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Washers · DIN 6340 · Application guide

What Are Heavy-Duty Washers for Clamping Fixtures Used For?

Typical applications, the industries that specify heavy-duty washers for clamping fixtures, and how to choose the right size, material and finish for the joint.

Heavy-Duty Washers for Clamping Fixtures are used for thick hardened washers for clamping devices and fixtures. They are manufactured to DIN 6340, and selection is driven by the nominal bolt size, the fit and tolerance the assembly requires, and the service environment.

Primary duty
Thick hardened washers for clamping devices and fixtures
Governing standard
DIN 6340
Nominal bolt size range
M6 to M30
Category
Washers

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

What Are Heavy-Duty Washers for Clamping Fixtures Used For? application image

The primary duty of Heavy-Duty Washers for Clamping Fixtures is thick hardened washers for clamping devices and fixtures. Below: the sectors that specify them in volume, the checklist used to select the right size and material for the application, installation notes, and the known limits of the type. Stocked across roughly M6 to M30, they cover general to heavy-duty work.

Typical Applications for Heavy-Duty Washers for Clamping Fixtures

The most common settings where these are specified:

  • Machine tools: clamps on T-slot tables.
  • Fixtures: repeated clamping.
  • Die sets: hardened bearing faces.
  • Presses: high-load clamping.

How to Specify Heavy-Duty Washers for Clamping Fixtures for Your Application

  • Size: Match the nominal size to the mating thread or hole. This product spans M6–M30; 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 6340. 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 Heavy-Duty Washers for Clamping Fixtures

  • 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 Heavy-Duty Washers for Clamping Fixtures 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 heavy-duty washers for clamping fixtures 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 M6 Heavy-Duty Washers for Clamping Fixtures to DIN 6340. Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.
Inner diameter d1 (mm)
6.4
Outer diameter d2 (mm)
17.0
Thickness h (mm)
3.0
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 6340)

SizeInner diameter d1 (mm)Outer diameter d2 (mm)Thickness h (mm)Reference standard
M66.417.03.0DIN 6340
M88.423.04.0DIN 6340
M1010.526.04.0DIN 6340
M1213.035.05.0DIN 6340
M1617.045.06.0DIN 6340
M2021.050.06.0DIN 6340
M2425.060.08.0DIN 6340
M3031.068.010.0DIN 6340
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

What are Heavy-Duty Washers for Clamping Fixtures used for?

Thick hardened washers for clamping devices and fixtures. They are supplied to DIN 6340.

Which industries use Heavy-Duty Washers for Clamping Fixtures?

They are commonly specified in die sets, presses and machine tools, among other sectors.

How do I choose the right size of Heavy-Duty Washers for Clamping Fixtures?

Match the nominal size to the mating thread or hole. This product is available from M6 to M30; the full dimension table on this page lists each size.

Do Heavy-Duty Washers for Clamping Fixtures 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.

Can I get a quote for Heavy-Duty Washers for Clamping Fixtures 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.