Value Collection SIW8X2000-050BX M20 Lock Washer

Product Description

The VALUE COLLECTION SIW8X2000-050BX is a stainless steel internal tooth lock washer designed for use with M20 fasteners. It features a serrated internal tooth configuration that bites into mating surfaces to resist loosening under vibration and dynamic loading. Manufactured from Grade 18-8 austenitic stainless steel (Austenitic Grade A2), this washer carries an uncoated finish suitable for corrosion-resistant installations. The 21mm inner diameter fits M20 screws and bolts, while the 33mm outer diameter provides adequate bearing surface. Installers working in wet, outdoor, or chemically active environments favor the A2 stainless grade for its resistance to rust and oxidation. This washer conforms to DIN 6797 and DIN 6798 standards.

Internal tooth lock washers in this size range are used across mechanical, structural, and electrical assembly applications wherever an M20 fastener requires positive locking without a separate locking element. Common install scenarios include panel mounting, equipment framing, pump and motor assemblies, and general fabrication work. The internal tooth design keeps the outer perimeter clear, making it well suited for applications with close hole-to-edge tolerances or finished surface aesthetics. Electricians, millwrights, pipefitters, and general maintenance technicians regularly specify this type of washer.

Key Features

• Internal serrated teeth grip the fastener shank and mating surface to resist rotation and loosening
• Grade 18-8 austenitic stainless steel (A2) provides corrosion resistance without a protective coating
• 21mm inner diameter sized for M20 screws and bolts
• 33mm outer diameter with 1.4mm thickness per DIN 6797 and DIN 6798 specifications
• Uncoated finish — no risk of coating failure or galvanic incompatibility in stainless assemblies
• Serrated tooth geometry distributes clamping load and maintains preload under vibration

Compatibility

Designed as a standard-profile internal tooth lock washer for use with M20 screws, bolts, and fasteners in assemblies requiring DIN 6797 or DIN 6798 compliant locking hardware.

Installation Notes

Install with the teeth facing the fastener head or nut, not the workpiece surface, unless the assembly design specifies otherwise. Ensure mating surfaces are free of debris and excess lubricant, as heavy lubrication can reduce the locking effectiveness of the serrated teeth. Torque the fastener to the value specified in the assembly drawing or engineering standard for the fastener grade and size. Wear appropriate hand protection when handling washers in bulk, as tooth edges are sharp.