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Washers · GB/T 4622 / ASME B16.20

ASME B16.20 Spiral-Wound Metal Gasket Specification

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

ASME B16.20 specifies the dimensions and tolerances for spiral-wound metal gasket. The full dimensional table is reproduced below, followed by the DIN, ISO and ASME parts that match or supersede it.

Standard
ASME B16.20
Product
Spiral-Wound Metal Gasket — GB/T 4622 / ASME B16.20 (Series 090)
Governing standards
GB/T 4622 / ASME B16.20

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

ASME B16.20 Spiral-Wound Metal Gasket Specification reference image

Specification summary of ASME B16.20 as applied to spiral-wound metal gasket: the dimensions the standard fixes, the full size range supplied, and the related designations commonly cross-referenced.

ASME B16.20 — Scope

The table below lists the dimensions catalogued for spiral-wound metal gasket — gb/t 4622 / asme b16.20 (series 090) under ASME B16.20. The scope of ASME B16.20 itself is not summarised here — where a figure matters, confirm it against the published document.

Tolerance & Product Grades

Product grade is a concept from dimensional fastener standards and does not apply to ASME B16.20. Tolerances for this part are the limits shown against each dimension in the table.

Dimensions Specified by ASME B16.20

Nominal pipe sizeInner diameter d1 (mm)Outer diameter d2 (mm)Thickness t (mm)Winding materialReference standard
DN1522424.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN2027494.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN2534594.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN3243694.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN4049754.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN5061874.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN65771094.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN80891214.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN1001151494.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN1501692054.5304SS + flexible graphiteGB/T 4622 / ASME B16.20

Equivalent Standards

Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Spiral-Wound Metal Gasket — GB/T 4622 / ASME B16.20 (Series 090) page.

Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.

Companion Standards

A complete specification for spiral-wound metal gasket — gb/t 4622 / asme b16.20 (series 090) normally cites several documents: one for the geometry, one for the material or mechanical properties, and one for the finish. ASME B16.20 is one of them, not all of them.

Custom manufacturing · Made to drawing

Need a washer to this standard in a non-standard size?

Parts built to ASME B16 20 are already in the catalog, so a special is usually a variation on existing tooling rather than a new design — which is what keeps the cost down. 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 DN15 Spiral-Wound Metal Gasket — GB/T 4622 / ASME B16.20 (Series 090) to GB/T 4622 / ASME B16.20. Side view and top view, drawn to the dimensions in the table below and redrawn for any size selected.
Inner diameter d1 (mm)
22
Outer diameter d2 (mm)
42
Thickness t (mm)
4.5
Winding material
304SS + flexible graphite
Opens a short step to confirm the exact specification before you enter contact details.

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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.

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Specification
Business Information

Dimensions & Specifications (GB/T 4622 / ASME B16.20)

Nominal pipe sizeInner diameter d1 (mm)Outer diameter d2 (mm)Thickness t (mm)Winding materialReference standard
DN1522424.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN2027494.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN2534594.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN3243694.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN4049754.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN5061874.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN65771094.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN80891214.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN1001151494.5304SS + flexible graphiteGB/T 4622 / ASME B16.20
DN1501692054.5304SS + flexible graphiteGB/T 4622 / ASME B16.20

Applications & Industries

Spiral-Wound Metal Gasket are bought for a small number of well-defined jobs. These are the ones we ship them for. Stocked from DN15 to DN150 (size designation).

Industries that specify Spiral-Wound Metal Gasket

  • Rotating & vibrating plant Spring, tooth and wedge types that maintain or lock bolt tension.
  • 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.
  • Timber & construction Large-diameter washers that stop pull-through in softer material.

Typical applications

  • maintaining bolt tension in a joint that settles
  • spreading clamp load over a soft or oversized bearing face
  • protecting a painted or plated surface under a turned nut

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.
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.

Full application guide: where Spiral-Wound Metal Gasket are used, how to specify them, and the cases they are wrong for

Video: ASME B16.20 Spiral-Wound Metal Gasket Specification

Metallic Gaskets for pipe Flanges | ASME B16.20 | Content tour and Gasket details

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

Can I substitute ASME B16.20 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.

Which edition of ASME B16.20 does this table follow?

The table reproduces the dimensions we supply spiral-wound metal gasket — gb/t 4622 / asme b16.20 (series 090) 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.

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.