Unquestionably, the urethanes have outstanding abrasion resistance. They outwear metals, plastics, and other rubbers by a wide margin, often by 8 to 1 or more.
Abrasion is caused by many actions, such as impingement, erosion, impact, scuffing, and sliding. Add to that the many variables which affect the abrasion rate such as mass, pressure, temperature, velocity and lubricity. It's obvious that abrasion, then, is very application specific. There are a few standard tests such as the National Bureau of Standards (tires) and the Tabor Abrasion (floor tile) which provide guidance but, in general, specific tests have to be designed to closely approximate the intended service. Here are some empirical conclusions we have formed over the years of following field tests:
· Soft compounds (55A-85A) last longest in particle impingement types of service.
· Medium durometer compounds (80A-95A) of medium resilience last longest in abrasive slurry pump impellers, etc.
· 90A-95A durometer compounds work best in impact and sliding types of abrasion found in sand, gravel, coal and ore mining applications.
· The very hard compounds (65A-75D) durometer work best in bushing and bearing applications in wet or dry environments, often where sand, grit or mud are present.
There is no substitute for a field test of 2 or 3 chosen compounds. With our experience and knowing your field performance, we can help you select test candidates.
LEFT: Urethane hand wheels provide outstanding impact resistance and a comfortable grip, even in below-zero temperatures. RIGHT: Cable guides resist wear and protect the cables of the St. Louis Gateway Arch.
Abrasion: Gallagher urethane vs. SBR rubber.