Precision Sealed Bearings are available with a 5/8" bore. With double seals, the precision ground and hardened components are good for high speeds and heavy duty applications.
Ground Sealed Bearings have a machined housing and a flanged outer race. Their unique inner race construction accommodates a 3/4" bore and 1-3/8" OD unavailable in a precision bearing.
Standard Bearings are available with 3/4", 5/8" and 1/2" bores. They have an integral metal seal within a stamped steel housing and are used for moderate speeds with light to medium loads.
1-5/8" OD PRECISION WHEEL BEARING: This bearing has a 3/4" ID, is sealed, has a hardened and ground raceway, and is an excellent alternative to the more expensive sealed Tapered Roller Bearing. Same top quality as our 5/8" ID precision bearing.
TAPERED ROLLER BEARINGS (TRB), SEALED OR WITH DUST SHIELD: Tapered Roller Bearings, used for more strenuous applications, use a Cup (Race) pressed into the wheel, a Cone (Bearing) and, for the non-sealed type only, a Dust Shield. TRBs have a bore of 3/4" but can be reduced to 5/8" with a reducer bushing.
The Sealed Tapered Roller Bearing provides protection from the elements over and above that offered by the non-sealed type with Dust Shield. When you purchase Azusa Wheels with a non-sealed bearing, Dust Shields are provided.