DIYUK DIN 127B Split Spring Washers, Zinc Plated Steel Helical Lock Type for Bolts, Nuts & Screws, Anti-Vibration, M6-M30, Packs of 2-200

Zinc plated spring steel split (helical spring) lock washers manufactured to DIN 127, Type B, in ten metric sizes from M6 to M30, formed from a coiled spring-steel ring with two square-cut, slightly offset ends. They sit under the nut or bolt head of a threaded joint and work mechanically, rather than through friction alone, to resist the loosening effect of vibration and repeated movement.

DIN 127 was officially withdrawn from the German DIN catalogue, but the Type B (square-end) profile has remained the de facto industry reference for helical spring washer dimensions ever since, and continues to be manufactured and stocked worldwide under the same designation. Each washer here is pressed from spring steel and zinc plated, giving a bright, general-purpose corrosion-resistant finish.

How they work: when the fastener is tightened, the helical coil is compressed flat and stores spring energy. That stored energy continues pushing back against the bearing face of the nut or bolt head, helping the joint retain clamping tension as it settles in service or is subjected to vibration. The sharp, square-cut ends of the coil also bite very slightly into the mating surfaces on each side, adding a small amount of mechanical resistance to counter-rotation on top of the spring action.

Key Features

• Manufactured to the DIN 127 Type B profile, the long-standing industry reference for helical spring lock washer dimensions, even though the standard itself was formally withdrawn from the DIN catalogue.
• Pressed from spring steel for durability, flexibility, consistent spring-back and reliable clamping force retention under load.
• Zinc plated, giving a bright, general-purpose corrosion-resistant finish.
• Helical coil design stores spring energy when compressed, continuing to push back against the bearing face as a joint settles or experiences vibration.
• Flexible structure for even load distribution and vibration damping, reducing pressure on the fastening elements and protecting them against damage.
• Minimises the effects of vibration and reduces noise.
• Sharp, square-cut offset coil ends bite slightly into the bearing surfaces on each side, adding mechanical resistance to counter-rotation.
• Straightforward metric bore sizing: simply match the washer to the fastener thread size, in the same way as fitting a standard flat washer.
• Available from M6 up to M30, covering the great majority of standard metric fastener sizes used in general engineering and construction.

Specification

Material and finish: spring steel, zinc plated for general-purpose corrosion resistance.

Typical Applications

• Mechanical and electronic constructions, and industrial applications.
• Automotive and general machinery assembly, where bolted joints are subject to ongoing vibration from moving parts or road use.
• General construction and steel fabrication, on structural and secondary fixings where a joint needs to hold its clamping tension over time.
• Agricultural equipment, where machinery routinely sees sustained vibration, shock loading and exposure to the elements.
• Fencing and gate hardware, on hinges, posts and fixings that experience repeated movement and knocks in everyday use.
• Any bolted joint, in a workshop, garage or on site, that is subject to vibration or repeated movement and would otherwise be prone to working loose over time.

Installation Guidance

Easy to install: match the washer bore to the corresponding metric bolt, screw or stud size (for example, fit an M10 washer to an M10 fastener) and place it directly under the nut or bolt head before tightening. Tighten the fastener to the correct torque for the joint; the washer is compressed flat as it is tightened, which is what allows the coil to store spring energy and continue pushing back against the bearing face in service.

Common Questions

Which size do I need?
Match the washer to the thread size of your bolt, screw or stud, for example an M10 washer for an M10 fastener. Ten sizes are available, from M6 to M30.

Where does the spring washer go?
Directly under the nut or bolt head, before tightening. As the fastener is tightened, the coil is compressed flat and keeps pushing back against the bearing face in service.

What does DIN 127 Type B mean?
Type B is the square-end profile of the DIN 127 helical spring washer: the square-cut ends bite slightly into the bearing surfaces on each side.

What finish do they have?
The spring steel washers are zinc plated, giving a bright, general-purpose corrosion-resistant finish.

What pack sizes are available?
Every size comes in packs of 2, 10, 25, 50, 100 or 200 washers.