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Washers · DIN 988 · Application guide

What Are Shim Rings (Support Washers) Used For?

Typical applications, the industries that specify shim rings (support washers), and how to choose the right size, material and finish for the joint.

Shim Rings (Support Washers) are used for setting and adjusting an axial gap or preload by stacking calibrated thicknesses. They are manufactured to DIN 988, and selection is driven by the nominal diameter, the fit and tolerance the assembly requires, and the service environment.

Primary duty
Setting and adjusting an axial gap or preload by stacking calibrated thicknesses
Governing standard
DIN 988
Nominal diameter range
3 mm to 12 mm
Category
Washers

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

What Are Shim Rings (Support Washers) Used For? application image

Application guide for Shim Rings (Support Washers) to DIN 988. The core duty of the type is setting and adjusting an axial gap or preload by stacking calibrated thicknesses. The typical industries, the how-to-specify checklist, assembly practice and the exclusion cases are set out below. Stocked across roughly 3 mm to 12 mm, they cover general to heavy-duty work.

Typical Applications for Shim Rings (Support Washers)

The most common settings where these are specified:

  • 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.
  • Fabrication & metalwork: bench and on-site assembly of steel frames, enclosures and weldments.
  • Bolted structural joints: spreading load over soft or oversized holes and protecting the surface.

How to Specify Shim Rings (Support Washers) for Your Application

  • Size: Match the nominal size to the mating thread or hole. This product spans 3 mm–12 mm; 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 988. 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 Shim Rings (Support 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 Shim Rings (Support 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.

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.

Sends the selected values to the quote form below.

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The form below follows the current technical drawing configuration. Change the drawing values above and the request details update automatically.

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Specification
Business Information

Dimensions & Specifications (DIN 988)

SizeInner diameter d1 (mm)Outer diameter d2 (mm)Thickness s (mm)Reference standardNotes
3360.1DIN 988Also 0.15, 0.2 thickness
4480.1DIN 988Also 0.15, 0.2, 0.3 thickness
55100.1DIN 988Also 0.15, 0.2, 0.3 thickness
66120.1DIN 988Also 0.15, 0.2, 0.3, 0.5, 1, 1.2 thickness
77130.1DIN 988Also 0.15, 0.2, 0.3, 0.5, 1, 1.2, 1.4 thickness
88140.1DIN 988Also 0.15, 0.2, 0.3, 0.5, 1, 1.2, 1.5 thickness
99150.1DIN 988Thickness range 0.1-1.6
1010160.1DIN 988Thickness range 0.1-1.8
1111170.1DIN 988Thickness range 0.1-1.8
1212180.1DIN 988Thickness range 0.1-1.8
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

Are Shim Rings (Support Washers) made to a recognized standard?

Yes — they are manufactured to DIN 988, so dimensions are interchangeable between suppliers when you quote the standard on your order.

What are Shim Rings (Support Washers) used for?

Setting and adjusting an axial gap or preload by stacking calibrated thicknesses. They are supplied to DIN 988.

Which industries use Shim Rings (Support Washers)?

They are commonly specified in bolted structural joints, vibration applications and timber & soft materials, among other sectors.

How do I choose the right size of Shim Rings (Support Washers)?

Match the nominal size to the mating thread or hole. This product is available from 3 mm to 12 mm; the full dimension table on this page lists each size.

Can I get a quote for Shim Rings (Support 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.