A2 Stainless Steel Split Lock Spring Washers - DIN 127B (M2-M22)

Guard bolted joints against loosening with our A2 Stainless Steel Split Lock Spring Washers, manufactured to the DIN 127, Type B dimensional standard. Pressed from austenitic A2 stainless steel and cold-formed into a helical coil with two flat, square-cut ends, each washer combines spring tension with a mechanical bite to keep nuts and bolts tight under vibration, repeated movement and thermal cycling.

DIN 127 was formally withdrawn from the current German DIN catalogue in the early 1990s, but the Type B (square-end) profile remains the de facto industry reference for split lock washer dimensions and continues to be manufactured and stocked worldwide to the same sizing. When the washer is compressed flat under a tightened fastener, the coiled ring stores spring energy and continues pushing back against the bearing face, helping to maintain clamping tension as a joint beds in or experiences vibration. The sharp, square-cut ends also key very slightly into the mating surfaces, adding a mechanical resistance to counter-rotation on top of the spring action.

Stocked across 14 sizes from M2 up to M22, with individual washer weights ranging from roughly 0.03g (0.001oz) for the smallest M2 washer up to around 16.5g (0.58oz) for the largest M22 washer, there is a size to suit fixings from delicate electronics and instrument work right through to heavy structural and automotive assemblies.

Key Features

• Vibration and loosening resistance: the helical spring action continues to load the joint after tightening, helping to resist the gradual loosening caused by vibration, shock and repeated movement.
• A2 stainless steel construction: austenitic A2 stainless steel resists rust and general atmospheric corrosion far better than plain or zinc-plated carbon steel, making these washers suited to damp, humid or outdoor conditions.
• Dual locking action: spring tension plus a sharp, square-cut biting edge, working together to resist both loosening and counter-rotation.
• DIN 127B dimensional standard: manufactured to the long-established Type B (square-end) sizing, so fit and function are consistent and predictable size after size.
• Reusable and low-maintenance: stainless construction means no plating to wear through or flake off, and washers can typically be reused across multiple assembly/disassembly cycles provided they have not been fully flattened.
• Genuinely wide size range: 14 sizes held in stock, from M2 up to M22, covering fine-pitch electronics and instrument fixings through to heavy-duty structural and automotive bolts.

Material & Corrosion Resistance

These washers are manufactured from A2 (also widely known as 18-8) austenitic stainless steel, an alloy of roughly 17.5-19.5% chromium and 8-10.5% nickel that gives excellent resistance to rust and general corrosion in indoor, outdoor and freshwater environments.

Typical Applications

• Automotive assembly and repair where corrosion resistance and vibration resistance both matter.
• Industrial and agricultural machinery subject to continuous vibration or cyclic loading.
• Structural steelwork, fencing and outdoor construction exposed to weather.
• Electrical enclosures, control panels and cabinet hardware where a non-rusting fixing is required.
• Instrumentation, electronics and precision assembly using the smaller M2-M5 sizes.
• General DIY, maintenance and repair work around the home and workshop.

Specification

Dimensions below follow the DIN 127, Type B standard. Metric figures are shown first, with the imperial (inch) equivalent in brackets; inner diameter (d1) and thickness (s) are given as a tolerance range, outer diameter (d2) as the standard's maximum permitted value.

Standard: DIN 127, Type B
Product type: Helical spring split lock washer
Material: A2 (18-8) austenitic stainless steel
Finish: Plain (natural stainless, uncoated)
Corrosion resistance: Excellent for general-purpose and freshwater use
Thread direction: For right-hand threads only
Sizes held in stock: M2, M3, M4, M5, M6, M7, M8, M10, M12, M14, M16, M18, M20, M22

Installation & Fitting Guidance

• Select the washer whose size matches the bolt, screw or stud thread (for example, an M8 washer for an M8 fastener).
• Fit the washer directly under the nut or bolt head, against the bearing surface, before tightening to the correct torque for the application.
• Tighten until the washer is fully compressed flat.

Order dispatched fast from our UK warehouse. Add these A2 stainless steel DIN 127B split lock washers to your basket today for a corrosion-resistant, vibration-resistant fixing you can rely on.