SOX (NBR) Rubber (Standard Insert) - Nitrile Butadiene (Buna N) Rubber is a flexible elastomer material that is oil resistant, resembles natural rubber in resilience and elasticity.
Urethane - Greater torque capability than NBR (1.5 times), provides less dampening effect, and operates in a smaller temperature range. Good resistance to oil and chemicals. Not recommended for cyclic or start/stop applications.
Hytrel® - Flexible elastomer designed for high torque and high temperature operations. Excellent resistance to oil and chemicals. Not recommended for cyclic or start/stop applications.
Bronze - Rigid, porous oil-impregnated metal insert exclusively for low speed (max 250 RPM) applications requiring high torque capabilities. Not affected by extreme temperatures, water, oil, or dirt.
* All Sizes (except L035) shore hardness = 80A, Size L035 shore hardness = 60A
** Sizes L050 to L110 shore hardness = 55D, Sizes L150 to L225 shore hardness = 90-95A
Note: In addition to solid center spiders (most common), open center spiders are also available (to allow shafts of the driver and driven to be positioned within a short distance). Open center spiders offer shaft positioning flexibility but have a lower RPM capacity (1,750 RPM maximum for NBR, 3,600 maximum for Urethane and Hytrel®).