ASTM D429
Rubber-to-Metal 90° Peel Test Fixture
ASTM D429 90° Peel Fixture – Universal Grip Data Sheet (PDF)
ASTM D429 covers test methods for the static adhesion strength of rubber bonded to rigid materials, mostly metals. Makers of bonded rubber parts, anti-vibration mounts and tank linings, and bonding agent suppliers, use it to qualify bonds and processes. Universal Grip supplies a 90-degree stripping fixture for the D429 peel methods, with variants for other methods on request.
What ASTM D429 Measures
D429 measures the force needed to separate rubber from a rigid substrate and records how the bond fails. In the 90-degree stripping test, a rubber strip bonded to a metal plate is peeled away at a right angle to the bond line while force is recorded. Failure is described as a split between rubber, cement and metal, which tells you whether the rubber or the bond gave way. Other D429 methods pull apart, shear or cone-test bonded parts.
How the ASTM D429 Test Works
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Prepare a rubber strip bonded to a metal plate with an unbonded tab at one end.
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Clamp the metal plate rigidly in the fixture so it cannot rotate or bend.
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Grip the rubber tab in the upper jaw at 90 degrees to the bond line.
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Strip the rubber at a constant rate while the fixture keeps the 90-degree angle.
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Record the stripping force and estimate the percentage of each failure type on the substrate.
Specimens and Setup
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Follow the D429 method your specification calls out; geometry differs by method.
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Prepare metal surfaces and apply primer or adhesive exactly as the production process does.
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Leave enough unbonded tab length to grip securely in the upper jaw.
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Inspect the separated surfaces after testing and classify the failure mode.
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Refer to the current edition of ASTM D429 for plate size, strip dimensions and rate.
Universal Grip ASTM D429 Fixture
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5 kN standard capacity; higher capacities on request
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Maintains a constant 90-degree peel angle between rubber tab and bonded substrate
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Rigid substrate clamp stops the metal strip from rotating or bending during peel
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Upper grip for the rubber tab with serrated or rubber-faced jaws
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Hardened steel body with corrosion-resistant finish; quick-change specimen loading
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Clevis pin or threaded adapter; optional variants for other D429 methods
Applications
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Rubber-to-metal bonded parts
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Bonding agent and primer evaluation
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Anti-vibration mounts and bushings
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Rubber tank and roll lining QA
Related Standards and Products
Tell us which D429 method you run, your substrate size and frame connection, and we will quote a fixture. Request a quote
ASTM D429 FAQ
Which ASTM D429 methods does this fixture cover?
It is built for 90-degree stripping of rubber from a single metal plate, as in Method B; Method E (tank lining) is also a 90-degree strip test. Methods A, C, D, F, G and H use pull-apart, conical or shear specimens and need different fixtures, available on request.
Why is a constant 90-degree angle important?
The measured force depends on peel angle. If the substrate rotates or the angle drifts, the force changes even though the bond is the same. The fixture clamps the plate rigidly and keeps the tab at right angles so results are repeatable.
How is failure mode reported?
After stripping, inspect the metal surface and estimate how much of the area failed in the rubber, at the rubber-adhesive interface, within the adhesive or at the metal. Rubber failure generally means the bond is stronger than the rubber itself.
How does D429 differ from D413?
D429 covers rubber bonded to rigid substrates, mostly metal. D413 covers rubber bonded to flexible substrates such as fabric plies in belting and hose. The specimens and fixtures are different, though both measure separation force.
Will it fit my test machine?
Yes. The fixture is supplied with a clevis pin or threaded adapter for your electromechanical universal testing machine. Tell us your frame and the D429 method when requesting a quote.