A4 Stainless Steel Spiral-Wound Metal Gasket are supplied to GB/T 4622 / ASME B16.20. The grade provides superior, including marine and chloride environments and is largely non-magnetic; the practical service range is approx. -200 °C to +400 °C, subject to the property class and the joint. Property data, grade comparison and the full size table follow.
Why Choose A4 Stainless Steel for Spiral-Wound Metal Gasket — GB/T 4622 / ASME B16.20 (Series 090)
Specified for marine, coastal and chemical applications. For spiral-wound metal gasket — gb/t 4622 / asme b16.20 (series 090), this matters when superior, including marine and chloride environments is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80 |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C, subject to the property class and the joint |
| Corrosion characteristic | Superior, including marine and chloride environments |
Corrosion Behavior in Service
A4 (316) adds 2–3% molybdenum to the A2 (304) composition, which dramatically improves resistance to chloride-pitting corrosion. For Spiral-Wound Metal Gasket — GB/T 4622 / ASME B16.20 (Series 090) in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Galvanic & Galling Considerations
For stainless spiral-wound metal gasket — gb/t 4622 / asme b16.20 (series 090) the compatibility question is galvanic rather than galling: joined to aluminum or galvanized steel in wet service, stainless drives corrosion of the less-noble metal. Isolate with a coating, sleeve or non-conductive washer where the joint sees moisture. Note also that stainless is softer than hardened carbon steel, so where the part carries a wear or shear duty, check the load against the grade before substituting.
Using Stainless Fasteners in Aluminum
Expect the aluminum to corrode, not the fastener — stainless sits higher in the galvanic series, so the aluminum is the one that gives up material. A small fastener in a thick section spreads the loss over a large area and is usually fine; a large fastener in thin sheet concentrates it and is not. Keep water out of the joint, or isolate the two metals with a nylon or coated washer and a sealant.
Sizes of Spiral-Wound Metal Gasket — GB/T 4622 / ASME B16.20 (Series 090) Available in A4 Stainless Steel
| Nominal pipe size | Inner diameter d1 (mm) | Outer diameter d2 (mm) | Thickness t (mm) | Reference standard |
|---|---|---|---|---|
| DN15 | 22 | 42 | 4.5 | GB/T 4622 / ASME B16.20 |
| DN20 | 27 | 49 | 4.5 | GB/T 4622 / ASME B16.20 |
| DN25 | 34 | 59 | 4.5 | GB/T 4622 / ASME B16.20 |
| DN32 | 43 | 69 | 4.5 | GB/T 4622 / ASME B16.20 |
| DN40 | 49 | 75 | 4.5 | GB/T 4622 / ASME B16.20 |
| DN50 | 61 | 87 | 4.5 | GB/T 4622 / ASME B16.20 |
| DN65 | 77 | 109 | 4.5 | GB/T 4622 / ASME B16.20 |
| DN80 | 89 | 121 | 4.5 | GB/T 4622 / ASME B16.20 |
| DN100 | 115 | 149 | 4.5 | GB/T 4622 / ASME B16.20 |
| DN150 | 169 | 205 | 4.5 | GB/T 4622 / ASME B16.20 |
Dimensions are independent of the material: the table above lists the sizes supplied, and on this page every one of them is quoted in A4 Stainless Steel. The catalogue's default material column has been omitted here so it cannot be read as contradicting that.
Custom manufacturing · Made to drawing
Need this washer in a grade that is not listed?
A4 Stainless Steel is one of the grades the catalog describes. Bearing area is usually the reason for a special washer: a larger outside diameter to spread load into a softer material, or a thicker section to resist dishing. Made by stamping or punching.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
