M3 Internal Tooth Lock Washer, 316 Stainless Steel - ILWA4M3

The Internal Serrated Tooth Lock Washer Stainless Steel is available in 7 sizes (M3 to M12) and is a washer with teeth around its inner edge. The teeth bite into the fastener and the surface to resist loosening, and the smaller outer diameter is useful where space is tight.

This listing has 7 variants covering sizes M3 to M12. Variants are supplied in packs of 100 to 500, depending on size.

Made from 316 (A4) stainless steel, the grade normally specified for chloride-exposed work such as coastal installations, swimming pools, marine fittings and food-processing plant. Metric sizes are written M followed by the nominal thread diameter in millimetres, so M10 is a 10 mm thread.

Austenitic stainless steel is generally non-magnetic, although cold-worked parts can show weak magnetism. In wet conditions, keep stainless steel apart from aluminium and galvanised steel with a washer or sleeve, to reduce the risk of galvanic corrosion.

Where this product is used

• Bulk jobs and trade or maintenance stores buying in larger packs
• Electrical and earthing connections
• Marine and washdown fittings
• Small assemblies and screw heads where outer diameter is limited
• Larger sizes for frames, plant and structural fixings
• Small sizes for enclosures, instruments and light fittings

Features

• Resists loosening under vibration
• Pack quantities to suit trade and bulk buying: packs of 100 to 500
• Teeth around the inner edge bite into the surface
• Metric thread sizes match the nuts, bolts and tapped holes in most Australian-supplied equipment
• A4 (316) stainless steel with molybdenum, for coastal and chloride-exposed settings
• Choice of 7 sizes, M3 to M12

Key specifications

Selecting the right option

Teeth mark the surface they bite into, so avoid them on finished or painted faces. Internal teeth are usually chosen for screw heads and where the outer diameter must stay small. For indoor and general outdoor use where chlorides are not a concern, the A2 (304) version is the lower-cost option: Metric Internal Tooth Lock Washer - 304 Stainless Steel.