Retaining washers, often referred to as “Star Lock Washers” when designed for shafts, are specialized fasteners used to secure components onto a shaft while resisting axial movement. Unlike traditional lock washers that prevent loosening, these washers provide a positive retaining force. They are characterized by multiple flexible teeth or prongs that grip the shaft aggressively once installed, preventing parts from sliding off. While “star lock washer” can sometimes refer to a general tooth lock washer (like DIN6797), in the context of shafts, it specifically implies a push-on or grip-on retainer with internal teeth.

Definition

A “Retaining Washer Star Lock Washer for Shaft” is a push-on fastening device designed to provide a quick, permanent, and secure means of retaining components on a shaft, stud, or axle. These washers feature a central hole with inward-pointing, flexible, and sharply angled teeth (often resembling a star or multi-pronged design). When pushed onto a plain shaft (without threads or grooves), these teeth deflect and then bite firmly into the shaft material, creating a strong resistance to pull-off and preventing axial movement of the component being held. They eliminate the need for threads, grooves, or cotter pins in many applications.

Advantages

• Quick and Easy Assembly: Simply push onto the shaft; no special tools, threading, or grooves are typically required, significantly speeding up assembly time.
• Strong Axial Retention: The aggressive grip of the teeth provides excellent resistance to axial pull-off, securely retaining components.
• Eliminates Machining Costs: No need for expensive machining operations like threading, grooving, or drilling for cotter pins on the shaft.
• Cost-Effective: Generally less expensive than other retaining methods (e.g., circlips with grooves, threaded nuts and bolts).
• Versatile: Suitable for use on plain shafts made from various materials (metal, plastic, wood).
• Vibration Resistance: The tight grip helps to dampen vibrations and prevent rattling of components on the shaft.
• Permanent Fastening: Once installed, they are typically difficult to remove without damage, making them ideal for permanent assemblies (though removable versions exist for specific designs).

Applications

• Axle and Wheel Assemblies: Commonly used to secure wheels, gears, bearings, or other components onto plain axles in toys, trolleys, small vehicles, and casters.
• Appliances: Used to attach knobs, levers, or other rotating parts to shafts in household appliances like washing machines, dryers, and blenders.
• Shaft Retention in Motors/Pumps: Securing impellers, fans, or other rotating parts onto motor or pump shafts.
• Furniture Assembly: Retaining components on tubular or rod-like structures in furniture.
• Tooling and Fixtures: Used in various workshop tools and fixtures to secure handles or adjustable components.
• Agricultural Equipment: For securing various parts onto shafts in farming machinery.
• Electronic Equipment: Retaining dials, indicators, or small sub-assemblies on control shafts.