Polyurethane Wear Pads and Liners: Hardness Selection Guide (80A–95A)

When choosing polyurethane wear pads or liners, hardness is often one of the first specifications buyers compare. A harder material may provide better support and resist deformation under certain loads, while a softer grade may absorb impact and accommodate movement more effectively.

However, hardness alone does not determine service life. The correct grade depends on the load, contact surface, operating temperature, chemical exposure, and whether the component is sliding, compressing, or absorbing impact.

What Do 80A, 90A, and 95A Mean?

Shore A is a durometer scale used to measure the indentation hardness of elastomeric materials, including many polyurethane grades. A higher reading indicates greater resistance to indentation under the specified test conditions.

The following is a general selection guide, not a substitute for testing the actual polyurethane formulation.

80A: More flexible

An 80A grade may be worth evaluating where compliance and impact absorption are important. Depending on the formulation and component design, it may deform more under load than a harder grade.

90A: A middle option

A 90A grade can be a useful starting point when a component needs a balance between flexibility and support. Actual performance still depends on the polyurethane chemistry, load, contact conditions, and temperature.

95A: Firmer support

A 95A grade may be suitable where lower deformation and firmer support are required. It should not automatically be assumed to provide the longest service life in every abrasive or impact application.

Industrial suppliers offer polyurethane wear strips and pads in grades such as 80A, 90A, and 95A. These are available options, not universal standards for every wear liner.

How to Choose the Right Hardness

Identify the Main Failure Mode

If the pad deforms excessively, creeps under sustained load, or loses its shape, evaluate whether a harder grade or a different component design is needed.

If the part tears, cracks, or suffers impact damage, simply increasing hardness may not solve the problem. Toughness, thickness, geometry, and the actual impact conditions also matter.

Consider Sliding Abrasion

For a liner that continuously contacts moving material, evaluate the abrasive particles, contact pressure, sliding speed, and surface finish. Test candidate grades under conditions representative of the actual application where possible.

Check Temperature and Chemical Exposure

Polyurethane formulations differ in their resistance to heat, oils, water, cleaning chemicals, and other substances. Do not assume that two materials with the same Shore A hardness have the same chemical or temperature performance.

Confirm the Measurement Method

Hardness readings can be affected by test method, specimen thickness, surface condition, and the time allowed for the reading. Compare supplier data obtained using comparable test conditions.

What Information Should Be Included in an RFQ?

When requesting a replacement wear pad or liner, provide:

• Drawing or sample and all critical dimensions.
• Required hardness and the test standard, if specified.
• Operating temperature and chemical exposure.
• Type of contact: sliding, compression, or impact.
• Load conditions and the current failure mode.
• Any available service-life or inspection records.

If the correct grade is uncertain, request a comparison of candidate materials and consider a controlled trial. Record the operating conditions and failure mode so that the next selection is based on evidence rather than hardness alone.

The best polyurethane hardness is the one that fits the component’s actual working conditions—not simply the highest number on the specification sheet.