Stainless Steel 304 Pipe Fittings Supplier, Stainless Steel 304L Fittings Manufacturer & Exporter in India
Stainless Steel 304 pipe fittings are the most widely used austenitic stainless steel fittings in the world. Composed of approximately 18% chromium and 8% nickel often called "18/8" stainless — they deliver an outstanding balance of corrosion resistance, mechanical strength, weldability, and cost efficiency.
SS 304L pipe fittings are the low-carbon variant (max 0.03% C) specifically engineered for welded assemblies in corrosive environments. By limiting carbon content, 304L eliminates intergranular carbide precipitation during welding, making it the preferred grade wherever post-weld heat treatment is impractical.
At Amardeep Steel Centre, we carry both. Whether your inquiry is for ½″ instrument fittings or 48″ fabricated reducers, standard schedule or heavy wall, we supply the full range in compliance with ASTM A403 / ASME SA403 with dual-certified MTC so you're covered for either grade on the same heat.
Key Properties:
- Temperature resistance up to 870 °C intermittent / 925 °C continuous
- Minimum yield strength 215 MPa | Tensile strength 505 MPa
- Good resistance to oxidation, dilute acids, and moderate chemical exposure
- UNS S30400 (304) / UNS S30403 (304L) | Werkstoff No. 1.4301 / 1.4307
- Non-magnetic when annealed; may pick up slight magnetism after cold working
Table of Contents
- Types of SS 304 / 304L Pipe Fittings
- SS 304 vs SS 304L — Which Grade Do You Need?
- Stainless Steel 304 | Standard Grade
- Stainless Steel 304L | Low-Carbon Grade
- Stainless Steel 304 Pipe Fittings Specification
- Chemical Composition of SS 304 Fittings
- Mechanical Properties of SS 304L Fittings
- Dimensional Ranges of Butt-Weld Fittings
- Elbow Dimension Table per ASME B16.9
- Dimensions & Weight Chart NPS ½ to 48
- Threaded Pipe Fittings Dimensions
- Concentric & Eccentric Reducer Dimensions
- End Cap, Tee, Cross & Stub End Dimensions
- Elbow Dimensional Tolerance Chart
- Socket Weld Pipe Fittings Sizing
- 90 Elbow Angularity Tolerance
- Applicable Standards for SS 304 / 304L Fittings
- Fabrication Guide — Welding, Forming & Heat Treatment
- Industries We Serve
- Testing & Inspection
- Why Amardeep Steel for SS 304 / 304L Pipe Fittings?
- Related Products
- Frequently Asked Questions
Types of SS 304 / 304L Pipe Fittings
We supply the complete range of wrought and forged stainless steel 304/304L fittings — butt-weld, socket-weld, and threaded configurations.
SS 304 / 304L Elbow
Changes the direction of fluid flow. Available as 45° and 90° Long Radius (LR) or Short Radius (SR), and 180° return bends.
Std: ASME B16.9 / B16.28
SS 304 / 304L Tee
Connects three pipe sections. Supplied as Equal Tee (straight) and Reducing Tee to connect different pipe diameters.
Std: ASME B16.9
SS 304 / 304L Reducer
Reduces pipe diameter. Concentric Reducer maintains the centre line; Eccentric Reducer offsets it — ideal for pump inlets.
Std: ASME B16.9
SS 304 / 304L End Cap
Seals the open end of a pipeline. Hemispherical or flat face; suitable for pressure and vacuum services.
Std: ASME B16.9
SS 304 / 304L Stub End
Used with lap joint flanges to allow pipe rotation for easy bolt alignment. Available in short and long patterns.
Std: ASME B16.9 / MSS SP-43
SS 304 / 304L Cross
Connects four pipe sections at 90° angles. Used in distribution headers and complex piping networks.
Std: ASME B16.9
SS 304 / 304L Coupling
Full and half couplings for connecting smaller branch connections to a run pipe. Socket-weld and threaded types.
Std: ASME B16.11
SS 304 / 304L Union
A three-piece forged fitting enabling pipeline disassembly without cutting. Ideal for maintenance-intensive systems.
Std: MSS SP-83 / ASME B16.11
SS 304 / 304L Pipe Bend
Available in 1D, 2D, 3D, 5D, 6D, 8D, and 10D bending radius configurations. Used in space-constrained routing and low-friction long-radius flow lines. Manufactured per ASME B16.49 and custom fabrication.
Std: ASME B16.49 / MSS SP-75
SS 304 vs SS 304L — Which Grade Do You Need?
Both grades are dual-certified and interchangeable in most piping applications. The key difference lies in carbon content and welding performance.
Property | Stainless Steel 304 | Stainless Steel 304L |
|---|---|---|
UNS | S30400 | S30403 |
Werkstoff No. | 1.4301 | 1.4307 |
Carbon max | 0.08% | 0.03% |
Weldability | Excellent; post-weld annealing recommended for heavy sections | No post-weld heat treatment required in most applications |
Sensitisation risk | Present in heavy-gauge welded sections | Eliminated by low carbon content |
Tensile strength (min) | 515 MPa (75 ksi) | 485 MPa (70 ksi) |
Yield strength (min) | 205 MPa (30 ksi) | 170 MPa (25 ksi) |
Typical use | Non-welded or low-heat-input; food equipment, tanks, architecture | Heavy-gauge welded assemblies; chemical, pharma, marine |
Dual certification | Yes — where properties overlap | Yes — same stock, both MTCs |
Stainless Steel 304 | Standard Grade | UNS S30400
- Carbon max 0.08% — higher mechanical strength at elevated temperatures
- 18% Cr + 8% Ni "18/8" austenitic composition
- Excellent weldability; post-weld annealing recommended for heavy sections
- Ideal for non-welded or low-heat-input applications
- Slightly lower cost than 304L in some markets
- Common in food equipment, tanks, heat exchangers, architecture
Stainless Steel 304L | Low-Carbon Grade | UNS S30403
- Carbon max 0.03% — eliminates intergranular sensitisation during welding
- No post-weld heat treatment required in most applications
- Preferred for heavy-gauge welded assemblies and corrosive service
- Slightly lower tensile strength; compensated by reduced carbon
- Widely used in chemical processing, pharmaceuticals, marine environments
- Dual-certified with 304 when properties overlap — versatile and stocked
In most markets, dual-certified SS 304/304L stock carries no price premium over single-grade material — buyers receive MTC for both grades at the same unit cost. Contact us for a current price list.
Need SS 304 / 304L Pipe Fittings? Get a competitive quote with EN 10204 3.1 MTC in 24 hours.
Stainless Steel 304 Pipe Fittings Specification
Parameter | Details |
|---|---|
Specifications | ASTM A403 |
Thickness | SCH 80, SCH10, SCH20, SCH30, STD SCH40, SCH60, XS, SCH 120, SCH 140, SCH 100, SCH 160, XXS available with NACE MR 01-75 |
Dimensions | MSS-SP-43, ASME/ANSI B16.9, ASME B16.28, BS4504, BS1560, BS10 |
Test Certificates | EN 10204/3.1B | Raw Materials Certificate | 100% Radiography Test Report | Third Party Inspection Report |
Specialised manufacture of | Crosses, 90° Elbows, Tees, 45° Elbows, Reducers, Stub End, Pipe Cap, Pipe Bend |
Available Size Ranges | ½" NB to 24" NB in Sch 10s, 40s, 80s, 160s, XXS (DN6-DN600) |
Size | Seamless Fittings: 1/2" - 10" | Welded Fittings: 1/2" - 48" | DN15-DN1200 |
Bending Radius | R=3D, 1D, 2D, 6D, 8D, 5D, 10D |
Connection | Welding |
Manufacturing process | Cast, Forge, Push, Press, etc. |
Origin & Mills | Japanese, Indian, Korean, European, Ukraine, USA, Russian |
Chemical Composition of Stainless Steel 304 Fittings
ASTM A403 / ASME SA403 WP304 & WP304L — Wrought Austenitic Stainless Steel Pipe Fittings
Grade | C (max) | Mn (max) | Si (max) | P (max) | S (max) | Cr | Ni |
|---|---|---|---|---|---|---|---|
WP304 | 0.08 | 2.00 | 0.75 | 0.045 | 0.030 | 18.00-20.00 | 8.00-11.00 |
WP304L | 0.035 | 2.00 | 0.75 | 0.045 | 0.030 | 18.00-20.00 | 8.00-12.00 |
Mechanical Properties of Stainless Steel 304L Fittings
Grade | Tensile Strength (min) | Yield Strength (min) | Elongation (min) | Hardness (max) |
|---|---|---|---|---|
WP304 | 515 MPa (75 ksi) | 205 MPa (30 ksi) | 35% | 192 HBW |
WP304L | 485 MPa (70 ksi) | 170 MPa (25 ksi) | 35% | 192 HBW |
Dimensional Ranges of Butt-Weld Fittings
Fitting Type | Size Range (NB) | Wall Schedule | Dimensional Standard |
|---|---|---|---|
Elbow (45°/90°/180°) | ½" - 48" | 5S - XXS | ASME B16.9 / B16.28 |
Equal / Reducing Tee | ½" - 48" | 5S - XXS | ASME B16.9 |
Concentric / Eccentric Reducer | ¾"×½" - 48"×36" | 5S - XXS | ASME B16.9 |
End Cap | ½" - 48" | 5S - XXS | ASME B16.9 |
Stub End | ½" - 24" | 5S - 80S | ASME B16.9 / MSS SP-43 |
Cross | ½" - 24" | 5S - 80S | ASME B16.9 |
SW / Threaded Fittings | 1/8" - 4" | 2000# - 9000# | ASME B16.11 |
ASTM A403 WP304 / WP304L Fittings Dimension Table — 90°, 45°, 180° Elbows per ASME B16.9
NPS | OD (mm) | OD (in) | 90° LR C-F | 90° SR C-F | 45° LR C-F | 180° LR Radius | 180° C-C | 180° Back-F |
|---|---|---|---|---|---|---|---|---|
1/2 | 21.3 | 0.840 | 1½ | - | 5/8 | 2 | 1 7/8 | - |
3/4 | 26.7 | 1.050 | 1 1/8 | - | 7/16 | 2¼ | 1 11/16 | - |
1 | 33.4 | 1.315 | 1½ | 1 | 7/8 | 3 | 2 3/16 | - |
1¼ | 42.2 | 1.660 | 1 7/8 | 1¼ | 1 | 3¾ | 2¾ | - |
1½ | 48.3 | 1.900 | 2¼ | 1½ | 1 1/8 | 3 | 4½ | 3¼ |
2 | 60.3 | 2.375 | 3 | 2 | 1 3/8 | 4 | 6 | 4 3/16 |
2½ | 73.0 | 2.875 | 3¾ | 2½ | 1¾ | 5 | 7½ | 5 3/16 |
3 | 88.9 | 3.500 | 4½ | 3 | 2 | 6 | 9 | 6¼ |
4 | 114.3 | 4.500 | 6 | 4 | 2½ | 8 | 12 | 8¼ |
6 | 168.3 | 6.625 | 9 | 6 | 3¾ | 12 | 18 | 12 5/16 |
8 | 219.1 | 8.625 | 12 | 8 | 5 | 12 | 24 | 16 5/16 |
10 | 273.1 | 10.750 | 15 | 10 | 6¼ | 15 | 30 | 20 3/8 |
12 | 323.9 | 12.750 | 18 | 12 | 7½ | 18 | 36 | 24 3/8 |
Get ASTM A403 WP304 Elbow Dimensions Chart, 304 SS Reducing tee as per ANSI B16.9. We deliver high quality UNS S30400 Stainless steel buttweld pipe fittings.
SS 304 / 304L Pipe Fittings Dimensions & Weight Chart — NPS ½ to 48
NPS | 90° LR | 90° 3R | 90° SR | 45° 3R | 45° LR | 180° LR | 180° 3R | Tee C-E | StubEnd L | StubEnd M | Cap O | Cap K |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
½ | 1.50 | - | - | - | 0.62 | 1.88 | 3.00 | 1.00 | 3.00 | 2 | 0.12 | 1.38 |
¾ | 1.50 | - | - | - | 0.75 | 2.00 | 3.00 | 1.12 | 3.00 | 2 | 0.12 | 1.69 |
1 | 1.50 | - | 1.00 | - | 0.88 | 2.19 | 3.00 | 1.50 | 4.00 | 2 | 0.12 | 2.00 |
1¼ | 1.88 | - | 1.25 | - | 1.00 | 2.75 | 3.75 | 1.88 | 4.00 | 2 | 0.19 | 2.50 |
1½ | 2.25 | - | 1.50 | - | 1.12 | 3.25 | 4.50 | 2.25 | 4.00 | 2 | 0.25 | 2.88 |
2 | 3.00 | 6.00 | 2.00 | 2.50 | 1.38 | 4.19 | 6.00 | 2.50 | 6.00 | 2 | 0.31 | 3.62 |
2½ | 3.75 | 7.50 | 2.50 | 3.12 | 1.75 | 5.19 | 7.50 | 3.00 | 6.00 | 2 | 0.31 | 4.12 |
3 | 4.50 | 9.00 | 3.00 | 3.75 | 2.00 | 6.25 | 9.00 | 3.38 | 6.00 | 2 | 0.38 | 5.00 |
4 | 6.00 | 12.00 | 4.00 | 5.00 | 2.50 | 8.25 | 12.00 | 4.12 | 6.00 | 2 | 0.44 | 6.19 |
6 | 9.00 | 18.00 | 6.00 | 7.44 | 3.75 | 12.31 | 18.00 | 5.62 | 8.00 | 3.5 | 0.50 | 8.50 |
8 | 12.00 | 24.00 | 8.00 | 9.94 | 5.00 | 16.31 | 24.00 | 7.00 | 8.00 | 4 | 0.50 | 10.62 |
10 | 15.00 | 30.00 | 10.00 | 12.44 | 6.25 | 20.38 | 30.00 | 8.50 | 10.00 | 5 | 0.50 | 12.75 |
12 | 18.00 | 36.00 | 12.00 | 14.88 | 7.50 | 24.38 | 36.00 | 10.00 | 10.00 | 6 | 0.50 | 15.00 |
14 | 21.00 | 42.00 | 14.00 | 17.38 | 8.75 | 28.00 | 42.00 | 11.00 | 12.00 | 6.5 | 0.50 | 16.25 |
16 | 24.00 | 48.00 | 16.00 | 19.88 | 10.00 | 32.00 | 48.00 | 12.00 | 12.00 | 7 | 0.50 | 18.50 |
18 | 27.00 | 54.00 | 18.00 | 22.38 | 11.25 | 36.00 | 54.00 | 13.50 | 12.00 | 8 | 0.50 | 21.00 |
20 | 30.00 | 60.00 | 20.00 | 24.88 | 12.50 | 40.00 | 60.00 | 15.00 | 12.00 | 9 | 0.50 | 23.00 |
22 | 33.00 | 66.00 | 22.00 | 27.31 | 13.50 | 44.00 | 66.00 | 16.50 | 12.00 | 10 | 0.50 | 25.25 |
24 | 36.00 | 72.00 | 24.00 | 29.81 | 15.00 | 48.00 | 72.00 | 17.00 | 12.00 | 10.5 | 0.50 | 27.25 |
26 | 39.00 | 78.00 | - | 32.31 | 16.00 | - | - | 19.50 | - | 10.5 | - | - |
28 | 42.00 | 84.00 | - | 34.75 | 17.25 | - | - | 20.50 | - | 10.5 | - | - |
30 | 45.00 | 90.00 | - | 37.25 | 18.50 | - | - | 22.00 | - | 10.5 | - | - |
36 | 54.00 | 108.00 | - | 44.69 | 22.25 | - | - | 26.50 | - | 10.5 | - | - |
42 | 63.00 | 126.00 | - | 52.19 | 26.00 | - | - | 30.00 | - | 12 | - | - |
48 | 72.00 | 144.00 | - | 59.69 | 29.88 | - | - | 35.00 | - | 13.5 | - | - |
SS 304 / 304L Threaded Pipe Fittings Dimensions — DN-NPT Size Chart
DN-NPT | Major Diam. (mm) | Tapping Drill (mm) | TPI | Pitch (mm) |
|---|---|---|---|---|
1/16" | 7.895 | 6.00 | 27 | 0.941 |
1/8" | 10.242 | 8.25 | 27 | 0.941 |
1/4" | 13.616 | 10.70 | 18 | 1.411 |
3/8" | 17.055 | 14.10 | 18 | 1.411 |
1/2" | 21.223 | 17.40 | 14 | 1.814 |
3/4" | 26.568 | 22.60 | 14 | 1.814 |
1" | 33.228 | 28.50 | 11.5 | 2.209 |
1¼" | 41.985 | 37.00 | 11.5 | 2.209 |
1½" | 48.054 | 43.50 | 11.5 | 2.209 |
2" | 60.092 | 55.00 | 11.5 | 2.209 |
2½" | 72.699 | 65.50 | 8 | 3.175 |
3" | 88.608 | 81.50 | 8 | 3.175 |
3½" | 101.316 | 94.30 | 8 | 3.175 |
4" | 113.973 | 107.00 | 8 | 3.175 |
5" | 141.300 | 134.384 | 8 | 3.175 |
6" | 168.275 | 161.191 | 8 | 3.175 |
8" | 219.075 | 211.673 | 8 | 3.175 |
10" | 273.050 | 265.311 | 8 | 3.175 |
12" | 323.850 | 315.793 | 8 | 3.175 |
SS 304 / 304L Concentric & Eccentric Reducer Dimensions per ASME B16.9
NPS | OD (mm) | OD (in) | Reduced To | C&E Length (in) |
|---|---|---|---|---|
1/2 | 21.3 | 0.840 | 3/8 | 1½ |
3/4 | 26.7 | 1.050 | 3/8, 1/2 | 2 |
1 | 33.4 | 1.315 | 3/8, 1/2, 3/4 | 2 |
1¼ | 42.2 | 1.660 | 1/2, 3/4, 1 | 2 |
1½ | 48.3 | 1.900 | 1/2, 3/4, 1, 1¼ | 2½ |
2 | 60.3 | 2.375 | 3/4, 1, 1¼, 1½ | 3 |
2½ | 73.0 | 2.875 | 1, 1¼, 1½, 2 | 3½ |
3 | 88.9 | 3.500 | 1, 1½, 2, 2½ | 3½ |
3½ | 101.6 | 4.000 | 1¼, 1½, 2, 2½, 3 | 4 |
4 | 114.3 | 4.500 | 1½, 2, 2½, 3, 3½ | 4 |
5 | 141.3 | 5.563 | 2, 2½, 3, 3½, 4 | 5 |
6 | 168.3 | 6.625 | 2½, 3, 3½, 4, 5 | 5½ |
8 | 219.1 | 8.625 | 3, 3½, 4, 5, 6 | 6 |
10 | 273.1 | 10.750 | 4, 5, 6, 8 | 7 |
12 | 323.9 | 12.750 | 5, 6, 8, 10 | 8 |
SS 304 / 304L End Cap, Tee, Cross & Stub End Dimensions per ASME B16.9
NPS (in) | OD (mm) | OD (in) | Cap Length | Tee C-E | Cross C-E | Stub Lap Dia | Stub Long | Stub Short |
|---|---|---|---|---|---|---|---|---|
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 | 1½ | 1½ | 1½ | 2 | 4 | 2 |
1¼ | 42.2 | 1.660 | 1½ | 1 7/8 | 1 7/8 | 2½ | 4 | 2 |
1½ | 48.3 | 1.900 | 1½ | 2¼ | 2¼ | 2 7/8 | 4 | 2 |
2 | 60.3 | 2.375 | 1½ | 2½ | 2½ | 3 5/8 | 6 | 2½ |
2½ | 73.0 | 2.875 | 1½ | 3 | 3 | 4 1/8 | 6 | 2½ |
3 | 88.9 | 3.500 | 2 | 3 3/8 | 3 3/8 | 5 | 6 | 2½ |
3½ | 101.6 | 4.000 | 2½ | 3¾ | 3¾ | 5½ | 6 | 3 |
4 | 114.3 | 4.500 | 2½ | 4 1/8 | 4 1/8 | 6 3/16 | 6 | 3 |
5 | 141.3 | 5.563 | 3 | 4 7/8 | 4 7/8 | 7 5/16 | 8 | 3 |
6 | 168.3 | 6.625 | 3½ | 5 5/8 | 5 5/8 | 8½ | 8 | 3½ |
8 | 219.1 | 8.625 | 4 | 7 | 7 | 10 5/8 | 8 | 4 |
10 | 273.1 | 10.750 | 5 | 8½ | 8½ | 12¾ | 10 | 5 |
12 | 323.9 | 12.750 | 6 | 10 | 10 | 15 | 10 | 6 |
SS 304 / 304L Elbow Dimensional Tolerance Chart — DN 15 to 1500 per ASME B16.9
DN | NPS | OD Bevel End | ID End | Wall Thick | Elbow | Tee | Reducer | Cap | 180° Elbow |
|---|---|---|---|---|---|---|---|---|---|
15-65 | 1/2-2½ | +1.6/−0.8 | 0.8 | −12.50% | 1.6 | 1.6 | 1.6 | 1.6 | 1.6 |
80-100 | 3-4 | 1.6 | 1.6 | −12.50% | 1.6 | 1.6 | 1.6 | 1.6 | 1.6 |
125-200 | 5-8 | +2.4/−1.6 | 1.6 | −12.50% | 1.6 | 1.6 | 1.6 | 1.6 | 1.6 |
250-450 | 10-18 | +4/−3.2 | 3.2 | −12.50% | 2.4 | 2.4 | 2.4 | 2.4 | 2.4 |
500-600 | 20-24 | +6.4/−4.8 | 4.8 | −12.50% | 3.2 | 3.2 | 3.2 | 3.2 | 4.8 |
650-750 | 26-30 | 4.8 | — | — | 4.8 | 4.8 | 4.8 | 4.8 | — |
800-1200 | 32-48 | — | — | — | — | — | — | — | — |
1250-1500 | 50-60 | +9.6/−6.4 | 6.4 | — | 9.6 | 9.6 | 9.6 | 9.6 | 9.6 |
SS 304 / 304L Socket Weld Pipe Fittings Sizing — Class 3000, 6000, 9000 per ASME B16.11
Fitting Type | Class 3000 (SCH 80 & XS) | Class 6000 (SCH 160) | Class 9000 (XXS) |
|---|---|---|---|
90° & 45° Elbow | ½" - 4" | ½" - 2" | ½" - 2" |
Cross | ½" - 4" | ½" - 2" | ½" - 2" |
Pipe Tee | ½" - 4" | ½" - 2" | ½" - 2" |
Forged Coupling | ½" - 4" | ½" - 2" | ½" - 2" |
Half-Coupling | ½" - 4" | ½" - 2" | ½" - 2" |
End / Pipe Caps | ½" - 4" | ½" - 2" | ½" - 2" |
SS 304 / 304L 90° Elbow Angularity Tolerance — NPS ½ to 60
DN | NPS | Off Angle (Q) | Off Plain (P) |
|---|---|---|---|
15-100 | 1/2-4 | 1° | 2 mm |
125-200 | 5-8 | 2° | 4 mm |
250-300 | 10-12 | 3° | 5 mm |
350-400 | 14-16 | 3° | 6 mm |
450-600 | 18-24 | 4° | 10 mm |
650-750 | 26-30 | 5° | 10 mm |
800-1050 | 32-42 | 5° | 13 mm |
1100-1200 | 44-48 | 5° | 19 mm |
1300-1500 | 52-60 | 6.4 mm | 20 mm |
Applicable Standards for SS 304 / 304L Fittings
Our fittings are manufactured and tested per the following international codes and standards.
Standard | Scope |
|---|---|
ASTM A403 | Wrought Austenitic SS Pipe Fittings (WP304 / WP304L) |
ASME SA403 | ASME equivalent of ASTM A403 for pressure vessels |
ASTM A182 | Forged / Rolled Alloy Fittings (Grade F304 / F304L) |
ASME B16.9 | Factory-Made Wrought Butt-Weld Fittings |
ASME B16.11 | Forged Fittings — Socket-Weld & Threaded |
ASME B16.28 | Wrought Steel Butt-Weld Short Radius Elbows & Returns |
MSS SP-43 | Light Weight SS Butt-Weld Fittings |
MSS SP-79 | Socket-Weld Reducer Inserts |
MSS SP-97 | Integrally Reinforced Forged Branch Outlet Fittings |
EN 10253 | European butt-weld pipe fittings standard |
DIN 2605-2617 | German / European dimensional standards |
PED 2014/68/EU | Pressure Equipment Directive — EU market compliance |
Fabrication Guide - Welding, Forming & Heat Treatment of SS 304 / 304L Fittings
Annealing & Heat Treatment
Types 304 and 304L cannot be hardened by thermal treatment. Full anneal: heat to 1010-1120 °C (1850-2050 °F) and cool at sufficiently high rates through 815-425 °C (1500-800 °F) to avoid precipitation of chromium carbides. Stress relief anneal: cold-worked parts should be stress relieved at 400 °C (750 °F) for ½ to 2 hours.
Forming & Cold Working
Annealed 304 and 304L can be fabricated by roll forming, deep drawing, bending, and most other fabrication techniques. Due to the high work-hardening rate of austenitic stainless steels, intermediate anneals may be required to successfully complete multi-stage forming operations.
Welding SS 304 / 304L
Both grades are weldable by most fusion and resistance welding techniques. Where filler metal is required, AWS Type 308 / 308L is normally used. For 304 (standard carbon), post-weld annealing is recommended in heavy-gauge sections to minimise intergranular carbide precipitation in the heat-affected zone. For 304L, no post-weld heat treatment is required in most service conditions.
Industries We Serve
SS 304 / 304L pipe fittings are the go-to choice across industries that demand corrosion resistance, hygienic surfaces, and mechanical reliability.
Industry | Industry | Industry |
|---|---|---|
Oil & Gas | Chemical & Petrochemical | Pharmaceuticals |
Food, Beverage & Dairy | Water Treatment | Power Generation |
Marine & Offshore | Construction & Architecture | Heat Exchangers |
Pulp & Paper | Semiconductor & Electronics | Aerospace |
SS 304 / 304L pipe fittings are specified in food and beverage lines for their non-reactive 18/8 surface finish and compliance with FDA and EU food-contact regulations. In pharmaceutical and biotech plants, they meet GMP and USP Class VI requirements for clean-room piping. In chemical processing, their resistance to dilute acids, alkalis, and organic solvents at temperatures up to 300 °C makes them the standard choice for moderate-corrosion service pipework.
Testing & Inspection — SS 304 / 304L Pipe Fittings
Every batch of SS 304 / 304L fittings supplied by Amardeep Steel undergoes rigorous third-party and in-house testing to ensure full compliance with ASTM A403 and customer specifications.
Test | Description |
|---|---|
Chemical Analysis | Spectrometric (OES) and wet chemical analysis verifying Cr, Ni, C, Mn, Si, P, S content against ASTM A403 requirements. |
Mechanical Testing | Tensile test, yield strength, elongation, and Brinell/Rockwell hardness testing per ASTM A370. |
Hydrostatic / Hydro Test | Pressure-tested to confirm leak-free integrity before dispatch. Test pressures per ASME B31.3 / B31.1. |
Non-Destructive Testing (NDT) | Dye Penetrant (DP/PT), Radiography (RT), Ultrasonic Testing (UT), and Magnetic Particle (MPT) as required by customer spec. |
Dimensional Inspection | 100% dimensional verification per ASME B16.9, B16.11, or B16.28 using calibrated instruments with recorded data. |
Positive Material Identification (PMI) | XRF or OES PMI testing to confirm alloy grade - eliminating mix-ups and ensuring traceability from heat to finished fitting. |
All fittings are supplied with Mill Test Certificates (MTC) as per EN 10204 3.1 / 3.2. Third-party inspection by SGS, Bureau Veritas, Lloyds, TÃœV, or any other approved agency can be arranged on request.
Why Amardeep Steel for SS 304 / 304L Pipe Fittings?
With 30+ years of experience and a reputation built on quality and reliability, Amardeep Steel Centre is the preferred source for stainless steel pipe fittings across 80+ countries.
- Large Ready Stock: Extensive inventory of butt-weld, forged, and threaded fittings in all standard sizes — available for same-day dispatch from our Mumbai warehouse.
- Full Size Range: NPS 1/8" to 48" in Schedules 5S through XXS, plus custom sizes on request.
- Certified Quality: ISO 9001:2015 | PED 2014/68/EU | NORSOK M-650 | AD 2000 Merkblatt W0. All fittings supplied with EN 10204 3.1 MTC.
- Third-Party Inspection: SGS, Bureau Veritas, Lloyd's, TUV, DNV — arranged on request at no extra lead time.
- Global Exports: Regular shipments to the USA, Canada, UAE, Saudi Arabia, Germany, UK, Australia, Singapore, and 70+ other countries.
- Custom Fabrication: Non-standard radii, wall thicknesses, and end preparations — manufactured to your drawing.
- Technical Support: Our metallurgists and piping engineers assist with grade selection, corrosion assessments, and welding procedure guidance — 24/7.
Related Products
- Stainless Steel 316 / 316L Pipe Fittings
- Stainless Steel Butt-Weld Fittings
- Stainless Steel Forged Fittings
- Stainless Steel 347 Forged Fittings
- Stainless Steel 904L Forged Fittings
Get Your SS 304 / 304L Pipe Fittings Quote
Contact us for a competitive quote with EN 10204 3.1 MTC. Stock available ex-Mumbai for immediate dispatch worldwide.
Frequently Asked Questions — SS 304 / 304L Pipe Fittings
Everything you need to know before sourcing stainless steel 304 or 304L pipe fittings.
1. What is the difference between SS 304 and SS 304L pipe fittings?
SS 304 contains up to 0.08% carbon, giving it slightly higher mechanical strength at elevated temperatures. SS 304L is the low-carbon variant (max 0.03% C) engineered to eliminate intergranular carbide precipitation during welding. When piping systems require heavy welding without post-weld heat treatment — or when the service environment is particularly corrosive — SS 304L is the preferred choice. In many cases, fittings are dual-certified 304/304L, meeting both grade requirements simultaneously.
2. What standard covers SS 304 / 304L pipe fittings?
Wrought austenitic stainless steel pipe fittings are governed by ASTM A403 / ASME SA403 with grades WP304 and WP304L. Butt-weld dimensions are per ASME B16.9 (standard) and ASME B16.28 (short radius). Forged socket-weld and threaded fittings conform to ASME B16.11 and forged material to ASTM A182 grades F304/F304L.
3. What size range is available for SS 304 pipe fittings?
Butt-weld fittings are available from ½″ NB to 48″ NB. Seamless versions are typically available up to 10″ NB; larger sizes are welded or fabricated. Forged socket-weld and threaded fittings range from 1/8″ to 4″. Wall thickness schedules available include 5S, 10S, 40S, 80S, 120, 160, and XXS.
4. Which industries commonly use SS 304 / 304L pipe fittings?
SS 304 / 304L pipe fittings are used across food and beverage, pharmaceutical, dairy, chemical and petrochemical, oil and gas, water treatment, power generation, marine, cryogenic, paper and pulp, semiconductor, and architectural applications. Their 18% Cr + 8% Ni composition makes them resistant to a broad range of corrosive environments at moderate temperatures.
5. What tests are performed on SS 304/304L pipe fittings before supply?
Standard tests include: chemical composition analysis (spectrometric), mechanical testing (tensile, yield, hardness per ASTM A370), hydrostatic testing, dimensional inspection per ASME B16.9/B16.11, and visual inspection. Optional tests available on request include dye penetrant (DP/PT), radiography (RT), ultrasonic (UT), intergranular corrosion test (IGC per ASTM A262), and PMI. All supplied with MTC 3.1 (or 3.2 on request).
6. Can SS 304 and 304L pipe fittings be used interchangeably?
In many piping systems, yes — dual-certified 304/304L fittings satisfy both grade requirements simultaneously. The main consideration is service: for applications involving heavy welding or highly corrosive environments (acids, chlorides, etc.), 304L is recommended. For general service without significant welding, standard 304 is perfectly suitable and may offer marginally higher tensile strength at elevated temperatures.
7. What is the maximum temperature for SS 304 pipe fittings?
SS 304 / 304L fittings demonstrate good oxidation resistance in intermittent service up to 870°C (1600°F) and in continuous service up to 925°C (1700°F). However, continuous use between 425–860°C is not recommended for 304 (only 304L) in corrosive environments, due to carbide precipitation risk. For high-temperature applications above these ranges, grades 310S, 321, or 347 may be more appropriate.
8. What is the price of SS 304 / 304L pipe fittings?
Price depends on size, wall schedule, quantity, and source mill. For standard stock sizes, ex-works pricing is available with MOQ of 1 piece. Dual-certified 304/304L stock typically carries no price premium over single-grade material. Contact us for a current price list with MTC.
9. What is the delivery time for SS 304 / 304L pipe fittings from India?
Stock items ship within 2–5 business days from Mumbai ex-works. Non-stock sizes and custom schedules carry a 3–6 week manufacturing lead time depending on specifications and order quantity. Express dispatch is available for urgent requirements — contact our sales team with your timeline.
