For spiral-wound metal gasket, GB/T 4622 is the governing document for the dimensions listed below. Mechanical and performance requirements for this part family are set by its own standards, not by the bolt and screw property-class documents.
GB/T 4622 — Scope
The table below lists the dimensions catalogued for spiral-wound metal gasket — gb/t 4622 / asme b16.20 (series 090) under GB/T 4622. The scope of GB/T 4622 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 GB/T 4622. Tolerances for this part are the limits shown against each dimension in the table.
Dimensions Specified by GB/T 4622
| Nominal pipe size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Thickness t (mm) | Winding material | Reference standard |
|---|---|---|---|---|---|
| DN15 | 22 | 42 | 4.5 | 304SS + flexible graphite | GB/T 4622 / ASME B16.20 |
| DN20 | 27 | 49 | 4.5 | 304SS + flexible graphite | GB/T 4622 / ASME B16.20 |
| DN25 | 34 | 59 | 4.5 | 304SS + flexible graphite | GB/T 4622 / ASME B16.20 |
| DN32 | 43 | 69 | 4.5 | 304SS + flexible graphite | GB/T 4622 / ASME B16.20 |
| DN40 | 49 | 75 | 4.5 | 304SS + flexible graphite | GB/T 4622 / ASME B16.20 |
| DN50 | 61 | 87 | 4.5 | 304SS + flexible graphite | GB/T 4622 / ASME B16.20 |
| DN65 | 77 | 109 | 4.5 | 304SS + flexible graphite | GB/T 4622 / ASME B16.20 |
| DN80 | 89 | 121 | 4.5 | 304SS + flexible graphite | GB/T 4622 / ASME B16.20 |
| DN100 | 115 | 149 | 4.5 | 304SS + flexible graphite | GB/T 4622 / ASME B16.20 |
| DN150 | 169 | 205 | 4.5 | 304SS + flexible graphite | GB/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.
When to Specify GB/T 4622
Choose GB/T 4622 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for spiral-wound metal gasket — gb/t 4622 / asme b16.20 (series 090).
Custom manufacturing · Made to drawing
Need a washer to this standard in a non-standard size?
Parts built to GB T 4622 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.


