Product Description
Bearing
Frequently Asked Questions
Q: What do ZZ shields mean and how do they differ from 2RS rubber seals?
A: ZZ designates metal (steel) shields on both sides of the bearing. Unlike 2RS rubber contact seals, ZZ shields do not contact the inner race, leaving a small air gap. ZZ shields provide lighter contamination protection and allow slightly lower operating temperatures but offer less contamination exclusion than rubber seals. The 6307-ZZ runs cooler and supports higher speeds than the 6307-2RS, making it suitable for high-speed applications or when heat dissipation is critical.
Q: What are the dimensions and specifications of the 6307-ZZ bearing?
A: The 6307-ZZ maintains the same core dimensions as other 6307 variants: 35 mm bore, 80 mm outer diameter, and 21 mm width. It features a single row deep groove design, steel cage, AISI 52100 bearing steel races, and dual metal shields. The bearing comes factory lubricated and is compatible with equipment across Crown, Toyota, Raymond, Yale, Hyster, and Clark brands.
Q: When should I choose the 6307-ZZ over the sealed 6307-2RS variant?
A: Choose the 6307-ZZ if your pallet jack operates at higher speeds, in warmer ambient temperatures, or where rapid heat dissipation is needed. The 6307-ZZ also suits dry warehouse environments where contamination risk is low. Do not use 6307-ZZ on wet docks, outdoors, or in dusty conditions without additional equipment protection. For most standard manual pallet jack duty, the sealed 6307-2RS offers better protection.
Q: Are the 6307-ZZ and 6307-2RS interchangeable in the same equipment?
A: Yes, both bearings share identical outer dimensions (35 mm bore x 80 mm outer diameter x 21 mm width) and are direct physical replacements. However, they should not be considered functionally interchangeable for all environments. The sealed 2RS is better for contamination-prone settings, while ZZ suits high-speed and high-temperature applications. Verify your equipment duty cycle before switching variants.
Q: What is the expected service life of the 6307-ZZ in a manual pallet jack application?
A: In typical warehouse duty, the 6307-ZZ bearing should deliver 2 to 4 years of service, which may be shorter than sealed variants if the environment contains dust or moisture because the metal shields offer less protection. Operational lifespan depends on ambient cleanliness, temperature, and load conditions. Monitor for increased play, noise, or friction as indicators of bearing degradation.