Stainless Steel · Fittings · ASTM A403 WP321
SS 321 Stainless Steel Fittings
In short: SS 321 fittings: butt-weld to ASTM A403 WP321 and forged to A182 F321, matching SS 321 pipe in hot process and exhaust systems.
- S32100
- UNS number
- 7.93
- density, g/cm³
- 3.1 / 3.2
- EN 10204 certificates
- 6
- SS 321 product forms
Why this combination
Why SS 321 in fittings
Elbows and tees in hot lines must be stabilised like the pipe; WP321 fittings keep the system uniform.
Weld with SS 347-type filler for stabilised weld metal.
Specification
How to specify SS 321 fittings
Butt-weld ½" – 48" (larger fabricated to order) in schedules matching the pipe; socket-weld and threaded ⅛" – 4" in Class 2000, 3000, 6000 and 9000
- Specification
- ASTM A403 WP321 (butt-weld); A182 F321 (forged)
- UNS
- S32100
- EN / W.Nr.
- 1.4541
- Butt-weld
- A403 WP321, ASME B16.9
- Forged
- A182 F321, ASME B16.11
Sizes and weights
SS 321 fittings sizes, weighed at 7.93 g/cm³
Other sizes on request. For general fittings information, such as manufacturing routes and end finishes, see the fittings guide.
Butt-weld ½" – 48" (larger fabricated to order) in schedules matching the pipe; socket-weld and threaded ⅛" – 4" in Class 2000, 3000, 6000 and 9000
Chemistry
SS 321 composition
- UNS
- S32100
- EN / W.Nr.
- 1.4541 · X6CrNiTi18-10
- Density
- 7.93 g/cm³
| Element | Limit, % | Why it matters |
|---|---|---|
| C | 0.08 max | |
| Mn | 2.00 max | |
| P | 0.045 max | |
| S | 0.030 max | |
| Si | 0.75 max | |
| Cr | 17.0 – 19.0 | |
| Ni | 9.0 – 12.0 | |
| Ti | 5×(C+N) – 0.70 | |
| N | 0.10 max |
Limits per ASTM A240; other product forms and specifications differ slightly. Your order's specification and edition govern.
Questions
About SS 321 fittings
Which fittings match SS 321 pipe?
A403 WP321 butt-weld and A182 F321 forged fittings.
Are SS 321 fittings available seamless?
Yes, as WP321-S in common sizes.
From enquiry to dispatch
How a SS 321 fittings order runs
- 01 EnquiryGrade, specification, size, quantity
- 02 ReviewChecked against your standard
- 03 InspectPMI, dimensions, TPI if required
- 04 CertifyEN 10204 3.1 / 3.2, heat traceable
- 05 ShipPacked and documented for the destination
Need SS 321 fittings?
Send size, quantity, specification and destination. We reply with availability, certificates and delivery.