Load springs can be preloaded to obtain various degrees of deflection and permit optimum ride “softness.” Maximum capacity loads will deflect spring-loaded wheels from 3/8” to ¾”, depending on caster and spring selected. Medium duty casters feature top plate and yoke base of ¼” steel plate and a ½” axle; swivel sections contain cold formed, double ball bearing raceways to minimize wear. Heavy duty and extra heavy duty casters feature top plate and yoke base of AISI 1045 drop forged steel for strength and reliability; ½” axle (¾” axle for extra heavy duty casters). Swivel sections contain “deep-groove” load raceways to provide optimal performance under extreme loads.