Spring Lock Washers

Spring Lock Washers for Australian General Fastening

Spring lock washers (also called split lock washers or split rings) are the everyday locking washers fitted under bolt heads and nuts to provide modest resistance against fastener loosening from vibration. The split-ring construction creates spring tension when the fastener is tightened, with the cut edges biting into the bolt head and the joint surface to resist rotation. For Australian general fastening where serious safety washers (Schnorr, Nord-Lock) would be over-specification, spring lock washers provide adequate locking at low cost. AIMS Industrial supplies spring lock washers in metric and imperial sizes from Hobson and Bremick.

How spring lock washers work

The split ring has cut ends that are slightly offset axially — when the fastener is tightened, the ring is compressed flat, with the cut edges digging into the bearing surfaces above and below. The combination of spring tension (resisting fastener relaxation) and the cut-edge bite (resisting rotation) provides modest locking action. Under sustained heavy vibration, spring lock washers can fully relax (squashed flat with no spring action remaining) and provide minimal continuing locking — for serious vibration applications, proper safety washers are required.

The spring lock washer types we stock

• Standard split lock washers — the everyday spring lock washer in metric and imperial sizes
• Heavy-duty split lock washers — thicker section for higher clamping load and stronger spring action
• High-collar lock washers — taller section providing additional stand-off and stronger locking
• Toothed lock washers (star washers) — the related but different category — see safety washers

Materials and finishes

• Spring steel zinc-plated — the everyday workshop choice for indoor and protected applications
• Stainless steel 304 and 316 — for corrosive and food-grade environments
• Phosphor bronze — for non-magnetic and electrical applications
• Black oxide finish — for non-reflective and decorative applications

Sizing

Spring lock washers are sized by the bolt diameter they fit. Common metric sizes range from M3 through M30. Imperial sizes from #4 through 1 inch and beyond. The washer's inside diameter, outside diameter, and thickness must match standard fastener dimensions for the bolt being used; mismatched sizes ride poorly under the bolt head and provide reduced locking action.

Where spring lock washers earn their place

• General workshop fastening — the everyday choice where vibration is moderate
• Indoor mechanical assembly — equipment where vibration isn't constant or severe
• Light machinery — applications where Nord-Lock or Schnorr washers would be over-specification
• Production assembly — high-volume work where the simplicity and low cost matter

Where spring lock washers DON'T earn their place

For serious vibration applications, spring lock washers are inadequate:

• Heavy machinery and earth-moving equipment — constant shock loading exceeds spring washer capability; use Schnorr or Nord-Lock
• Vehicles and rolling stock — sustained vibration causes spring washers to relax over time
• Critical safety fixings — anywhere fastener loosening is a safety risk
• High-temperature applications — spring tension reduces at elevated temperature

For these applications, see our Schnorr safety washers, Nord-Lock wedge washers, or other dedicated safety washer types.

Brands stocked at AIMS

Hobson and Bremick cover the spring lock washer range across the standard sizes, materials, and finishes. Bulk packs are available for production work; trade pack quantities for general workshop use.

Installation

Spring lock washers fit under the bolt head or under the nut, with the split-ring's tapered side facing the bolt head or nut. Tighten the fastener to the specified torque — the spring action of the washer is created during tightening. Don't reuse spring lock washers — once compressed flat, the spring action is reduced or lost, and reuse provides minimal continuing locking benefit.

Companion ranges at AIMS

Spring lock washers sit alongside our broader fastener range — see safety washers, retaining washers, mudguard washers, and square washers for the related products.

Need help selecting between spring lock washers and dedicated safety washers for a specific application? contact our team — we'll match by vibration severity, application, and load.