Polyurethane Durometer Information
What Is Polyurethane Durometer?
Durometer is a measure of hardness used for soft materials like rubber, plastic, and polyurethane. It quantifies a material’s resistance to deflection—similar in principle to the Rockwell scale used for metals, but designed specifically for soft, non-metallic materials. Because soft materials vary widely in hardness, multiple Shore scales exist to provide accurate readings across the full range. The Shore A scale is most commonly used for polyurethane parts due to its wide range. It spans from very soft and flexible materials (0–40A), to medium hardness (50–80A), and very hard, rigid materials (90–100A). Meridian Laboratory primarily operates within this range and commonly offers 40A, 55A, 70A, 80A, and 90A options—but can accommodate other durometers as needed. For harder plastics and polyurethanes, the Shore D scale is used. These materials are more rigid and less flexible than materials in the Shore A scale range. Meridian Laboratory offers molded polyurethane parts in Shore D values up to 75D, ideal for applications requiring exceptional stiffness, high load bearing, and wear resistance.How Do You Measure Durometer?
Durometer is measured using a specialized gauge equipped with a spring-loaded indenter that presses into the material’s surface. The resistance is translated into a hardness reading, either analog or digital, depending on the gauge type. Different Shore scales require specific indenter shapes and forces to avoid measurement inaccuracies. Durometer measurement guidelines:- Ensure sample thickness is at least 1/4″ for accurate readings.
- For thinner materials, stack layers to achieve proper thickness.
- Always measure against a rigid core or substrate to prevent deflection errors.
Meridian Laboratory uses calibrated gauges and proper procedures to ensure reliable and consistent measurements. If you’re unsure of a part’s durometer, we can measure and match it—and recommend improvements based on your needs.
Why Is Durometer Important?
Selecting the proper durometer directly affects part performance, longevity, and interaction with other components. In drive or feed applications, a lower durometer may provide better friction, but too soft of a material can over-deform or wear prematurely. Conversely, a harder durometer increases durability but reduces grip. Finding the right balance is key—and that’s where Meridian Laboratory’s experience comes in. With decades of polyurethane expertise, our team can guide you to the optimal durometer for your specific application, whether it’s cushioning, traction, or wear resistance.Why Performance Matters
Even the smallest components—like rollers and wheels—can significantly impact productivity, uptime, and system efficiency. Misfeeds, slippage, and early wear often result from poor material choices. ML6 polyurethane delivers a high-performance upgrade you can rely on. Its unique combination of friction, durability, and dimensional accuracy reduces downtime, improves throughput, and ensures consistent handling through millions of cycles.What Makes Meridian Laboratory ML6 Different?
While Shore durometer scales are standardized, not all polyurethane is created equal. Meridian Laboratory’s proprietary ML6 polyurethane is engineered to outperform conventional urethanes by combining:- High-friction, molded surfaces that eliminate the need for low-durometer materials to achieve grip
- Superior wear resistance, even in high-speed and high-load applications
- Final molded dimensions, meaning no post-grinding and tighter tolerances
- Exceptional bond strength, preventing delamination or tear-off
ML6 often delivers the friction of softer urethane with the lifespan of harder material—without the traditional tradeoffs. The result: rollers, bumpers, and components that last longer and perform better in real-world conditions.
Need help selecting the right durometer or material for your project? Meridian Laboratory’s engineering team is ready to assist with design consultation, material selection, and performance optimization.
Visit our ML6 Product Gallery to explore real-world examples.