Part No. Z6MM Lube Zerk Fittings, Notes 6mm zerk

Z6MM is a 6mm metric grease zerk (Alemite-style) fitting used on driveshaft U-joints and other components with 6mm grease port threads. The 6mm thread is a metric standard found on European and some Asian driveshaft U-joints that use metric-threaded grease ports rather than the common imperial .250-28 thread used on domestic U-joints.

Why grease zerks matter: a clogged, stripped, or missing zerk prevents grease from reaching the U-joint needle bearings. Without periodic lubrication, the needles run dry, heat, and fail -- often within a short service interval under heavy use. A missing or damaged zerk should be replaced before the next lube interval.

• Thread: 6mm metric
• Style: Straight zerk (Alemite)
• Application: European metric U-joints, industrial components with 6mm grease ports

Do not attempt to thread a .250-28 imperial zerk into a 6mm metric port or vice versa -- the threads are incompatible and will strip the port. Confirm thread specification before installing replacement zerks.

See all universal joints for greaseable U-joints requiring lube fittings.