What Are Stainless Steel 304 Buttweld Fittings?
Stainless Steel 304 Buttweld Fittings are pipe connecting components manufactured from UNS S30400 austenitic stainless steel — the industry's most widely used "18/8" alloy (18% chromium, 8% nickel). A butt-weld joint is formed by welding the bevelled pipe end directly to the fitting end, creating a seamless, flush, and fully pressure-rated connection.
These fittings provide excellent corrosion resistance, excellent weldability, and adherence to world-wide piping codes, as a solution-annealed material provided under ASTM A403 WP304, and are therefore the most commonly used in chemical, food, pharmaceutical, oil and gas, and power generation pipelines around the globe.
- Excellent Corrosion Resistance — Resists oxidation and a wide range of atmospheric and chemical agents.
- High Strength — 515 MPa tensile strength; operates up to 870°C.
- Hygienic Surface — Non-porous; ideal for food, beverage, and pharma lines.
- Superior Weldability — Easily welded without loss of structural integrity.
- Global Code Compliant — ASME B16.9, MSS-SP-43, NACE MR01-75.
- High Temperature Performance — Rated for service up to 870°C (1600°F); maintains structural integrity in heat exchangers, boilers, fired heaters, and steam distribution lines.
SS 304 Buttweld Fittings Specifications
Property | Details |
|---|---|
Specification | ASTM A403 / ASME SA403 |
Grade / UNS | SS 304 / UNS S30400 / WNR 1.4301 |
Dimensions | ASME/ANSI B16.9, B16.28, MSS-SP-43 |
Size Range | ½″ NB to 48″ NB |
Seamless up to | 24″ NB |
Welded / Fabricated | 8″ to 48″ NB |
Wall Thickness | Sch 5S, 10S, 20, 40S, STD, 80S, XS, 160S, XXS |
Bending Radius | 1D, 2D, 3D, 5D, 6D, 8D, 10D or Custom |
Heat Treatment | Solution Annealed @ 1040°C min |
Certification | MTC EN 10204 3.1; ISO 9001:2015 |
Chemical Composition of SS 304 Buttweld Fittings
Grade |
C max |
Mn max |
Si max |
P max |
S max |
Cr |
Ni |
N max |
|---|---|---|---|---|---|---|---|---|
SS 304 (UNS S30400) |
0.08 |
2.00 |
0.75 |
0.045 |
0.030 |
18.0–20.0 |
8.0–10.5 |
0.10 |
For the low-carbon variant with enhanced weld-zone corrosion resistance, see our SS 304L Buttweld Fittings page.
Mechanical Properties of Stainless Steel 304 Buttweld Fittings
Grade |
Tensile Strength (MPa min) |
Yield Strength (MPa min) |
Elongation (% min) |
Hardness HRB max |
Hardness HBW max |
|---|---|---|---|---|---|
SS 304 |
515 (75,000 psi) |
205 (30,000 psi) |
40% |
92 |
201 |
Equivalent Material Grades of ASTM A403 SS Buttweld Fittings
Grade |
UNS No. |
BS (Old) |
Euronorm No. |
Euronorm Name |
Swedish SS |
JIS |
|---|---|---|---|---|---|---|
SS 304 |
S30400 |
304S31 |
1.4301 |
X5CrNi18-10 |
2332 |
SUS 304 |
ASME B16.9 Dimensional Tolerances (mm)
DN / NPS |
OD Bevel End |
Wall Thickness |
Elbow (M/H) |
Tee (E/O) |
Reducer (K) |
180° Elbow |
|---|---|---|---|---|---|---|
15–65 / ½″–2½″ |
+1.6/−0.8 |
−12.5% |
±1.6 |
±1.6 |
±1.6 |
±6.4 |
80–100 / 3″–4″ |
±1.6 |
−12.5% |
±1.6 |
±1.6 |
±1.6 |
±6.4 |
125–200 / 5″–8″ |
+2.4/−1.6 |
−12.5% |
±2.4 |
±2.4 |
±2.4 |
±9.6 |
250–450 / 10″–18″ |
+4.0/−3.2 |
−12.5% |
±2.4 |
±2.4 |
±2.4 |
±9.6 |
500–600 / 20″–24″ |
+6.4/−4.8 |
−12.5% |
±3.2 |
±3.2 |
±4.8 |
±9.6 |
ASME B16.9 Angularity Tolerances for SS 304 Buttweld Fittings
NPS Range |
Off-Angle Q (°) |
Off-Plain P (mm) |
|---|---|---|
½″ – 4″ | 1° | 2 |
5″ – 8″ | 2° | 4 |
10″ – 12″ | 3° | 5 |
14″ – 16″ | 3° | 6 |
18″ – 24″ | 4° | 10 |
26″ – 30″ | 5° | 10 |
32″ – 42″ | 5° | 13 |
44″ – 48″ | 5° | 19 |
Heat Treatment Requirements for SS 304 Buttweld Fittings
All ASTM A403 WP304 Buttweld Fittings from Amardeep Steel are supplied in solution-annealed condition. The process involves heating to a minimum of 1040°C (1900°F) followed by rapid quenching in water or air. This dissolves chromium carbides that form during fabrication, fully restoring the material’s corrosion resistance and ductility, critical for welded joints entering service in chemical processing, pharmaceutical and high-purity environments.
Types of Stainless Steel 304 Buttweld Fittings
Amardeep Steel maintains an exhaustive inventory of SS 304 Buttweld Fittings to cover every piping configuration.
SS 304 Elbows
45°, 90° & 180° elbows in Long Radius (LR) and Short Radius (SR). Changes flow direction with minimal pressure loss. Available as seamless (up to 24″ NB) and welded types. Widely specified as ASTM A403 WP304 90 Degree Elbow and 45 Degree Elbow in process piping.
SS 304 Tees
Equal Tee and Reducing Tee in both seamless and welded execution. Creates a 90° branch connection from the main pipe run.
SS 304 Reducers
Concentric Reducers and Eccentric Reducers for connecting pipes of different diameters. Eccentric type prevents air/sediment trapping.
SS 304 Caps
End caps seal and terminate pipe ends. Available in Sch 5S to Sch 160 for complete pressure containment.
SS 304 Long Radius Bends
3D, 5D, and 10D bends offer gradual direction changes, minimising turbulence and pressure drop in high-flow systems.
SS 304 Cross Fittings
Equal and Reducing Crosses for four-way piping intersections in complex industrial piping layouts.
SS 304 Stub Ends
Long and Short Stub Ends (Lap Joint) for use with lap joint flanges, enabling easy disassembly and bolt-hole alignment.
SS 304 Swage Nipples
Barrel and Swage Nipples for connecting pipes or fittings of different sizes or end types in confined spaces.
SS 304 Buttweld Fittings – Dimension Chart
Key center-to-end and lap diameter dimensions per ASME B16.9 for common nominal pipe sizes.
NPS (in) |
OD (mm) |
OD (in) |
90° LR Elbow C-E (in) |
45° LR Elbow C-E (in) |
Cap Length (in) |
Tee C-E (in) |
Stub End Lap Ø (in) |
Stub End Long L (in) |
|---|---|---|---|---|---|---|---|---|
½″ | 21.3 | 0.840 | 1.50 | 0.62 | 1 | 1 | 1 3/8 | 3 |
¾″ | 26.7 | 1.050 | 1.50 | 0.62 | 1 | 1 1/8 | 1 11/16 | 3 |
1″ | 33.4 | 1.315 | 1.50 | 0.62 | 1 ½ | 1 ½ | 2 | 4 |
1½″ | 48.3 | 1.900 | 2.25 | 0.88 | 1 ½ | 2 ¼ | 2 7/8 | 4 |
2″ | 60.3 | 2.375 | 3.00 | 1.12 | 1 ½ | 2 ½ | 3 5/8 | 6 |
3″ | 88.9 | 3.500 | 4.50 | 1.69 | 2 | 3 3/8 | 5 | 6 |
4″ | 114.3 | 4.500 | 6.00 | 2.25 | 2 ½ | 4 1/8 | 6 3/16 | 6 |
6″ | 168.3 | 6.625 | 9.00 | 3.38 | 3 ½ | 5 5/8 | 8 ½ | 8 |
8″ | 219.1 | 8.625 | 12.00 | 4.50 | 4 | 7 | 10 5/8 | 8 |
10″ | 273.1 | 10.750 | 15.00 | 5.62 | 5 | 8 ½ | 12 ¾ | 10 |
12″ | 323.9 | 12.750 | 18.00 | 6.75 | 6 | 10 | 15 | 10 |
SS 304 Buttweld Fittings – Weight Chart (kg)
Theoretical weights for standard elbows and equal tees across Schedule 10S, 40S, and 80S.
DN |
Sch 10S – 90° Elbow |
Sch 10S – 45° Elbow |
Sch 10S – Equal Tee |
Sch 40S – 90° Elbow |
Sch 40S – Equal Tee |
Sch 80S – 90° Elbow |
Sch 80S – Equal Tee |
|---|---|---|---|---|---|---|---|
15 | 0.06 | 0.03 | 0.09 | 0.08 | 0.10 | 0.10 | 0.14 |
25 | 0.14 | 0.08 | 0.28 | 0.15 | 0.29 | 0.22 | 0.38 |
50 | 0.50 | 0.25 | 0.85 | 0.70 | 1.28 | 0.91 | 1.59 |
80 | 1.25 | 0.63 | 1.77 | 2.20 | 3.31 | 2.97 | 4.45 |
100 | 2.10 | 1.08 | 3.46 | 4.47 | 5.27 | 6.18 | 7.71 |
150 | 5.45 | 2.72 | 8.07 | 10.89 | 10.99 | 16.32 | 13.61 |
200 | 10.20 | 5.33 | 15.65 | 21.54 | 20.91 | 33.11 | 28.12 |
300 | 25.80 | 13.62 | 39.46 | 59.42 | 62.14 | 79.38 | 83.91 |
SS 304 Concentric & Eccentric Reducer Weight Chart (kg)
DN (mm) |
Sch 10S Con Reducer |
Sch 10S Ecc Reducer |
Sch 40S Con Reducer |
Sch 40S Ecc Reducer |
|---|---|---|---|---|
40×25 | 0.19 | 0.19 | 0.26 | 0.26 |
50×25 | 0.28 | 0.28 | 0.40 | 0.40 |
50×40 | 0.31 | 0.31 | 0.45 | 0.45 |
80×50 | 0.55 | 0.55 | 1.00 | 1.00 |
100×50 | 0.78 | 0.78 | 1.50 | 1.50 |
100×80 | 0.87 | 0.87 | 1.74 | 1.74 |
150×80 | 1.82 | 1.82 | 3.95 | 3.95 |
150×100 | 1.96 | 1.96 | 4.07 | 4.07 |
200×100 | 3.01 | 3.01 | 6.55 | 6.55 |
200×150 | 3.19 | 3.19 | 6.74 | 6.74 |
SS 304 Buttweld Fittings – Capacity & Availability
Seamless and welded SS 304 Buttweld Fittings available across all standard fitting types.
Product |
Seamless — Size Range |
Seamless — Schedule |
Welded — Size Range |
Welded — Schedule |
|---|---|---|---|---|
Elbow (90°, 45°, 180°) | ½″ – 24″ | Sch 10S – XXS | 8″ – 48″ | Sch 5S – 80S/XS |
Equal & Reducing Tee | ½″ – 24″ | Sch 10S – XXS | 8″ – 48″ | Sch 5S – 80S/XS |
Concentric & Eccentric Reducer | ½″ – 24″ | Sch 10S – XXS | 8″ – 48″ | Sch 5S – 80S/XS |
Cap | ½″ – 80″ | Sch 10S – Sch 160 | — | — |
Lap Joint Stub End | ½″ – 24″ | Sch 5S – 80S/XS | 8″ – 80″ | Sch 5S – 80S/XS |
Long Radius Bend (3D/5D/10D) | ½″ – 24″ | Sch 10S – 80S | 8″ – 48″ | Sch 5S – 80S |
Cross (Equal & Reducing) | ½″ – 12″ | Sch 10S – XXS | 6″ – 24″ | Sch 5S – 80S |
Industries Served by Stainless Steel 304 Buttweld Fittings
The versatility of UNS S30400 makes SS 304 Buttweld Fittings a top choice across critical industries worldwide.
- Oil & Gas
-
Petrochemical & Chemical
-
Power Generation
-
Food & Beverage
-
Pharmaceutical & Biotech
-
Water & Wastewater
-
Pulp & Paper
-
Textile
-
Nuclear Power
-
Desalination
-
Shipbuilding & Marine
-
Architecture & Construction
Why Choose Amardeep Steel for SS 304 Buttweld Fittings?
With over 25 years of manufacturing experience, Amardeep Steel operates state-of-the-art forging and forming facilities with in-line dimensional checks, PMI testing, and 100% visual inspection on every batch.
- Certified Quality — All SS 304 Buttweld Fittings are supplied with Mill Test Certificate (MTC) per EN 10204 3.1. Third-party inspection by TUV, DNV, and Lloyd’s available on request.
- Global Exports — Trusted by clients in the USA, Canada, UAE, Saudi Arabia, Germany, Singapore, and 50+ countries worldwide. Expert logistics for safe, on-time delivery with full documentation.
- Largest Inventory — Largest inventory of standard Stainless Steel 304 Buttweld Fittings in Mumbai for immediate despatch, minimising your project downtime and procurement lead times.
- Direct Manufacturer Pricing — No middlemen. Transparent, itemised quotes with fast turnaround on all standard and custom sizes.
- 24/7 Technical Support — Expert metallurgists and engineers for material selection, code compliance, and application-specific guidance.
Quality Testing & Packaging of SS 304 Buttweld Fittings
All SS 304 Buttweld Fittings manufactured by Amardeep Steel undergo the following before despatch: hydrostatic pressure testing, dimensional inspection per ASME B16.9, Positive Material Identification (PMI), and 100% visual inspection for surface defects. International shipments are secured in wooden crates with plastic end caps, oil-coated internal surfaces, and stencilled heat/lot marking per customer requirements.
Related Products
- SS 304L Buttweld Fittings
- SS 316 Buttweld Fittings
- Stainless Steel 304 Forged Fittings
- Stainless Steel 304L Forged Fittings
- Stainless Steel 304H Forged Fittings
- Stainless Steel 304/304L Pipe Fittings
- Stainless Steel Buttweld Fittings
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Frequently Asked Questions – SS 304 Buttweld Fittings
What does ASTM A403 WP304 mean?
ASTM A403 is the standard specification for wrought austenitic stainless steel piping fittings. “WP” stands for Wrought Pressure fitting, and “304” identifies the UNS S30400 grade — an 18% chromium, 8% nickel austenitic alloy. Our fittings are dual-certified under ASTM A403 and ASME SA403.
What is the available size range for SS 304 Buttweld Fittings?
Amardeep Steel supplies Stainless Steel 304 Buttweld Fittings in sizes ½″ NB to 48″ NB. Seamless fittings are available up to 24″ NB; welded and fabricated types cover 8″ to 48″ NB. Wall thicknesses range from Sch 5S through XXS.
What is the difference between SS 304 and SS 316 Buttweld Fittings?
SS 316 contains 2–3% molybdenum, which significantly improves resistance to chlorides, seawater, and aggressive industrial solvents. SS 304 Buttweld Fittings are more cost-effective and suitable for the vast majority of food, chemical, and industrial applications that don’t involve high chloride concentrations.
Are Stainless Steel 304 Buttweld Fittings suitable for food and pharmaceutical use?
Yes. The non-porous, hygienic surface of SS 304 prevents bacterial growth and product contamination. It is widely used in dairies, breweries, food processing plants, pharmaceutical manufacturing, and biotech clean rooms. Finish options include 2B, No. 4, and electropolish on request.
What certifications are supplied with Amardeep Steel’s SS 304 Buttweld Fittings?
Every shipment includes a Mill Test Certificate (MTC) per EN 10204 3.1 with full chemical and mechanical data. Third-party inspections by TUV, DNV GL, and Lloyd’s Register are available on request. Amardeep Steel is ISO 9001:2015 certified.
Can custom-radius bends be manufactured?
Absolutely. In addition to standard 1D, 3D, 5D, and 10D bends, Amardeep Steel fabricates custom-radius bends to your exact project drawings to optimise flow characteristics and spatial fit.
What heat treatment do SS 304 Buttweld Fittings require?
All ASTM A403 WP304 fittings are supplied in a solution-annealed condition — heated to a minimum of 1040°C (1900°F) and rapidly quenched. This dissolves chromium carbides formed during fabrication, fully restoring corrosion resistance, ductility, and toughness.
What is the difference between Long Radius (LR) and Short Radius (SR) SS 304 Buttweld Elbows?
A Long Radius (LR) elbow has a centre-to-end dimension of 1.5 times the nominal pipe diameter (1.5D), producing a gradual bend that minimises pressure drop and flow turbulence. A Short Radius (SR) elbow has a centre-to-end dimension equal to the nominal pipe diameter (1D), making it compact and suited for tight installations where a steeper bend is acceptable. LR elbows are standard for most process piping per ASME B31.3; SR elbows are used in structural or low-velocity service applications.
