The Basics of the NBS Abrasion Test

What Is the NBS Abrasion Test?

The NBS abrasion test — developed by the National Bureau of Standards (now NIST) — is a standardised method for evaluating the abrasion resistance of leather, rubber, and flexible polymeric materials. The test measures the volume loss of a specimen when rubbed against a standardised abrasive surface under defined load and conditions. Results are expressed as the NBS abrasion index — a relative wear resistance value compared to a reference material — making it a comparative rather than absolute measurement.

The NBS abrasion test is primarily referenced in footwear, leather goods, and rubber product testing and is governed by ASTM D1630, which defines the test procedure for rubber and rubber-like materials used in shoe soles and flooring applications.

Principle of the NBS Abrasion Test

A cylindrical test specimen is pressed against a rotating abrasive drum (typically covered with standardised abrasive paper) under a defined normal load. As the drum rotates, the specimen traverses the abrasive surface in a reciprocating pattern, wearing the specimen uniformly across its face. After a defined number of drum rotations (typically 1000–4000 cycles), the specimen is weighed, and the volume loss is calculated from the mass loss and measured specimen density.

The NBS abrasion index is calculated by comparing the volume loss of the test specimen to that of a reference rubber standard tested under identical conditions:

NBS Index = (Volume loss of reference / Volume loss of specimen) × 100

A higher NBS index indicates better abrasion resistance. A value of 100 indicates performance equal to the reference standard.

Why the NBS Abrasion Test Is Used

The NBS test is specifically designed for materials that experience sliding abrasion against rough surfaces — the primary wear mechanism in shoe soles, floor coverings, and conveyor belt covers. Unlike the Taber abrasion test (which uses abrasive wheels), the NBS test uses a flat abrasive surface that produces wear patterns more representative of the rubbing contact experienced by footwear and floor covering materials in service.

By normalising results against a reference standard, the NBS index accounts for day-to-day variations in abrasive paper condition, humidity, and temperature, providing more reproducible and comparable results than absolute volume loss measurements.

Factors Affecting NBS Abrasion Results

Material hardness, crosslink density, filler type and loading (particularly carbon black grade and loading in rubber compounds), polymer type, and surface finish all influence NBS abrasion resistance. Carbon black-reinforced natural rubber and styrene-butadiene rubber (SBR) typically achieve high NBS indices. Thermoplastic polyurethane (TPU) and thermoplastic rubber (TPR) compounds used in premium footwear outsoles also exhibit high NBS indices, reflecting their superior wear resistance for demanding applications.

Comparison with Other Abrasion Tests

Each test simulates a different wear mechanism and produces results relevant to its target application — direct comparison between methods is not valid.

Industrial Applications

In the footwear industry, NBS abrasion testing per ASTM D1630 is a standard qualification test for outsole rubber compounds. Branded footwear OEMs specify minimum NBS indices for performance and outdoor footwear categories. In the flooring industry, rubber floor tiles and athletic track surfaces are tested for wear resistance using NBS or equivalent methods. In industrial rubber products, conveyor belt covers, and rubber liners for mining equipment are evaluated by DIN abrasion (ISO 4649), but the NBS method is referenced for comparison purposes.

Conclusion

The NBS Abrasion Test is a widely recognised method for evaluating the abrasion resistance of rubber, leather, and flexible polymeric materials, particularly those used in footwear soles, flooring, and industrial rubber products. By measuring the material’s wear relative to a standard reference, the test provides a reliable comparative abrasion index that helps manufacturers assess durability and product performance.

Because the test closely simulates sliding contact against rough surfaces, it is especially valuable for applications where long-term wear resistance is critical. Materials with a higher NBS abrasion index demonstrate superior resistance to surface loss, making this test an essential quality control and product development tool in industries focused on durability and service life.

Why Choose Infinita Lab for NBS Abrasion Testing?

Infinita Lab provides NBS abrasion testing per ASTM D1630 for rubber, leather, and flexible polymer materials through our nationwide accredited materials testing laboratory network. Our rubber testing specialists deliver accurate, reproducible wear resistance characterisation with fast turnaround.

Looking for a trusted partner to achieve your research goals? Schedule a meeting with us, send us a request, or call us at (888) 878-3090 to learn more about our services and how we can support you.

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