What Is a Grease Nipple?
A grease nipple is a part that is attached to a grease-lubricating machine and used as a grease supply port (inlet) to supply grease using a grease gun or other lubricating equipment.
Lubrication means to supply viscous semi-solid (paste) lubricant such as grease to a machine. Lubrication refers to supplying lubricants such as liquid oil.
Uses of Grease Nipples
Grease is a type of lubricant used in roller bearings (rolling bearings), metal bearings, and bushings with plain bearings where large loads are applied even at low speeds. Grease nipples are installed on machines and parts that are lubricated with grease and need to be replenished.
Generally, grease-lubricated machines are pre-filled with a specified amount of grease at the time of assembly. However, the amount of grease decreases with the passage of machine operation time. Therefore, periodic replenishment of grease is necessary.
By installing grease nipples, grease can be easily supplied from outside the machine without disassembling the machine. Some locations that require greasing are easy to work with, while others are not.
It is necessary to select and use grease nipples with good workability in anticipation of grease injection work. For this reason, there are several types of grease nipple tip shapes.
Principle of Grease Nipples
The tip of the grease nipples has a check valve structure to prevent backflow of injected grease. A small steel ball is incorporated inside the grease nipple tip.
The ball is constantly pressed against the body by a spring to seal grease from leaking. When grease is applied by applying pressure using a grease gun, the grease pushes the ball, and grease flows in through the gap between the inlet port and the ball.
Types of Grease Nipples
Shape of Grease Nipple
- Types 1 and 2
Types 1 and 2 are straight types, in which the center of the mounting hole is coaxial with the inlet port, and the mouthpiece attached to the hose of a grease gun, etc. is pressed straight into the hose for injection. - Type 3
Type 3 is mounted at a 45° angle to the center of the mounting hole. - Type 4
Mounting holes are tilted 65° to 67.5° to the center of the mounting holes. - Type 5
Mounted at a 90° angle to the center of the mounting hole.
Select grease nipples from types 1 to 5 that can be easily inserted into the grease gun hose and fitting and that are easy to work with.
Other Information on Grease Nipples
How to Grease a Grease Nipple
A grease gun is generally used to grease a grease nipple. A manual grease gun is operated by holding the handle and moving it back and forth to pressurize the grease tube (a tube containing grease) and inject grease. In addition to manual grease guns, electric grease guns are also available.
There are different types of grease guns, but regardless of the type, be careful about the angle between the grease nipples and the grease gun inlet when lubricating. If the angle is slanted, lubrication cannot be performed correctly and grease will overflow from the gap between the lubrication ports. Lubricate the grease nipples and grease gun slot with care so that they are straight.