Buy SS 321 spiral wound gaskets direct from Ningbo Kaxite Sealing Materials Co., Ltd., a China-based manufacturer and exporter. SS 321 / UNS S32100 is a basic austenitic 18/8 stainless steel (Grade 304 base) stabilized by a titanium addition. The titanium stabilizes the alloy against intergranular corrosion after exposure to the chromium carbide precipitation range of 427–816°C (800–1500°F). SS 321 spiral wound gasket has higher creep and stress rupture properties than 304 and 304L gaskets, and also possesses good low-temperature toughness, making it the grade of choice for service up to about 900°C.
This page is written for procurement engineers, MRO buyers, aerospace and petrochemical project sourcing teams and EPC contractors who need a reliable SS 321 spiral wound gasket manufacturer. Whether you are comparing quotes, verifying material certificates or scheduling a bulk delivery for a high-temperature or intergranular-corrosion-sensitive project, the sections below cover the technical facts and commercial terms you need to place a firm order.
Ti addition stabilizes SS 321 against intergranular corrosion in the chromium carbide precipitation range of 427–816°C.
Basic austenitic 18/8 steel equivalent to Grade 304 in the annealed condition, superior in the 425–900°C service range.
Grade of choice for applications up to about 900°C, with high creep and stress rupture properties above 304 and 304L.
Custom sizes, non-standard dimensions, OEM marking and private-label packaging. MOQ 10 pcs, lead time 7–30 days.
SS 321 spiral wound gasket is made of SS 321 steel V-shape tape and winding with soft filler such as graphite and PTFE. This gasket has good general corrosion resistance and has excellent resistance to intergranular corrosion after exposure to temperatures in the chromium carbide precipitation range of 800–1500°F (427–816°C). SS 321 spiral wound gasket has higher creep and stress rupture properties than alloys 304 and 304L gaskets. It also possesses good low temperature toughness.
Stainless Steel 321 is a basic austenitic 18/8 steel (Grade 304) stabilised by Titanium (321) addition. SS 321 is used because they are not sensitive to intergranular corrosion after heating within the carbide precipitation range of 425–850°C. Stainless Steel 321 is the grade of choice for applications in the temperature range of up to about 900°C, combining high strength, resistance to scaling and phase stability with resistance to subsequent aqueous corrosion.
SS 321 is equivalent to Grade 304 in the annealed condition, and superior if a weldment in these grades has not been post-weld annealed or if the application involves service in the 425–900°C range. Subject to pitting and crevice corrosion in warm chloride environments, and to stress corrosion cracking above about 60°C. Considered resistant to potable water with up to about 200 mg/L chlorides at ambient temperatures, reducing to about 150 mg/L at 60°C.
| Element | N | Cr | Ni | C | Mn | Si | S | Ti |
|---|---|---|---|---|---|---|---|---|
| Typical value (%) | ≤0.10 | 17–19 | 9–12 | ≤0.08 | ≤2 | ≤1 | ≤0.03 | ≤0.70 |
For a specific heat analysis, request the material certificate with your order. Composition and mechanical values will be confirmed against the mill certificate before shipment.
The choice of winding material is driven by the process temperature, the risk of intergranular corrosion and the required creep strength. Use the comparison below as a starting point, then send the exact medium and operating temperature for confirmation.
| Property | SS 321 | SS 304 | SS 304L | SS 347 |
|---|---|---|---|---|
| Stabilizing element | Titanium | None | None | Niobium + tantalum |
| Carbide precipitation range | 427–816°C | Susceptible | Susceptible | 427–816°C |
| Intergranular corrosion resistance | Excellent | Limited in range | Limited in range | Excellent |
| Creep and stress rupture | Higher than 304/304L | Baseline | Slightly lower than 304 | Higher than 321 |
| High-temperature service | up to ~900°C | up to ~800°C | up to ~425°C | up to ~900°C |
| Typical gasket service | Aircraft exhaust, heat exchangers, mineral processing | General chemical, food | Welded general chemical | Refinery, polythionic acid service |
SS 321 spiral wound gaskets are used across high-temperature and oxidizing service where the flange joint must resist intergranular corrosion and creep rupture.
High-temperature exhaust flanges where Ti stabilization prevents intergranular corrosion in the carbide precipitation range.
Expansion joint flanges in high-temperature ducting and exhaust systems where creep strength matters.
Bellows and flexible element flanges where low-temperature toughness and high-temperature stability are both required.
Heating element and radiant tube flanges operating continuously in the 425–900°C range.
Shell and tube heat exchanger flanges in high-temperature oxidizing service.
Kiln, calciner and mineral processing flanges where SS 321 resistance to scaling and phase stability is required.
The winding alloy is only one half of the gasket. The filler must also be compatible with the process medium and operating temperature. For SS 321 the standard fillers are graphite and PTFE, with other options quoted on request.
High-temperature sealing performance for steam, hydrocarbon and high-temperature mineral processing. Preferred when the operating temperature is above the PTFE service envelope and the medium is compatible with graphite.
Excellent chemical resistance against most acids, alkalis, organic acids, inorganic acids and solvents. Preferred for chemical, pickling, acid and low-temperature service when the gasket is paired with an SS 321 winding.
If your service is high-temperature, oxidizing or chloride-bearing, send the chloride concentration, operating temperature and pressure so we can confirm the correct filler and winding combination.
Send the following five items with your enquiry. If you already have a flange drawing or an existing gasket sample, attach it and we will match it directly. Our sales engineers reply with a firm unit price, lead time and available samples.
NPS, DN or specific inner and outer diameters for non-standard joints.
Class 150, 300, 600, 900, 1500, 2500 or PN10 to PN250, plus the flange standard such as ASME B16.5 or EN 1092.
Graphite or PTFE as standard; other fillers quoted on request depending on the medium and temperature.
Carbon steel painted as standard; SS 304, SS 316 or SS 321 available for corrosive environments. Specify private-label or OEM marking if required.
Order quantity and destination port so we can quote FOB, CIF or freight-inclusive pricing. MOQ 10 pieces.
Send your flange standard, nominal pipe size, pressure class, filler, inner and outer ring material and quantity. Our sales engineers reply with a firm unit price, lead time and available samples. For urgent aerospace, heat exchanger or high-temperature mineral processing requirements, contact us by phone or WhatsApp.
Address
No 432 Zhenhai Middle Road, Luotuo Street, Zhenhai District, Ningbo City, Zhejiang China
