Skip to content
Washers · DIN 127 · Application guide

What Are Spring Lock Washers Used For?

Typical applications, the industries that specify spring lock washers, and how to choose the right size, material and finish for the joint.

Spring Lock Washers are used for load distribution and anti-loosening under a bolt or nut. They are manufactured to DIN 127, and selection is driven by the nominal bolt size, the fit and tolerance the assembly requires, and the service environment.

Primary duty
Load distribution and anti-loosening under a bolt or nut
Governing standard
DIN 127
Nominal bolt size range
M2 to M36
Category
Washers

Application notes are general engineering guidance. Verify the property class and any approval requirement against your own design calculation.

What Are Spring Lock Washers Used For? application image

Application guide for Spring Lock Washers to DIN 127. The core duty of the type is load distribution and anti-loosening under a bolt or nut. The typical industries, the how-to-specify checklist, assembly practice and the exclusion cases are set out below. Stocked across roughly M2 to M36, they cover general to heavy-duty work.

Typical Applications for Spring Lock Washers

The most common settings where these are specified:

  • Bolted structural joints: spreading load over soft or oversized holes and protecting the surface.
  • Vibration applications: spring and serrated types that maintain tension under cyclic load.
  • Timber & soft materials: large-OD types that prevent pull-through.
  • General machine building: fastening covers, brackets, motors and sub-assemblies on production equipment.
  • Maintenance & repair (MRO): a stocked size for servicing existing plant where the original fastener spec must be matched.

How to Specify Spring Lock Washers for Your Application

  • Size: Match the nominal size to the mating thread or hole. This product spans M2–M36; check the full table below for the exact dimensions of each size.
  • Type & OD: Select flat for load spreading, spring/serrated for anti-loosening, or fender/large-OD for soft or oversized holes.
  • Environment: For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient.
  • Standard: This product is supplied to DIN 127. Quoting the standard on your order guarantees interchangeable dimensions between suppliers.

Installation & Assembly Practice

  • Place the washer under the rotating element (usually the nut) so tightening does not score the surface.
  • Chamfered-hole side of a hardened washer faces the bolt head fillet.
  • On serrated-flange hardware, do not add a plain washer — it defeats the serrations.

Common Selection Mistakes with Spring Lock Washers

  • Relying on a spring washer for locking on class 8.8+ joints — at high preload it flattens and adds nothing.
  • Choosing an OD too small for soft material, so the head pulls through or embeds.

Where Spring Lock Washers Are Not the Right Choice

A washer does not replace a locking feature on its own in severe vibration, and a spring washer adds little clamp on high-strength joints.

Custom manufacturing · Made to drawing

Need a spring lock washers outside the standard range?

Bore and outside diameter are set by the joint rather than by the bolt, which is why an off-table size is so often the right answer. Made by stamping or punching.

Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

Custom washer manufacturingSend a drawing

Technical Drawing

Customize the parameters below — every spec field is editable, and the drawing redraws to match the values you choose. Changing the size will snap the other fields to that size's standard values; you can then override any individual value.

Dimensioned line drawing of M2 Spring Lock Washers to DIN 127. Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.
Inner diameter d1 min (mm)
2.1
Outer diameter d2 max (mm)
4.4
Width b (mm)
1.6
Thickness s (mm)
0.5
Opens a short step to confirm the exact specification before you enter contact details.

Request a Quote

Click “Request this configuration” under the drawing to confirm the exact specification, then add your contact details. You can also send the request without a specification — but only an accurate selection gets an accurate quote.

Request a Quotation

Specification
Business Information

Dimensions & Specifications (DIN 127)

For bolt sizeInner diameter d1 min (mm)Outer diameter d2 max (mm)Width b (mm)Thickness s (mm)Reference standard
M22.14.41.60.5DIN 127
M2.52.65.12.00.6DIN 127
M33.16.22.00.8DIN 127
M3.53.67.02.50.8DIN 127
M44.17.62.51.0DIN 127
M55.19.23.01.2DIN 127
M66.111.84.01.6DIN 127
M77.113.14.01.6DIN 127
M88.114.85.02.0DIN 127
M1010.218.16.02.2DIN 127
M1212.221.17.02.5DIN 127
M1414.224.18.03.0DIN 127
M1616.227.49.03.5DIN 127
M1818.229.49.03.5DIN 127
M2020.233.610.04.0DIN 127
M2222.535.911.04.0DIN 127
M2424.540.112.05.0DIN 127
M2727.544.812.05.0DIN 127
M3030.550.014.06.0DIN 127
M3636.560.016.07.0DIN 127

Video: What Are Spring Lock Washers Used For? in use

Video: What Are Spring Lock Washers Used For? in use

Third-party video, selected automatically for this topic. It is not produced by Engineering Hardware and is not a specification source — use the tables on this page for dimensional data.

Inside the plant

Manufactured in our own plant

This part is cold-formed, threaded, heat-treated and finished in-house. The stages below are where its class and finish are actually decided.

  1. Wire rod feeding into a cold heading machine
    01

    Cold heading

    Wire rod is drawn to size and cold-formed into blanks. Forming rather than cutting keeps the grain flow continuous around the head, which is where a bolt is most likely to fail.

    Head dimensions and under-head radius checked at set-up and per shift.

  2. Thread rolling machine producing bolt threads
    02

    Thread rolling

    Threads are rolled between hardened dies rather than cut. Rolled threads are stronger in fatigue than cut threads and hold pitch and flank angle far more consistently across a batch.

    Go / no-go ring gauges to ISO 965 tolerance class 6g.

  3. Baskets of bolts staged for heat treatment
    03

    Heat treatment

    Quench-and-temper brings carbon and alloy steel to the property class ordered — 8.8, 10.9 or 12.9 — with the furnace charge tracked so a finished lot can be traced back to it.

    Core hardness and tensile tested per lot to ISO 898-1.

  4. Zinc plated bolts in a treatment basket
    04

    Surface treatment

    Zinc, zinc-nickel, hot-dip galvanizing, black oxide, phosphate and Dacromet, selected against the service environment rather than against the price list.

    Coating thickness and neutral salt spray hours to ISO 9227.

Frequently Asked Questions

Do Spring Lock Washers actually stop bolts loosening?

Spring and serrated washers help maintain tension under light vibration, but for critical joints a prevailing-torque locking nut or adhesive is more reliable. Flat washers mainly spread load and protect the surface.

What material should Spring Lock Washers be for outdoor use?

For damp, coastal or chemical environments specify A4 (316) stainless or a suitably coated steel. For indoor or dry use, A2 (304) stainless or zinc-plated steel is normally adequate.

Are Spring Lock Washers made to a recognized standard?

Yes — they are manufactured to DIN 127, so dimensions are interchangeable between suppliers when you quote the standard on your order.

What are Spring Lock Washers used for?

Load distribution and anti-loosening under a bolt or nut. They are supplied to DIN 127.

Can I get a quote for Spring Lock Washers in the size and material I need?

Yes. Use the technical drawing and quote form on this page to set the size and options, then send the exact configuration to our team for pricing and lead time.