Choosing the wrong hardness is one of the most common causes of premature polyurethane part failure. A wheel cast at 95 Shore A instead of 70 can damage floors; the opposite choice will flatten and deform within weeks. This guide summarises the practical approach our casting team has used since 1998.
What Is Shore Hardness?
Shore hardness measures a durometer indenter's resistance to penetration. Elastomers use the Shore A scale: 0 is softest, 100 hardest; above 95 Shore A the Shore D scale takes over. At Beray Makina we formulate our polyurethane products across the 30-98 Shore A range to match each application.
What Changes Across 30-98 Shore A?
30-50 Shore A (soft): Maximum impact absorption and surface protection — vibration chocks, impact bumpers, support pads on lines carrying delicate surfaces.
55-70 Shore A (medium): General-purpose wheels, conveyor roller coverings and non-marking contact surfaces. The best balance of flexibility and load capacity.
75-85 Shore A (hard): Heavily loaded forklift and pallet truck wheels, scrapers, guides. Wear resistance rises while damping falls.
90-98 Shore A (very hard): Slitting wheels, die springs, in-mould support parts. Behaves almost rigid; preferred in cutting and forming applications.
Quick Selection by Application
Wheels: 65-75 Shore A where floors are sensitive, 80-92 where load comes first. Roller coverings: 60-85 depending on nip pressure and marking requirements — see our roller coating page. Die springs and chocks: 85-95 for spring action, 40-60 for vibration damping.
Three Common Mistakes
1. Assuming hardest means most durable: Tear resistance does not always rise with hardness; under impact loads, medium hardness often lasts longer.
2. Ignoring temperature: Polyurethane works from -45°C to +80°C; it softens when hot and stiffens when cold. Applications near ovens should be specified one step harder.
3. Treating dynamic loads as static: Parts under continuous compression need low compression-set formulations — a recipe issue independent of hardness.
Let us help you specify the right hardness: Beray Makina casts custom polyurethane across 30-98 Shore A. +90 (224) 411 03 24 | beray@beraymakina.com