STAUFF Safety Lock Washer (Type SI DIN 463 – Standard Series)

Description

Operating Principle and Application

The STAUFF Safety Lock Washer (Type SI DIN 463 – Standard Series) performs the essential function of a mechanical locking device. Its primary purpose is to prevent the accidental loosening of hexagon head bolts, specifically those classified as Type AS. During installation, system safety is ensured through controlled plastic deformation of the two tabs integrated into the component. Correct installation requires the longer tab to be bent downwards against the side of the clamp body. At the same time, the shorter tab must be bent upwards so that it rests against one of the flat surfaces of the hexagon bolt head. This configuration creates a permanent physical and structural restraint that prevents rotation of the threaded fastener and ensures maximum fastening stability over time, eliminating the risk of loosening caused by vibrations in hydraulic circuits.

Construction and Dimensional Features

Designed strictly in accordance with the DIN 463 reference standard, this two-tab safety lock washer features specific tolerances and precise metric dimensions, suitable for demanding applications. The inside hole diameter (ØD1) is 6.4 mm, while the outside diameter of the circular body (ØD2) is 12 mm. The material thickness (S) is set at 0.5 mm to allow easy manual bending during installation while maintaining full structural integrity. The two tabs have a width (B) of 7 mm. The longitudinal extension (L1) of the long tab is 18 mm, while the extension (L2) of the short tab is 9 mm. A bend radius (R) of 4 mm is also provided at the base of the tabs; this feature minimises stress concentration during bending and prevents metal fracture.

Compatibility and Application Sectors

The STAUFF Safety Lock Washer (Type SI DIN 463 – Standard Series) is suitable and fully compatible with all clamp group sizes belonging to the Standard Series. This range fully covers STAUFF Groups from size 1 to size 8, exactly equivalent to DIN Groups from size 0 to size 8. The combined use of this retaining component with standardised fastening systems and Type AS hexagon head bolts ensures optimum retention for all compatible hydraulic installations within these sizes.

Material Specifications and Surface Finishes

To meet a wide range of environmental and mechanical resistance requirements, the component is available in two primary material variants (Material Code). The first option, identified by code W3, is manufactured from solid Carbon Steel and is treated with a protective zinc/nickel-plated surface finish. This finish provides a significant increase in resistance to galvanic corrosion. The second option, identified by code W5, is manufactured entirely from high-grade V4A Stainless Steel, with numerical designation 1.4401/1.4571 and equivalent classification AISI 316/316 TI. This alloy provides extremely high corrosion resistance for the most chemically and physically aggressive environments. Alternative finishes or materials are available upon request by contacting STAUFF directly for custom specifications.

Summary Technical Table of the Main Features of the STAUFF Safety Lock Washer (Type SI DIN 463 – Standard Series)

Product Codes