Stainless Steel Grades

High-Quality Stainless Steel Pipe Fittings – Buttweld, Socket Weld, Threaded, Olets – ISO Approved - ANSI/ASME B16.5/B16.9/B16.11.

Stainless steel is a high-performance alloy used extensively in the manufacturing of buttweld fittings, flanges, forged fittings, and olets, owing to its superior corrosion resistance, durability, and versatility. Grades such as 304, 304L, 316, 316L, 310, 321, 347, 410, and 430, along with duplex variants like 2205 and 2507, are commonly available in a wide range of industrial fittings. These grades are produced in compliance with ASTM/ASME standards like B16.9, B16.5, B16.11, and MSS SP-97, ensuring precision and reliability for critical piping systems.

Austenitic stainless steels like 304/304L and 316/316L are preferred materials for buttweld elbows, tees, reducers, and stub ends due to their weldability and excellent resistance to general corrosion. In high-temperature and chemical processing environments, grades such as 310 and 321 are commonly used for flanges like WNRF, SORF, Blind, RTJ, and others, offering stability at elevated temperatures. These components are essential in food processing, petrochemical, and HVAC systems where both hygiene and durability are critical.

Martensitic and ferritic stainless steels such as 410, 420, and 430 are ideal for forged socket weld and threaded fittings, including elbows, tees, unions, couplings, and plugs. These grades provide high strength and moderate corrosion resistance, making them suitable for high-pressure systems. Duplex and super duplex steels are increasingly used for olets like weldolets, sockolets, and threadolets, where superior mechanical strength and resistance to chloride stress corrosion cracking are vital, especially in offshore and marine applications.

Manufactured as per ASME and DIN standards, stainless steel fittings and flanges are available in sizes from ½” to 48” and pressure classes from 150 to 2500#. Each product undergoes rigorous quality checks, including PMI, UT, and hydro testing. Whether it’s a custom-fabricated reducer or a precision-machined forged union, stainless steel grades offer flexibility for diverse industries such as oil & gas, desalination, pharmaceuticals, and power generation. With global export capability, stainless steel piping components are ready for dispatch in both standard and non-standard configurations.

Manufacturer & Stockist of Stainless Steel Grades 304, 304L, 316, 316L, 310, 321, 347, 317L, 904L, 400 Series – Buttweld Elbows, Tees, Reducers, Stub Ends – Flanges: WNRF, SORF, BLRF – Forged SW/Threaded Fittings – Outlet Fittings (Weldolet, Sockolet, Threadolet) as per MSS SP-97 – ANSI/ASME B16.5, B16.9, B16.11 – Pressure Class 150# to 2500#.

Industrial Stainless Steel Specifications

Material Grade Stainless Steel 304, 304L, 316, 316L, 310, 310S, 321, 321H, 347, 347H, 904L / 1.4301, 1.4306, 1.4307, 1.4401, 1.4404, 1.4841, 1.4845, 1.4541, 1.4878, 1.4550, 1.4961, 1.4539 / UNS S30400, S30403, S31600, S31603, S31000, S31008, S32100, S32109, S34700, S34709, N08904
Available Product Types Flanges, Buttweld Fittings, Forged Fittings, Olets
Flanges Size Range ½” (15 NB) to 48” (1200 NB)
Class 150, 300, 600, 900, 1500, 2500, PN6, PN10, PN16, PN25, PN40, PN64
Standard Specifications ASTM A182, A403 / ASME SA182, SA403
Standards ASME B16.5, B16.47 Series A & B, B16.48, EN 1092-1, DIN, BS4504, BS10, ISO 7005-1, GOST, JIS B2220, MSS SP-44, API 605
Types Weld Neck Flange (WNRF), Slip-On Flange (SORF), Socket Weld Flange (SWRF), Threaded Flange, Blind Flange (BLRF), Lap Joint Flange, Ring Type Joint Flange (RTJ), Long Weld Neck Flange, Reducing Flange, Expander Flange, Orifice Flange, Spectacle Blind Flange, Spacer Flange, Paddle Blank, Paddle Spacer, Raised Face (RF), Flat Face (FF), Large Male-Female (LMF), Small Male-Female (SMF), Tongue & Groove
Buttweld Fittings Size ½” NB to 24” NB (seamless), ½” NB to 48” NB (welded)
Wall Thickness SCH 10, SCH 20, SCH 40, SCH 80, SCH 160, XXS
Standards ASME B16.9, MSS SP-75, EN 10253, DIN 2605/2615/2616, ISO 3419, JIS B2312
Types Elbow (90°, 45°, Long Radius, Short Radius), Tee (Equal & Reducing), Reducer (Concentric & Eccentric), Caps, Stub Ends
Forged Fittings Size ½” NB to 4” NB (Socket Weld & Threaded)
Class Class 2000, 3000, 6000, 9000 (psi)
Standards ASME B16.11, MSS SP-83, MSS SP-95, JIS B2316
Types 90° Elbow, 45° Elbow, Tee, Cross, Full Coupling, Half Coupling, Pipe Cap, Union, Reducer Insert, Boss, Hex Head Bushing, Hex Head Plug, Square Head Plug, Round Head Plug, Bull Plug, Boss, Outlet, Hex Nipple, Swage Nipple
Olets (Outlet Fittings) Size Branch Sizes ½” to 24” | Run Pipe Sizes up to 36” (custom)
Class 3000#, 6000#, 9000#
Standards MSS SP-97, ASME B16.11, ANSI, DIN, EN, JIS (custom)
Types Weldolet, Sockolet, Threadolet, Elbolet, Latrolet, Nipolet, Sweepolet, Brazolet
End Connection Types Buttweld, Socket Weld, Threaded (NPT/BSP), Flanged (RF, FF, RTJ), Custom Branch Outlets
Testing & Certifications EN 10204 3.1 & 3.2, NACE MR0175, NACE MR0103, IBR, PMI, Ultrasonic Test, Radiography, Magnetic Particle Inspection
Surface Finish Options Pickled, Passivated, Mirror Finish, Satin Finish, Sandblasted, Coated (Black, Yellow Transparent, Zinc)
Manufacturing Capabilities CNC Machining, Cold/Hot Forming, Beveling, Drilling, Induction Heating, Forging, Custom Fabrication
Raw Material Sources India, Japan, South Korea, USA, Germany, Italy
Export Destinations USA, UAE, Saudi Arabia, Qatar, Kuwait, Oman, Egypt, South Africa, Kenya, Nigeria, Singapore, Malaysia, Australia

Industrial Stainless Steel Standards

ANSI/ASME B16.47 Flanges ANSI/ASME B16.36 Flanges ANSI/ASME B16.5 Flanges Pr. EN1902-1 Flanges
DIN Flanges JIS Flanges BS 4504 Flanges BS 10 Flanges
MSS SP-44 Flanges JIS B2220 Flanges KS B1503 Flanges UNI Flanges
SABS/SANS 1123 Flanges AS 2129, AS 4087 Flanges ISO 9624, ISO 7005-1 Flanges AWWA Flanges Standard
GOST Standard Flanges API Flanges AS/ANZ 4331.1 Flanges Series A Flange
Series B Flange SAE J518 Flanges GB Flange Norwegian Standard Flanges
ASME B16.11 – Forged Steel Fittings, Socket-Welding and Threaded BS 3799 – Screwed and Socket-Welding for the Petroleum Industry MSS SP-79 – Socket-Welding Reducer Inserts MSS SP-83 – Class 3000 Steel Pipe Unions, Socket-Welding and Threaded
MSS SP-95 – Swage(d) Nipples and Bull Plugs MSS SP-97 – Integrally Reinforced Forged Branch Outlet Fittings DIN 2986 – Threaded Fittings DIN 2999 – Pipe Threads for Fittings (British Standard Pipe Threads)
ISO 49 – Malleable Iron Fittings, Threaded ISO 7/1 – Pipe Threads Where Pressure-tight Joints Are Made on the Threads EN 10241 – Steel Threaded Pipe Fittings JIS B2316 – Japanese standard for forged pipe fittings.
ANSI/ASME B16.9 – Factory-Made Wrought Steel Buttwelding Fittings ANSI/ASME B16.28 – Wrought Steel Short Radius Elbows and Returns ANSI/ASME B16.25 – Buttwelding Ends(beval standards) MSS SP-43 – Wrought and fabricated Butt welding Fittings for Light Wall Applications
MSS SP-75 – High Test Wrought Butt welding Fittings DIN 2616 – Butt welding Pipe Fittings: Reducers DIN 2617 – Butt welding Pipe Fittings: Caps DIN28011 – Dished Ends(used in pressure vessels)
EN10253-1 Butt-welding Pipe Fittings(Non Alloy Steels) EN10253-2 Butt-welding Pipe Fittings(Stainless/Alloy Steels)

Stainless Steel International Standards

STANDARD WERKSTOFF NR. UNS JIS BS GOST AFNOR EN
SS 304 1.4301 S30400 SUS 304 304S31 08Х18Н10 Z7CN18‐09 X5CrNi18-10
SS 304L 1.4306 / 1.4307 S30403 SUS 304L 304S11 03Х18Н11 Z3CN18‐10 X2CrNi18-9 / X2CrNi19-11
SS 316 1.4401 S31600 SUS 316 316S31 08Х17Н13М2 Z7CND17‐11‐02 X5CrNiMo17-12-2
SS 316L 1.4404 / 1.4435 S31603 SUS 316L 316S11 03Х17Н14М2 Z2CND17‐12 X2CrNiMo17-12-2
SS 316Ti 1.4571 S31635 SUS 316Ti 320S31 10Х17Н13М2Т Z6CNDT17-12 X6CrNiMoTi17-12-2
SS 317 1.4449 S31700 SUS 317 317S16 X5CrNiMo18-18
SS 317L 1.4438 S31703 SUS 317L 317S11 Z2CND18-14 X2CrNiMo18-15-4
SS 321 1.4541 S32100 SUS 321 321S31 08Х18Н10Т Z6CNT18-10 X6CrNiTi18-10
SS 321H 1.4878 S32109 SUS 321H 321S51 12Х18Н10Т X8CrNiTi18-10
SS 347 1.4550 S34700 SUS 347 347S31 08Х18Н12Б Z6CNNb18-10 X6CrNiNb18-10
SS 347H 1.4961 S34709 SUS 347H 347S51 12Х18Н12Б X8CrNiNb18-10
SS 310 1.4841 S31000 SUS 310 310S24 20Х23Н18 Z15CN24-11 X15CrNi25-20
SS 310S 1.4845 S31008 SUS 310S 310S16 20Х23Н18 Z12CN25-20 X8CrNi25-21
SS 309 1.4828 S30900 SUS 309 309S24 20Х23Н13 Z15CN24-11 X15CrNiSi20-12
SS 309S 1.4833 S30908 SUS 309S 309S16 20Х23Н13 Z12CN25-20 X8CrNiSi25-21
SS 904L 1.4539 N08904 SUS 890L 904S13 03Х23Н28М3ДЗ Z2NCDU25-20 X1NiCrMoCu25-20-5
SMO 254 1.4547 S31254 Z1CNDU25-20 X1CrNiMoCuN20-18-7
17-4 PH 1.4542 S17400 SUS 630 630 07Х16Н4Б Z6CNU17-04 X5CrNiCuNb16-4
15-5 PH 1.4545 S15500 X5CrNiCuNb15-5
SS 410 1.4006 S41000 SUS 410 410S21 12Х13 Z12C13 X12Cr13
SS 420 1.4021 S42000 SUS 420J1 420S29 20Х13 Z20C13 X20Cr13
SS 430 1.4016 S43000 SUS 430 430S15 08Х17 Z8C17 X6Cr17

Stainless Steel Chemical Composition

Grade C (%) Mn (%) Si (%) P (%) S (%) Cr (%) Ni (%) Mo (%) Others
SS 304 0.08 max 2.00 max 1.00 max 0.045 max 0.030 max 18.0 – 20.0 8.0 – 11.0
SS 304L 0.03 max 2.00 max 1.00 max 0.045 max 0.030 max 18.0 – 20.0 8.0 – 12.0
SS 316 0.08 max 2.00 max 1.00 max 0.045 max 0.030 max 16.0 – 18.0 10.0 – 14.0 2.0 – 3.0
SS 316L 0.03 max 2.00 max 1.00 max 0.045 max 0.030 max 16.0 – 18.0 10.0 – 14.0 2.0 – 3.0
SS 316Ti 0.08 max 2.00 max 1.00 max 0.045 max 0.030 max 16.0 – 18.0 10.0 – 14.0 2.0 – 3.0 +Ti (5x%C min)
SS 317 0.08 max 2.00 max 1.00 max 0.040 max 0.030 max 18.0 – 20.0 11.0 – 15.0 3.0 – 4.0
SS 317L 0.03 max 2.00 max 1.00 max 0.040 max 0.030 max 18.0 – 20.0 11.0 – 15.0 3.0 – 4.0
SS 321 / 321H 0.08 / 0.04–0.10 2.00 max 1.00 max 0.045 max 0.030 max 17.0 – 19.0 9.0 – 12.0 +Ti (5x%C min)
SS 347 / 347H 0.08 / 0.04–0.10 2.00 max 1.00 max 0.045 max 0.030 max 17.0 – 19.0 9.0 – 13.0 +Nb (10x%C min)
SS 310 / 310S 0.25 / 0.08 max 2.00 max 1.50 max 0.045 max 0.030 max 24.0 – 26.0 19.0 – 22.0
SS 309 / 309S 0.20 / 0.08 max 2.00 max 1.00 max 0.045 max 0.030 max 22.0 – 24.0 12.0 – 15.0
SS 904L 0.02 max 2.00 max 1.00 max 0.045 max 0.035 max 19.0 – 23.0 23.0 – 28.0 4.0 – 5.0 +Cu 1.0 – 2.0
SMO 254 0.020 max 1.00 max 0.80 max 0.030 max 0.010 max 19.5 – 20.5 17.5 – 18.5 6.0 – 6.5 +N 0.18 – 0.22, +Cu 0.5 max
17-4 PH 0.07 max 1.00 max 1.00 max 0.035 max 0.030 max 15.0 – 17.5 3.0 – 5.0 +Cu 3.0 – 5.0, +Nb 0.15 – 0.45
15-5 PH 0.07 max 1.00 max 1.00 max 0.030 max 0.030 max 14.0 – 15.5 3.5 – 5.5 +Cu 2.5 – 4.5, +Nb 0.15 – 0.45
SS 410 0.15 max 1.00 max 1.00 max 0.040 max 0.030 max 11.5 – 13.5
SS 420 0.15 max 1.00 max 1.00 max 0.040 max 0.030 max 12.0 – 14.0
SS 430 0.12 max 1.00 max 1.00 max 0.040 max 0.030 max 16.0 – 18.0

Stainless Steel Mechanical Properties

Grade Tensile Strength (MPa) Yield Strength 0.2% Proof (MPa) Elongation (% in 50mm) Hardness (HRB)
SS 304 515 min 205 min 40 min 92 max
SS 304L 485 min 170 min 40 min 90 max
SS 316 515 min 205 min 40 min 95 max
SS 316L 485 min 170 min 40 min 95 max
SS 316Ti 550 min 240 min 40 min 95 max
SS 317 515 min 205 min 35 min 95 max
SS 317L 485 min 170 min 35 min 95 max
SS 321 / 321H 515 / 585 min 205 / 275 min 40 / 35 min 95 / 99 max
SS 347 / 347H 515 / 585 min 205 / 275 min 40 / 35 min 95 / 99 max
SS 310 / 310S 520 min 205 min 40 min 95 max
SS 309 / 309S 515 min 205 min 40 min 95 max
SS 904L 490 min 220 min 35 min 90 max
SMO 254 650 min 300 min 35 min 100 max
17-4 PH 930 – 1310 725 – 1170 10 – 20 35 – 44 HRC
15-5 PH 930 – 1310 725 – 1170 10 – 20 35 – 44 HRC
SS 410 480 min 275 min 20 min 100 max
SS 420 700 min 345 min 20 min 96 max
SS 430 450 min 205 min 22 min 88 max

Stainless Steel Types

Flange

RF, FF

Buttweld Fittings

Seamless, Welded

Forged Fittings

Socket weld, Threaded

Olets / Outlets

Weldolet, Sockolet

Stainless Steel Industries & Applications

Mining and Mineral Processing
Fire Safety and Suppression Systems
HVAC, Plumbing, and Mechanical Piping
Water Treatment and Distribution Networks
Nuclear Energy and Power Generation
Heat Exchangers and Thermal Systems
Oil, Gas, and Petrochemical Industries
Food Processing, Manufacturing, and Pharmaceutical Equipment

Stainless Steel Flange Size Chart

Flange Weights by Pressure Class and Size
Pipe Size150 #300 #600 #900 #1500 #2500 #
WNSOBLDWNSOBLDWNSOBLDWNSOBLDWNSOBLDWNSOBLD
1/2″211211222SEE 1500 # WEIGHTS544777
3/4″222333433SEE 1500 # WEIGHTS656888
1″322433444SEE 1500 # WEIGHTS988121111
1 1/2″433766878SEE 1500 # WEIGHTS131213252223
2″65597812910SEE 1500 # WEIGHTS252525423739
2 1/2″877121012181315SEE 1500 # WEIGHTS363635525556
3″1089151316231620312629484848948386
4″151317252227423741535354737373145125130
5″191520322835686368868387130130140245210225
6″241926423950818086110110115165165160380325345
8″393045675881120115140175170200275260300580485530
10″524370918112419017023026024529045543551010759301025
12″8064110140115185225200295325325415690580690152511001300
14″11090140180165250280230355400400520940NA975NANANA
16″140981802501902953903304954954256001250NA1300NANANA
18″1501302203202503954754006306806008501625NA1750NANANA
20″18016528540031550559051081083073010752050NA2225NANANA
22″2251853554653706407205901000NANANANANANANANANA
24″26022043058047579083073012501500140020253325NA3625NANANA

SS Buttweld Fittings Dimensions

NOMINAL PIPE SIZE ALL FITTINGS ALL FITTINGS ALL FITTINGS ELBOWS AND TEES 180 DEG RETURN BENDS 180 DEG RETURN BENDS 180 DEG RETURN BENDS REDUCERS CAPS
NPS O.D. at Bevel (1), (2) I.D. at End 
(1), (3), (4)
Wall Thickness (3) Centre-to-End Dimension A,B,C,M Centre-to-Centre O Back-to-Face K Alignment of Ends U Overall Length H Overall Length E
½ to 2½ 0.06 
-0.03
0.03 Not less than 87.5% of nominal thickness 0.06 0.25 0.25 0.03 0.06 0.12
3 to 3 ½ 0.06 0.06 Not less than 87.5% of nominal thickness 0.06 0.25 0.25 0.03 0.06 0.12
4 0.06 0.06 Not less than 87.5% of nominal thickness 0.06 0.25 0.25 0.03 0.06 0.12
5 to 8 0.09
-0.06
0.06 Not less than 87.5% of nominal thickness 0.06 0.25 0.25 0.03 0.06 0.25
10 to 18 0.16
-0.12
0.12 Not less than 87.5% of nominal thickness 0.09 0.38 0.25 0.06 0.09 0.25
20 to 24 0.25
-0.19
0.19 Not less than 87.5% of nominal thickness 0.09 0.38 0.25 0.06 0.09 0.25
26 to 30 0.25
-0.19
0.19 Not less than 87.5% of nominal thickness 0.12 0.19 0.38
32 to 48 0.25
-0.19
0.19 Not less than 87.5% of nominal thickness 0.19 0.19 0.38

SS Forged Fittings Dimensions

Size OD WT SR 90 Deg Elbows Centre – Face A Weight LR 90 Deg Elbows Centre – Face A Weight SR 45 Deg Elbows Centre – Face B Weight
mm inch. mm mm SCH mm kg mm kg mm kg
500 20″ 508 9.52 STD 508 93.5 762 140 318 85
12.7 X.S 508 124 762 186 318 112.5
450 18″ 457 9.52 STD 457 75.6 686 113 286 56.5
12.7 X.S 457 100 686 150 286 75
400 16″ 406.4 9.52 STD 406 59.5 610 89.3 254 45
12.7 X.S 406 78.7 610 118 254 59
350 14″ 355.6 9.52 STD 356 45.4 533 68.1 222 34.1
12.7 X.S 356 60 533 90 222 45
300 12″ 323.9 9.52 STD 305 35.4 457 53.1 190 26.6
12.7 X.S 305 46.7 457 70 190 35
250 10″ 273.9 9.27 STD 254 24.1 381 36.1 159 18.1
12.7 X.S 254 32.5 381 48.8 159 24.4
200 8″ 219.1 8.18 STD 203 13.6 305 20.4 127 10.2
12.7 X.S 203 20.9 305 30.9 127 15.5
150 6″ 168.3 7.11 STD 152.4 6.8 229 10.1 95.2 5.1
10.97 X.S 152.4 10.2 229 15.3 95.2 7.7
125 5″ 141.3 6.65 STD 127 4.8 190 6.8 79.4 3.4
9.5 X.S 127 6.5 190 10 79.4 5
100 4″ 114.3 62 STD 101.6 2.8 152.4 4.2 63.5 2.1
8.56 X.S 101.6 3.9 152.4 5.7 63.5 2.9
80 3″ 88.9 5.49 STD 76.2 1.45 114.3 2.18 50.8 1.1
7.62 X.S 76.2 1.95 114.3 2.86 50.8 1.45
65 21/2″ 73 5.16 STD 63.5 0.95 95.2 1.46 44.4 0.73
71 X.S 63.5 1.27 95.2 1.82 44.4 0.91
50 2″ 60.3 3.91 STD 50.8 0.5 76.2 0.72 34.9 0.36
5.54 X.S 50.8 0.68 76.2 1 34.9 0.5
40 11/2″ 48.3 3.68 STD 38.1 0.26 57.1 0.4 28.6 0.2
58 X.S 38.1 0.35 57.1 0.5 28.6 0.25
32 11/4″ 42.2 3.56 STD 31.75 0.18 47.6 0.28 25.4 0.14
4.85 X.S 31.75 0.24 47.6 0.39 25.4 0.2
25 1″ 33.4 3.38 STD 25.4 0.11 38.1 0.15 22.2 09
4.55 X.S 25.4 0.14 38.1 0.19 22.2 0.11
20 3/4″ 26.7 2.87 STD 28.6 08 11.1 04
3.91 X.S 28.6 0.11 11.1 05
15 1/2″ 21.3 2.78 STD 38.1 08 15.9 04
3.73 X.S 38.1 0.10 15.9 05

Major Industrial Stainless Steel Fittings & Flanges Export Countries

United Arab Emirates (UAE), Jordan, Bahrain, Kuwait, Oman, Qatar, Saudi Arabia, United States of America (USA), Singapore, Malaysia, Azerbaijan, Armenia, Georgia, Egypt, Algeria, Nigeria, South Africa, Kenya, Morocco, Ethiopia, Ghana, Tanzania, Sudan, Uganda, Angola.