: 2.5 kg each grip
Standard
ASTM D412 test methods cover procedures used to evaluate the tensile (tension) properties of vulcanized thermoset rubbers and thermoplastic elastomers. These methods are not applicable to ebonite and similar hard, low elongation materials.
The methods appear as follows:
Test Method A—Dumbbell and Straight Section Specimens
Test Method B—Cut Ring Specimens
ISO 37 and ASTM D412 are both widely recognized tensile test methods designed to evaluate the stress-strain characteristics of various rubber materials, including natural rubber, synthetic rubber, silicone rubber, and thermoplastic elastomers (TPEs). While both standards aim to determine the tensile properties of rubber and elastomers, they differ in their specific methodologies and applications.
ASTM D882: Standard Test Method for Tensile Properties of Thin Plastic Sheeting
ASTM D882 test methods is used to measure tensile properties including ultimate tensile strength, yield strength, elongation, tensile energy to break and tensile modulus of elasticity of thin plastic sheeting and films. The samples are cut in strips that minimally have to be eight times longer than wide. No dumbbell shape is cut for materials of that thickness. Cut samples need to be free of nicks and other cutting defects since they will have an important impact on the test results variation. The samples are tested in specific conditions of pre-treatment, sample orientation, temperature, humidity, and rate of pulling. ASTM D882 can be used for testing materials thinner than 1mm in thickness.
ISO 527-1 Plastics — Determination of tensile properties Part 1: General principles
ISO 527-2 Plastics -- tensile properties -- Part 2: moulding and extrusion
ISO 527-1 covers the test procedures for determining tensile properties of plastics and plastic composites. Tensile properties of plastics that are determined through the practices of ISO 527-1 include tensile strength, tensile modulus and other properties related to stress strain characteristics of plastic materials.
ISO 527-2 specifies the test conditions for determining the tensile properties of moulding and extrusion plastics, based upon the general principles given in ISO 527-1. The methods described in ISO 527-2 are selectively suitable for use with the following range of materials: rigid and semi-rigid thermoplastics moulding, extrusion and cast materials, including compounds filled and reinforced by, for example, short fibres, small rods, plates or granules but excluding textile fibres (see ISO 527-4 and ISO 527-5).
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