Grease fittings, the metal pieces used to feed lubricant into machinery accurately and under high pressure, aren’t necessarily part of every person’s daily conversation. However, they do crop up in our lives much more frequently than you probably realize. Grease fittings are commonly used in tractors, lawnmowers, automatic pool covers, marine engines, and mining equipment to properly and consistently supply machinery with lubricant when shaft diameters exceed 20 millimeters. They’re provided by many companies like De-Sta-Co distributors and can be found in the DeStaCo catalog.
How Do Grease Fittings Work?
Grease fittings are permanently installed by threaded connections ad leave a nipple connection that can attach to a grease gun. When a grease gun is attached, a small bearing ball in the filling moves back against the force of its retaining spring and opens a valve to allow the passage of lubricant. When the pressure ceases, the valve closes. This excludes dirt and prevents grease from escaping the fitting. Because the fitting is convex, the grease gun can seal against it easily from many angles, but still tightens enough to force pressurized grease into the fitting. Grease fittings are typically made from zinc-plated steel, stainless steel, or brass.
What Did We Do Before Grease Fittings Came Around?
Before the first grease fitting, created by Oscar U. Zerk in 1929, bearings were lubricated through much more maintenance-intensive processes that provided less effective lubrication. For example, plain bearings were used in the 19th and early 20th centuries with cross-drilled holes to receive oil or grease. This delivered oil without pressure, and was generally less effective.
How Are Grease Fittings Used Now?
Since the 1920s, sealed bearings have largely replaced grease fittings for use in many products. However, grease fittings are still common for some applications because they are cost-effective, simple, and long-lasting. Typically, they can be seen on commercial products because commercial users usually have plan and enforcement for lubricating schedules.
Grease fittings are an essential part of our commercial world, and you encounter them more often than you realize.