What are grease nipples?
Grease nipples, also known as grease fittings or zerk fittings, are permanent fittings on mechanical systems that supply lubricant to components like bearings. They function as a valve, allowing grease to be fed into the system via a grease gun – opening under pressure and closing afterward.
A grease nipple is fitted to the bearing housing using either a threaded connection (which can be sourced from Milsons) or by utilising a straight push-fit method – where the grease nipple is hammered into place. Because grease nipples are permanent fittings, it is important to choose the correct one.
Factors to consider when choosing your grease fitting:
When selecting grease fittings, it is important to consider the following factors:
- Location of grease nipple: Ensure easy access for a grease gun and check for nearby moving parts.
- Environment: Consider temperature and moisture levels to determine the appropriate finishing on the grease nipple.
Milsons offers a range of finishings, including zinc to improve corrosion resistance.
Dimensions to consider when choosing grease fitting:
When selecting a grease fitting, there are three key dimensions to consider:
- Thread length (labelled ‘B’ in the diagram above): This is the length of the male thread between the hexagonal base of the grease nipple and the bottom. This dimension is quite critical as it serves as the primary connection to the bearing and can be a potential point of failure. Milsons offers Metric, BSP and UNF/UNC thread types.
- Angle of grease fitting: This refers to the angle between the threaded part of the fitting and the nipple. Angled grease nipples are useful because they can give you greater accessibility and reach with a grease gun. Milsons offers four fitting angles: Straight, 90 degree or right angle, 45 degree and 67 degree.
- Overall Height: Dimension A refers to the overall height of the grease nipple. It is measured from the base of the fitting to the highest point of the head when the fitting is sitting flush on a flat surface prior to installation. This is an important consideration, especially where space around the lubrication point is limited. Ensuring adequate clearance helps allow access for the grease gun coupler once the fitting is installed.
With a straight fitting, the grease gun is applied from the top. A 90-degree fitting allows access from the side. Fittings with a 45-degree or 67-degree angle enable grease gun access at an angle, simplifying the greasing process.
The data provided in this document is for general guidance only and should not be solely relied upon when working to stringent specifications. We recommend consulting with qualified experts regarding any technical queries. This may change without written notice
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