Grease Nipples - Metric Coarse

Grease nipples are small but very important fittings used in automotive and other mechanical systems to enable lubricant to be fed into the system. As the name suggest, the lubricant is usually grease.

Grease nipples contain a sprung ball bearing inside the nipple body. When a grease gun is connected to the grease nipple and pressure applied, the bearing compresses to allow the lubricant to flow into the joint.

Metric is the most common thread type in production today. Usually specified as M then a number x another number. This signifies the thread diameter and the length of the fastener.

For example, M4 x 30 means that the major thread diameter (the external distance across the outside of the thread) is 4mm and the length is 30mm. Length is usually measured from the underside of the fastener head.

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