Stainless Steel Fittings
SS Pipe Fittings A403 321H
SS Pipe Fittings A403 321H Supplier, ASTM A403 WP321H Stainless Steel Fittings, Reliable Pipes & Tubes.
Reliable Pipes & Tubes – Leading SS Pipe Fittings A403 321H Supplier
Reliable Pipes & Tubes is a leading supplier, stockholder, and exporter of high-grade SS Pipe Fittings A403 321H. SS Pipe Fittings A403 321H refers to ASTM A403 standard covering wrought titanium-stabilized austenitic stainless steel piping fittings for pressure service in the WP321H grade. The high carbon content in SS Pipe Fittings A403 321H (ranging from 0.04% to 0.10% carbon) provides superior high-temperature strength and creep resistance, making them ideal for long-term elevated thermal applications.
The SS Pipe Fittings A403 321H are designed for forged steel pipe fittings and can be used in many critical engineering fields including chemical processing, power plants, thermal reactors, refineries, heat exchangers, boiler tubes, and other severe heat-exposed systems. Material under ASTM A403 is named as WP Grade, and for each WP grade stainless steel, several categories of pipe fittings are included to indicate that a seamless or welded structure is used.
We offer a comprehensive range of SS Pipe Fittings A403 321H from 1/2" NB to 48" NB in various schedules to meet custom applications. Every SS Pipe Fittings A403 321H supplied by Reliable Pipes & Tubes undergoes rigorous testing including tensile testing, chemical analysis, and visual inspection to ensure optimal quality and structural integrity.
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What is SS Pipe Fittings A403 321H?
SS Pipe Fittings A403 321H refers to ASTM A403 standard for wrought austenitic stainless steel piping fittings, specifically the WP321H high-carbon variant. The SS Pipe Fittings A403 321H are specifically designed for forged steel pipe fittings; cast pipe fittings are not suitable under this standard. The key advantage of SS Pipe Fittings A403 321H is the combination of titanium stabilization with a controlled higher carbon content (0.04–0.10%). Titanium binds with carbon to form stable titanium carbides, protecting grain boundaries from chromium depletion and ensuring robust resistance to intergranular corrosion at temperatures where standard grades sensitize. All SS Pipe Fittings A403 321H should be supplied in heat treated condition and all welding work should be done before heat treatment.
SS Pipe Fittings A403 321H Quick Details
| Parameter |
Details |
| Company Name | Reliable Pipes & Tubes |
| Country/Region | India |
| FOB Price | US $2200 - $7000 / Metric Ton |
| Port | Nhava Sheva Port, Mumbai |
| Main Products | Pipe Fittings, Elbows, Tees, Reducers, Caps, Flanges |
| Certification | ISO 9001, ISO 14001 & OHSAS 18001 |
SS Pipe Fittings A403 321H Specifications
| Specification Heading |
Details |
| Specification | ASTM A403 / ASME SA403 |
| Grade | WP321H |
| UNS Number | S32109 |
| DIN / EN | 1.4878 |
| Types | Seamless or Welded |
| Dimension Range | 1/2" NB to 48" NB |
| Wall Thickness Range | Schedule 10S, Schedule 40S, Schedule 80S, Schedule 160S, Schedule XXS |
| Dimension Standards | ASME B16.9, ASME B16.11, MSS SP-43, MSS SP-79, MSS SP-95, MSS SP-97, BS3799, BS21, ISO 4144 |
| Fitting Types | Elbow, Tee, Cap, Reducer, Coupling, Nipple, Bend, Olets, Stubend, Cross |
| Surface Finish | Pickled, Annealed & Pickled, Sand Blasting, Passivated |
| Ends | Plain Ends, Beveled Ends, Threaded Ends |
| Packaging | Wooden Pallet / Wooden Box / Plastic Cloth Wraps / Plastic End Caps |
| Material Test Certificate | EN10204 3.1, 3.2 / Laboratory Test Certificate from NABL Approved Lab. / Under Third Party Inspection Agency like SGS, TUV, DNV, LLOYDS, ABS etc. |
| Equivalent Standards | GOST, AWWA, BS, SS, KS, AISI, JIS, GB, IS, ISO, SAE, DIN, NFA, API, ASTM, CSA, ANSI, EN, UNI |
Referred Standards of SS Pipe Fittings A403 321H
| Standard |
Description |
| ASTM A182/A182M | Forged or rolled alloy steel pipe flanges, forged fittings and valves and parts for high temperature service |
| ASTM A403/A403M | Standard Specification for Wrought Austenitic Stainless Steel Piping Fittings |
| ASTM A815/A815M | Wrought ferritic, ferritic/austenitic and martensitic stainless steel piping fittings |
| AS 2129 | Flanges for pipes, valves and fittings |
| ANSI/ASME B1.20.1 | Pipe threads, general purpose (inch) |
| ANSI B16.5 | Steel pipe flanges and flanged fittings |
| ANSI B16.9 | Factory-made wrought steel butt-welding fittings |
| ANSI B16.11 | Forged steel fittings socket-welding and threaded |
| ANSI B16.25 | Butt-welding ends |
| MSS SP-43 | Wrought stainless steel butt-welding fittings |
| MSS SP-95 | Swage(d) Nipples and Bull Plugs |
| BS 21 | Threading |
| ISO 4144 | Stainless steel fittings threaded to ISO 7-1 |
| BS 3799 | Specification for Steel pipe fittings, screwed and Socket-welding for the petroleum industry |
| ASME B16.28 | Wrought Steel Buttwelding Short Radius Elbows and Returns |
| AWS A5.4, A5.9, A5.11, A5.14 | Welding Consumables Standards |
Chemical Composition of SS Pipe Fittings A403 321H
| Element |
Min (%) |
Max (%) |
| Carbon (C) | 0.04 | 0.10 |
| Manganese (Mn) | - | 2.0 |
| Silicon (Si) | - | 0.75 |
| Phosphorus (P) | - | 0.045 |
| Sulfur (S) | - | 0.03 |
| Chromium (Cr) | 17.0 | 19.0 |
| Nickel (Ni) | 9.0 | 12.0 |
| Titanium (Ti) | 4 x C | 0.60 |
* Note: The key characteristic of SS Pipe Fittings A403 321H is the titanium-stabilized high-carbon content (0.04–0.10%) for superior elevated temperature properties.
Mechanical Properties of SS Pipe Fittings A403 321H
| Property |
Value |
| Density | 8.0 g/cm3 |
| Melting Point | 1454 °C (2650 °F) |
| Tensile Strength, min | 515 MPa (75 ksi) |
| Yield Strength 0.2% Offset, min | 205 MPa (30 ksi) |
| Elongation, min % | 35% |
| Hardness Brinell (HB), max | 217 |
Equivalent Grades For SS Pipe Fittings A403 321H
| STANDARD |
WERKSTOFF NR. |
UNS |
JIS |
BS |
EURONORM / EN |
| WP321H |
1.4878 |
S32109 |
SUS 321H |
321S51 |
X10CrNiTi18-10 |
* Note: These comparisons are approximate only. If exact equivalents are needed original specifications must be consulted.
SS Pipe Fittings A403 321H Dimensions
1. SS Pipe Fittings A403 321H Elbows and Returns Dimensions
| Nominal Pipe Size (inches) |
Outside Diameter (mm) |
Outside Diameter (inches) |
90° Elbows |
45° Elbows |
180° Returns |
| Long Radius (inches) |
Short Radius (inches) |
Long Radius (inches) |
Center to Center (inches) |
Back to Face (inches) |
| 1/2 | 21.3 | 0.840 | 1 1/2 | - | 5/8 | 3 | 1 7/8 |
| 3/4 | 26.7 | 1.050 | 1 1/8 | - | 7/16 | 2 1/4 | 1 11/16 |
| 1 | 33.4 | 1.315 | 1 1/2 | 1 | 7/8 | 3 | 2 3/16 |
| 1 1/4 | 42.2 | 1.660 | 1 7/8 | 1 1/4 | 1 | 3 3/4 | 2 7/8 |
| 1 1/2 | 48.3 | 1.900 | 2 1/4 | 1 1/2 | 1 1/8 | 4 1/2 | 3 1/4 |
| 2 | 60.3 | 2.375 | 3 | 2 | 1 3/8 | 6 | 4 3/16 |
| 2 1/2 | 73.0 | 2.875 | 3 3/4 | 2 1/2 | 1 3/4 | 7 1/2 | 5 3/16 |
| 3 | 88.9 | 3.500 | 4 1/2 | 3 | 2 | 9 | 6 1/4 |
| 3 1/2 | 101.6 | 4.000 | 5 1/4 | 3 1/2 | 2 1/4 | 10 1/2 | 7 1/4 |
| 4 | 114.3 | 4.500 | 6 | 4 | 2 1/2 | 12 | 8 1/4 |
| 5 | 141.3 | 5.563 | 7 1/2 | 5 | 3 1/8 | 15 | 10 5/16 |
| 6 | 168.3 | 6.625 | 9 | 6 | 3 3/4 | 18 | 12 5/16 |
| 8 | 219.1 | 8.625 | 12 | 8 | 5 | 24 | 16 5/16 |
| 10 | 273.1 | 10.750 | 15 | 10 | 6 1/4 | 30 | 20 3/8 |
| 12 | 323.9 | 12.750 | 18 | 12 | 7 1/2 | 36 | 24 3/8 |
2. SS Pipe Fittings A403 321H Tees, Caps, Stub Ends and Straight Crosses Dimensions
| Nominal Pipe Size (inches) |
Outside Diameter (mm) |
Outside Diameter (inches) |
Caps |
Straight Tees |
Straight Crosses |
Stub Ends |
| Length (inches) |
Center to End (inches) |
Center to End (inches) |
Lap Diameter (inches) |
Long Length (inches) |
Short Length (inches) |
| 1/2 | 21.3 | 0.840 | 1 | 1 | - | 1 3/8 | 3 | 2 |
| 3/4 | 26.7 | 1.050 | 1 | 1 1/8 | - | 1 11/16 | 3 | 2 |
| 1 | 33.4 | 1.315 | 1 1/2 | 1 1/2 | 1 1/2 | 2 | 4 | 2 |
| 1 1/4 | 42.2 | 1.660 | 1 1/2 | 1 7/8 | 1 7/8 | 2 1/2 | 4 | 2 |
| 1 1/2 | 48.3 | 1.900 | 1 1/2 | 2 1/4 | 2 1/4 | 2 7/8 | 4 | 2 |
| 2 | 60.3 | 2.375 | 1 1/2 | 2 1/2 | 2 1/2 | 3 5/8 | 6 | 2 1/2 |
| 2 1/2 | 73.0 | 2.875 | 1 1/2 | 3 | 3 | 4 1/8 | 6 | 2 1/2 |
| 3 | 88.9 | 3.500 | 2 | 3 3/8 | 3 3/8 | 5 | 6 | 2 1/2 |
| 3 1/2 | 101.6 | 4.000 | 2 1/2 | 3 3/4 | 3 3/4 | 5 1/2 | 6 | 3 |
| 4 | 114.3 | 4.500 | 2 1/2 | 4 1/8 | 4 1/8 | 6 1/16 | 6 | 3 |
| 5 | 141.3 | 5.563 | 3 | 4 7/8 | 4 7/8 | 7 5/16 | 8 | 3 |
| 6 | 168.3 | 6.625 | 3 1/2 | 5 5/8 | 5 5/8 | 8 1/2 | 8 | 3 1/2 |
| 8 | 219.1 | 8.625 | 4 | 7 | 7 | 10 5/8 | 8 | 4 |
| 10 | 273.1 | 10.750 | 5 | 8 1/2 | 8 1/2 | 12 3/4 | 10 | 5 |
| 12 | 323.9 | 12.750 | 6 | 10 | 10 | 15 | 10 | 6 |
3. SS Pipe Fittings A403 321H Reducers Dimensions
| Nominal Pipe Size (inches) |
Outside Diameter (mm) |
Outside Diameter (inches) |
Reduced to (inches) |
Concentric & Eccentric Length (inches) |
| 1/2 | 21.3 | 0.840 | 1/4, 3/8 | 1 1/2 |
| 3/4 | 26.7 | 1.050 | 3/8, 1/2 | 2 |
| 1 | 33.4 | 1.315 | 3/8, 1/2, 3/4 | 2 |
| 1 1/4 | 42.2 | 1.660 | 1/2, 3/4, 1 | 2 |
| 1 1/2 | 48.3 | 1.900 | 1/2, 3/4, 1, 1 1/4 | 2 1/2 |
| 2 | 60.3 | 2.375 | 3/4, 1, 1 1/4, 1 1/2 | 3 |
| 2 1/2 | 73.0 | 2.875 | 1, 1 1/4, 1 1/2, 2 | 3 1/2 |
| 3 | 88.9 | 3.500 | 1, 1 1/2, 2, 2 1/2 | 3 1/2 |
| 3 1/2 | 101.6 | 4.000 | 1 1/4, 1 1/2, 2, 2 1/2, 3 | 4 |
| 4 | 114.3 | 4.500 | 1 1/2, 2, 2 1/2, 3, 3 1/2 | 4 |
| 5 | 141.3 | 5.563 | 2, 2 1/2, 3, 3 1/2, 4 | 5 |
| 6 | 168.3 | 6.625 | 2 1/2, 3, 3 1/2, 4, 5 | 5 1/2 |
| 8 | 219.1 | 8.625 | 3, 3 1/2, 4, 5, 6 | 6 |
| 10 | 273.1 | 10.750 | 4, 5, 6, 8 | 7 |
| 12 | 323.9 | 12.750 | 5, 6, 8, 10 | 8 |
Fitting Types for SS Pipe Fittings A403 321H
| Fitting Type |
Description |
| Elbow | SS Pipe Fittings A403 321H – 45°, 90°, 180° elbows, including 3D/5D/10D bends for directional changes |
| Tee | SS Pipe Fittings A403 321H – Equal and reducing/unequal tees for branching connections |
| Cap | SS Pipe Fittings A403 321H – End caps to safely close pipe ends |
| Reducer | SS Pipe Fittings A403 321H – Concentric and eccentric reducers for size transition |
| Coupling | SS Pipe Fittings A403 321H – Couplings for joining pipes of the same size |
| Nipple | SS Pipe Fittings A403 321H – Barrel nipples, reducing nipples, swage nipples |
| Bend | SS Pipe Fittings A403 321H – Long radius, short radius, and customized piggable bends |
| Olets | SS Pipe Fittings A403 321H – Weldolets, sockolets, threadolets, and branch outlets |
SS Pipe Fittings A403 321H ASTM A403 Standard Scope
The ASTM A403 standard for SS Pipe Fittings A403 321H includes several grades of austenitic stainless steel alloys, and uses the WP or CR prefix to mark the grade of steel. Steel for SS Pipe Fittings A403 321H should be smelted using one of the following methods:
- Electric furnace (with separate refining optional)
- Vacuum furnace
- One of the former followed by vacuum remelting or electroslag consumable electrode remelting
- If secondary melting is used, the furnace number refers to all steel ingots remelted with one smelting furnace number
The forming or forging operation for SS Pipe Fittings A403 321H may be performed by hammer forging, press forging, perforating, extrusion, upsetting, rolling, bending, welding or machining, or two or more methods at the same time. All SS Pipe Fittings A403 321H should be supplied in heat treated condition and all welding work should be done before heat treatment.
Surface Finish Requirements for SS Pipe Fittings A403 321H
- Surface crack (fish scales) deeper than 1/64 inch (0.4 mm) should be removed from SS Pipe Fittings A403 321H
- Mechanical flaws deeper than 1/16 inch (1.6 mm) should be removed from SS Pipe Fittings A403 321H
- SS Pipe Fittings A403 321H shall not have a surface discontinuity deeper than 5% of the specified nominal wall thickness
- SS Pipe Fittings A403 321H shall have a good machined surface and shall be free of scale and passivated
Repair by Welding Allowance for SS Pipe Fittings A403 321H
- When the defect depth exceeds 33 1/3% of the nominal wall thickness in SS Pipe Fittings A403 321H, weld repair is not allowed
- When the defect area exceeds 10% of the surface area of SS Pipe Fittings A403 321H, weld repair is not allowed
- Unacceptable defects should be removed by mechanical means or by thermal cutting or gouging methods
- SS Pipe Fittings A403 321H shall be free of scale and shall be passivated
SS Pipe Fittings A403 321H Stock List
- SS Pipe Fittings A403 321H – 90 Deg Elbow (Long / Short Radius)
- SS Pipe Fittings A403 321H – 45 Deg Elbow
- SS Pipe Fittings A403 321H – 180 Deg Elbow (Return Bend)
- SS Pipe Fittings A403 321H – Equal Tee
- SS Pipe Fittings A403 321H – Reducing Tee
- SS Pipe Fittings A403 321H – Concentric Reducer
- SS Pipe Fittings A403 321H – Eccentric Reducer
- SS Pipe Fittings A403 321H – End Cap / Pipe Cap
- SS Pipe Fittings A403 321H – Stubend (Long / Short Length)
- SS Pipe Fittings A403 321H – Barrel / Swage / Reducing Nipple
- SS Pipe Fittings A403 321H – 3D, 5D, 10D Piggable Bend
- SS Pipe Fittings A403 321H – Weldolets / Sockolets / Threadolets
Testing Requirements for SS Pipe Fittings A403 321H
| Test Type |
Details |
| Tensile Test | Longitudinal or transverse cut specimens; properties shall comply with tensile requirements per A370 methods |
| Chemical Analysis | Each cast or furnace steel chemical composition shall be determined and comply with WP321H requirements |
| Visual Inspection | All SS Pipe Fittings A403 321H shall be visually inspected for surface discontinuities |
| Liquid Penetrant Test | As per ASTM E165 Practice for Liquid Penetrant Examination for General Industry |
| Grain Size Test | As per ASTM E112 Test Methods for Determining Average Grain Size |
| Radiography Testing | 100% Radiography Tested for welded fittings where specified |
| PMI Testing | Positive Material Identification for SS Pipe Fittings A403 321H |
| Hydrostatic Test | As required per applicable standards |
| Hardness Test | Rockwell and Brinell hardness testing as required |
SS Pipe Fittings A403 321H Price List
| Product Description |
Price (FOB) |
| SS Pipe Fittings A403 321H – Elbow | US $2.50 - 22.00 / Piece |
| SS Pipe Fittings A403 321H – Tee | US $3.50 - 28.00 / Piece |
| SS Pipe Fittings A403 321H – Reducer | US $3.20 - 25.00 / Piece |
| SS Pipe Fittings A403 321H – Cap | US $2.00 - 16.00 / Piece |
| SS Pipe Fittings A403 321H – Coupling | US $1.30 - 11.00 / Piece |
| SS Pipe Fittings A403 321H – Bend | US $6.00 - 72.00 / Piece |
| SS Pipe Fittings A403 321H – Per Ton | US $2700 - 6000 / Ton |
Packaging and Sea Transportation Protection
At Reliable Pipes & Tubes, packaging is processed with standard anti-rust measures and sea transportation security rules. We ensure that your SS Pipe Fittings A403 321H reach safely and in perfect condition via the following packaging modes:
- Bundle packing with steel strips
- Crate packing (wooden cases)
- Naked packing
- End protection with plastic caps or wooden protectors