Tubewell Steel & Engg. Co. is a leading manufacturer and stockist specializing in Alloy Steel Pipes, Tubes, Fittings and Flanges for critical industrial applications.
ASME B16.11 alloy steel socket weld and screwed fittings in ASTM A182 F11, F22 and F91 – elbows, tees, couplings, unions, plugs, bushings and olets.
Tubewell Steel & Engg. Co. is a manufacturer, stockist and supplier of alloy steel socket weld and threaded fittings in Mumbai, India. Forged from ASTM A182 chrome-moly material and machined to ASME B16.11, our fittings give strong, leak-tight joints on small-bore high-pressure lines without the need for butt-weld preparation.
Two proven joining methods for small-bore alloy piping
Socket weld fittings have a recessed socket into which the plain-end pipe is inserted and joined with a single fillet weld. A gap of about 1.6 mm (1/16") is left at the bottom of the socket to allow for thermal expansion of the weld. They offer excellent structural strength, easy alignment and no risk of weld metal entering the bore, which is why they are preferred for high-pressure drain, vent and instrument lines up to 2" – 4" NB.
Threaded (screwed) fittings use tapered NPT or BSPT threads and can be assembled without welding – ideal where hot work is restricted or lines need to be dismantled for maintenance. Tubewell supplies both types in ASTM A182 F5, F9, F11, F22 and F91, including 90° and 45° elbows, tees, crosses, full and half couplings, caps, unions, bosses, plugs, bushings, swage nipples (MSS SP-95) and branch olets (MSS SP-97). Every fitting is marked per MSS SP-25 and supplied with EN 10204 3.1 certificates.
Standard supply range for socket weld & threaded fittings
| Parameter | Details |
|---|---|
| Dimension Standard | ASME B16.11, MSS SP-79, MSS SP-83, MSS SP-95, MSS SP-97, BS 3799 |
| Material Standard | ASTM A182 / ASME SA182 |
| Grades | F5, F9, F11 Cl.1/2/3, F12, F22 Cl.1/3, F91 |
| Size Range | 1/8" NB to 4" NB |
| Socket Weld Class | Class 3000 (SCH 80), 6000 (SCH 160), 9000 (XXS) |
| Threaded Class | Class 2000 (SCH 80), 3000 (SCH 160), 6000 (XXS) |
| Thread Type | NPT (ASME B1.20.1), BSPT (ISO 7-1 / BS 21), BSPP |
| Elbows & Tees | 90° Elbow, 45° Elbow, Street Elbow, Equal Tee, Reducing Tee, Cross |
| Couplings | Full Coupling, Half Coupling, Reducing Coupling, Reducer Insert (MSS SP-79) |
| Others | Cap, Union (MSS SP-83), Boss, Hex / Square / Round Head Plug, Hex Bushing, Swage Nipple, Barrel Nipple |
| Olets (MSS SP-97) | Weldolet, Sockolet, Threadolet, Elbolet, Latrolet, Nipolet |
| Heat Treatment | Annealed or Normalized & Tempered per ASTM A182 |
| Testing | Hardness, PMI, Dimensional, Thread Gauging, Tensile, DPT / MPI on request |
| Certificates | EN 10204 3.1 / 3.2, IBR Certificate, TPI Reports |
Material grades used for our socket weld & threaded fittings
| Grade | ASTM | UNS | EN | W.Nr. | Matching Pipe |
|---|---|---|---|---|---|
| F5 | A182 F5 | K41545 | X11CrMo5 | 1.7362 | A335 P5 |
| F9 | A182 F9 | K90941 | X11CrMo9-1 | 1.7386 | A335 P9 |
| F11 | A182 F11 | K11597 / K11572 | 13CrMo4-5 | 1.7335 | A335 P11 |
| F22 | A182 F22 | K21590 | 10CrMo9-10 / 11CrMo9-10 | 1.7380 / 1.7383 | A335 P22 |
| F91 | A182 F91 | K90901 | X10CrMoVNb9-1 | 1.4903 | A335 P91 |
Weight %, as per ASTM A182 (range across grades shown in chips)
| Grade | C | Mn | P | S | Si | Cr | Mo | Others |
|---|---|---|---|---|---|---|---|---|
| F5 | 0.15 max | 0.30 – 0.60 | 0.030 max | 0.030 max | 0.50 max | 4.0 – 6.0 | 0.44 – 0.65 | Ni 0.50 max |
| F9 | 0.15 max | 0.30 – 0.60 | 0.030 max | 0.030 max | 0.50 – 1.00 | 8.0 – 10.0 | 0.90 – 1.10 | – |
| F11 Cl.2 | 0.10 – 0.20 | 0.30 – 0.80 | 0.040 max | 0.040 max | 0.50 – 1.00 | 1.00 – 1.50 | 0.44 – 0.65 | – |
| F22 Cl.3 | 0.05 – 0.15 | 0.30 – 0.60 | 0.040 max | 0.040 max | 0.50 max | 2.00 – 2.50 | 0.87 – 1.13 | – |
| F91 | 0.08 – 0.12 | 0.30 – 0.60 | 0.020 max | 0.010 max | 0.20 – 0.50 | 8.0 – 9.5 | 0.85 – 1.05 | V 0.18–0.25, Nb 0.06–0.10, N 0.03–0.07 |
Minimum values at room temperature as per ASTM A182
| Grade | Tensile Strength | Yield Strength (0.2%) | Elongation | Reduction of Area | Hardness (HBW) |
|---|---|---|---|---|---|
| F5 | 485 MPa (70 ksi) min | 275 MPa (40 ksi) min | 20% min | 35% min | 143 – 217 |
| F9 | 585 MPa (85 ksi) min | 380 MPa (55 ksi) min | 20% min | 40% min | 179 – 217 |
| F11 Cl.2 | 485 MPa (70 ksi) min | 275 MPa (40 ksi) min | 20% min | 30% min | 143 – 207 |
| F22 Cl.3 | 515 MPa (75 ksi) min | 310 MPa (45 ksi) min | 20% min | 30% min | 156 – 207 |
| F91 | 585 MPa (85 ksi) min | 415 MPa (60 ksi) min | 20% min | 40% min | 190 – 248 |
Typical values for chrome-moly fittings (for reference)
| Property | Metric | Imperial |
|---|---|---|
| Density | 7.75 – 7.85 g/cm³ | 0.280 – 0.284 lb/in³ |
| Melting Range | 1420 – 1510 °C | 2590 – 2750 °F |
| Modulus of Elasticity | 205 – 218 GPa | 29.7 – 31.6 × 10³ ksi |
| Thermal Conductivity (100°C) | 26 – 37 W/m·K | 15.0 – 21.4 BTU/h·ft·°F |
| Mean Thermal Expansion (20–300°C) | 11.3 – 12.6 µm/m·°C | 6.3 – 7.0 µin/in·°F |
| Specific Heat | 0.46 J/g·°C | 0.11 BTU/lb·°F |
| Typical Max. Service Temperature | F11 ≈ 595 °C, F22 ≈ 600 °C, F91 ≈ 650 °C | F11 ≈ 1100 °F, F22 ≈ 1110 °F, F91 ≈ 1200 °F |
Socket weld fittings as per ASME B16.11 – Class 3000 & 6000 (mm)
| NPS | Socket Bore (B) | Socket Depth (J) min | 90° Elbow / Tee / Cross (A) – 3000 | 90° Elbow / Tee / Cross (A) – 6000 | 45° Elbow (A) – 3000 | 45° Elbow (A) – 6000 |
|---|---|---|---|---|---|---|
| 1/8" | 10.9 | 9.5 | 11.0 | 11.0 | 8.0 | 8.0 |
| 1/4" | 14.3 | 9.5 | 11.0 | 13.5 | 8.0 | 8.0 |
| 3/8" | 17.7 | 9.5 | 13.5 | 15.5 | 8.0 | 11.0 |
| 1/2" | 21.9 | 9.5 | 15.5 | 19.5 | 11.0 | 13.0 |
| 3/4" | 27.3 | 12.5 | 19.5 | 22.5 | 13.0 | 14.0 |
| 1" | 34.0 | 12.5 | 22.5 | 27.0 | 14.0 | 17.0 |
| 1 1/4" | 42.8 | 12.5 | 27.0 | 32.0 | 17.0 | 21.0 |
| 1 1/2" | 48.9 | 12.5 | 32.0 | 38.0 | 21.0 | 25.0 |
| 2" | 61.2 | 16.0 | 38.0 | 41.0 | 25.0 | 28.0 |
| 2 1/2" | 73.9 | 16.0 | 41.0 | – | 28.0 | – |
| 3" | 89.9 | 16.0 | 57.0 | – | 32.0 | – |
| 4" | 115.5 | 19.0 | 66.5 | – | 41.0 | – |
A = Centre to bottom of socket. Class 3000 is used with SCH 80 pipe and Class 6000 with SCH 160 pipe. All dimensions in mm and nominal.
| NPS | Threaded Elbow / Tee / Cross (A) – Class 2000 | Threaded Elbow / Tee / Cross (A) – Class 3000 | Threaded Elbow / Tee / Cross (A) – Class 6000 | Threaded Coupling Length (W) |
|---|---|---|---|---|
| 1/8" | 21 | 21 | 25 | 32 |
| 1/4" | 21 | 25 | 28 | 35 |
| 3/8" | 25 | 28 | 33 | 38 |
| 1/2" | 28 | 33 | 38 | 48 |
| 3/4" | 33 | 38 | 44 | 51 |
| 1" | 38 | 44 | 51 | 60 |
| 1 1/4" | 44 | 51 | 60 | 67 |
| 1 1/2" | 51 | 60 | 64 | 79 |
| 2" | 60 | 64 | 83 | 86 |
| 2 1/2" | 76 | 83 | 95 | 92 |
| 3" | 86 | 95 | 106 | 108 |
| 4" | 106 | 114 | 114 | 121 |
Threaded fittings: A = Centre to end; W = overall length of full coupling (Class 3000 / 6000). Class 2000 suits SCH 80, Class 3000 suits SCH 160 and Class 6000 suits XXS pipe.
Where alloy steel socket weld & threaded fittings are used
Drain, vent and bypass lines on high-energy steam piping.
Gauge, transmitter and impulse line connections.
Small-bore hydrocarbon and hydrogen process piping.
Sampling, blow-down and safety valve branch connections.
Trap stations, condensate drains and warm-up lines.
High-temperature utility and process tapping points.
Quality you can verify on every heat
Large inventory for fast dispatch
MTC EN 10204 3.1 / 3.2
Positive material identification
Pan-India & export shipping
Quick answers about socket weld & threaded fittings
Get competitive pricing, ready stock and complete documentation.
