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Washers · DIN 7603 Type A

DIN 7603 Aluminum Flat Sealing Washers Specification

Dimensional table, tolerance classes and the DIN / ISO / ASME parts that supersede or match this standard.

DIN 7603 specifies the dimensions and tolerances for aluminum flat sealing washers. The full dimensional table is reproduced below, followed by the DIN, ISO and ASME parts that match or supersede it.

Standard
DIN 7603
Product
Aluminum Flat Sealing Washers
Governing standards
DIN 7603 Type A

Equivalence between national standards is dimensional, not always metallurgical. Check the property class separately when substituting.

DIN 7603 Aluminum Flat Sealing Washers Specification reference image

Specification summary of DIN 7603 as applied to aluminum flat sealing washers: the dimensions the standard fixes, the full size range supplied, and the related designations commonly cross-referenced.

DIN 7603 — Scope

DIN 7603 specifies the dimensional requirements for aluminum flat sealing washers. Material, surface condition and any performance rating are set by separate documents specific to this part family — ISO 898-1 and ISO 898-2, which govern bolt and nut property classes, do not apply here.

Tolerance & Product Grades

Tolerances for aluminum flat sealing washers are given as limits on the individual dimensions in the table rather than as a fastener product grade. Where a general-tolerance class is cited on the drawing instead, it applies to the dimensions not otherwise toleranced.

Dimensions Specified by DIN 7603

For bolt sizePitch (mm)Inside diameter (mm)Outside diameter (mm)Thickness options (mm)MaterialReference standard
M81.08.211.41.0 / 1.5 / 2.0aluminumDIN 7603 Type A
M101.010.213.41.0 / 1.5 / 2.0aluminumDIN 7603 Type A
M121.512.215.91.0 / 1.5 / 2.0aluminumDIN 7603 Type A
M141.514.217.91.0 / 1.5 / 2.0aluminumDIN 7603 Type A
M161.516.219.91.0 / 1.5 / 2.0aluminumDIN 7603 Type A
M201.520.223.91.0 / 1.5 / 2.0aluminumDIN 7603 Type A
M301.530.335.91.0 / 1.5 / 2.0aluminumDIN 7603 Type A
M482.048.354.91.0 / 1.5 / 2.0aluminumDIN 7603 Type A

Equivalent Standards

Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Aluminum Flat Sealing Washers page. Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.

Companion Standards

DIN 7603 controls only the geometry of aluminum flat sealing washers. Surface finish is governed by separate finish standards (for example ISO 4042 for electroplating), and corrosion testing by ISO 9227 (neutral salt spray). Mechanical performance is set by the standards specific to this part family, not by ISO 898-1 or ISO 898-2, which apply to bolts, screws and nuts.

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 7603 Type A)

For bolt sizePitch (mm)Inside diameter (mm)Outside diameter (mm)Thickness options (mm)MaterialReference standard
M81.08.211.41.0 / 1.5 / 2.0aluminumDIN 7603 Type A
M101.010.213.41.0 / 1.5 / 2.0aluminumDIN 7603 Type A
M121.512.215.91.0 / 1.5 / 2.0aluminumDIN 7603 Type A
M141.514.217.91.0 / 1.5 / 2.0aluminumDIN 7603 Type A
M161.516.219.91.0 / 1.5 / 2.0aluminumDIN 7603 Type A
M201.520.223.91.0 / 1.5 / 2.0aluminumDIN 7603 Type A
M301.530.335.91.0 / 1.5 / 2.0aluminumDIN 7603 Type A
M482.048.354.91.0 / 1.5 / 2.0aluminumDIN 7603 Type A

Applications & Industries

Where Aluminum Flat Sealing Washers are used, and what decides the specification in each case. Stocked from M8 to M48 (nominal bolt size).

Industries that specify Aluminum Flat Sealing Washers

  • Hydraulic service Crush seals under banjo bolts, plugs and threaded fittings.
  • Fuel systems Soft-metal sealing at machined fitting faces.
  • Automotive maintenance Single-use sealing washers replaced during fluid service.
  • Pneumatic equipment Lightweight sealing at air and instrument connections.
  • Steel fabrication Spreading load under a head or nut and protecting the surface finish.
  • Machine building & OEM Setting bearing area on soft alloy, plastic and oversized holes.

Typical applications

  • crushing a flat aluminum ring between two machined faces
  • sealing a threaded fitting without an elastomer gasket
  • matching the inside and outside diameters to the fitting seat
  • replacing the washer after it has been compressed in service
  • maintaining bolt tension in a joint that settles
  • spreading clamp load over a soft or oversized bearing face

Service conditions to specify against

Marine and coastal
Available in A4 (316) stainless for chloride exposure — coastal structures, pool halls, water treatment and deck hardware, where A2 will eventually pit.
Sealed joints
Used where the fixing has to keep water or air out as well as hold — the elastomer, not the fastener, decides service life.
Hardness matters
Under a high-strength bolt a soft washer embeds into the joint and preload is lost — specify a hardened washer for structural bolting.

Where to use something else

  • Do not reuse a crushed washer or tighten it against a damaged sealing face; leakage is the usual result.

Full application guide: where Aluminum Flat Sealing Washers are used, how to specify them, and the cases they are wrong for

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

Which edition of DIN 7603 does this table follow?

The table reproduces the dimensions we supply aluminum flat sealing washers to. We do not publish an edition year against it, so where the edition is contractually significant, cite the edition you require on the enquiry and we will confirm it against the table before quoting.

What does DIN 7603 specify for Aluminum Flat Sealing Washers?

DIN 7603 specifies the dimensions and tolerances of aluminum flat sealing washers. Material and property class are governed by separate standards in the same family.

Does DIN 7603 specify the mechanical strength?

No. DIN 7603 controls the dimensional requirements for aluminum flat sealing washers. Mechanical performance is set by the standards specific to this part family — ISO 898-1 and ISO 898-2 apply to bolts, screws and nuts and do not cover this product.

Can I substitute DIN 7603 for the corresponding DIN standard on a drawing?

On modern drawings the ISO standard is the master reference; the older DIN equivalent is a cross-reference. For most dimensional purposes the parts are interchangeable, but check tolerance grades and the head height — these are the most common points of divergence.

How do I request a quotation?

Use the technical drawing on this page to pick the exact configuration, then submit it with the quote form. We respond within one business day.