Stainless Steel 309 Flanges, SS 310 Flanges Supplier

SS 309, 310, and 310S flanges are engineered from high-alloy austenitic stainless steels specifically formulated to withstand extreme heat and oxidative environments. These flanges are ideal for high-temperature structural applications due to their superior chromium and nickel content, which enhances their ability to resist scaling and corrosion in sustained elevated-temperature operations. SS 309 offers a balance of strength and heat resistance, while SS 310 provides enhanced oxidation resistance at temperatures up to 1150°C. SS 310S, the low-carbon version of SS 310, delivers better weldability and reduced carbide precipitation, making it ideal for welded pressure vessels and heat exchanger components. These flanges are available in a variety of types, such as weld neck, slip-on, socket weld, blind, and threaded configurations, and are manufactured in accordance with global industrial standards, including ANSI, ASTM, DIN, and JIS.

Technical Overview

The defining characteristic of SS 309/310/310S flanges lies in their metallurgical composition and performance under thermal stress. SS 309 contains approximately 23% chromium and 13% nickel, which offers solid resistance to oxidation and sulfidation. SS 310, with higher chromium (25%) and nickel (20%) content, provides superior high-temperature strength and resistance to scaling, even in intermittent service at temperatures as high as 1150°C. SS 310S, with reduced carbon content, minimizes the risk of sensitization during welding, enhancing its utility in applications where structural integrity must be preserved after fabrication.

Mechanically, these grades offer excellent tensile strength, toughness, and structural reliability under pressure and thermal expansion. Their resistance to thermal fatigue and creep deformation makes them especially valuable in equipment subject to regular heating and cooling cycles. These flanges can be fabricated using standard machining and welding techniques and retain their dimensional stability and surface integrity even in chemically aggressive environments. Their ability to maintain performance in high-stress, high-heat environments places them among the top choices for heavy-duty industrial flange requirements.

Applications & Industry Use

309/310/310S Stainless Steel flanges are integral to industries that operate under demanding thermal and corrosive conditions. Common application sectors include petrochemical processing, thermal power generation, cement production, steel manufacturing, furnaces, incinerators, and high-temperature exhaust systems. They are widely employed in heat treatment trays, furnace doors, recuperators, radiant tubes, and high-temperature ductwork, where failure is not an option. Their superior heat tolerance and structural integrity enable long service life, reducing maintenance frequency and enhancing operational efficiency.

These flanges are supplied extensively across regions with significant industrial activity and extreme climate challenges, including India, the United Arab Emirates (UAE), the Kingdom of Saudi Arabia (KSA), Kuwait, Qatar, the Sultanate of Oman, Iran, and Iraq. These regions rely heavily on high-performance flanged components to meet the rigorous demands of infrastructure development, oil refining, gas processing, and thermal plant operations. With a reputation for durability and precision, SS 309/310/310S flanges continue to serve as a reliable solution for clients seeking resilient and cost-effective piping connections in high-temperature service environments.

309/310/310S Stainless Steel Flanges Equivalent Grades

STANDARD	UNS	WNR.	AFNOR	EN	JIS	BS	GOST
SS 309	S30900	1.4828	-	-	SUS 309	-	-
SS 310	S31000	1.4841 / 1.4307	-	X15CrNi25-20	SUS 310	310S24	20Ch25N20S2
SS 310S	S31008	1.4845	-	-	SUS 310S	-	20Ch23N18

SS 309/310/310S Threaded Flanges

ASME SA213 SS 304L /304H Seamless Tube, ASTM A213 Stainless Steel 304 Seamless Tubing, DIN 1.4301 / 1.4307 Seamless Tubes, UNS S30403 / S30409 Seamless Tube

SS 309/310/310S Socket Weld Flanges

Stainless Steel 304 Seamless Pipes, UNS S30400 / S30403 / S30409 Seamless Pipes, DIN 1.4301 Seamless Pipes, ASME SA 312 SS TP304H Seamless Piping

SS 309/310/310S Lap Joint Flanges

ASME SA213 SS 304L /304H Seamless Tube, ASTM A213 Stainless Steel 304 Seamless Tubing, DIN 1.4301 / 1.4307 Seamless Tubes, UNS S30403 / S30409 Seamless Tube

SS 309/310/310S Threaded Flanges

DIN 1.4301 Welded Tubing, UNS S30400 Welded Tube, ASME SA 213 Stainless Steel 304L Welded Tubes, ASTM A213 304H SS Welded Tubes

SS 309/310/310S Socket Weld Flanges

ASME SA358 304 SS EFW Pipes, ASTM A358 TP304H Stainless Steel EFW Pipe, SS UNS S30400/ S30403/ S30409 EFW Pipes, SS DIN 1.4301 / 1.4306 EFW Pipes

SS 309/310/310S Lap Joint Flanges

UNS S30400 ERW Pipes, Stainless Steel 304 ERW Tubing, ASTM A213 TP304L Stainless Steel ERW Tubes, ASME SA 312 SS 304H Pipe

SS 309/310/310S Ring Type Joint Flange

ASME SA358 304 SS EFW Pipes, ASTM A358 TP304H Stainless Steel EFW Pipe, SS UNS S30400/ S30403/ S30409 EFW Pipes, SS DIN 1.4301 / 1.4306 EFW Pipes

SS 309/310/310S Orifice Flanges

UNS S30400 ERW Pipes, Stainless Steel 304 ERW Tubing, ASTM A213 TP304L Stainless Steel ERW Tubes, ASME SA 312 SS 304H Pipe

SS 309/310/310S Long Weld Neck Flanges

UNS S31008 Long Weld Neck Flanges, Stainless Steel 1.4845 Long Weld Neck Flanges, ASTM A182 F310 Stainless Steel Long Weld Neck Flanges, ASME SA 182 SS 310S Long Weld Neck Flanges

SS 309/310/310S Spectacle Blind Flanges

UNS S31000 Spectacle Blind Flanges, ANSI / ASME B16.5 Stainless Steel 309 Spectacle Blind Flanges, ASTM A182 F310 Stainless Steel Spectacle Blind Flanges, SA 182 SS 310S Spectacle Blind Flanges

SS 309/310/310S Forged Flanges

UNS S31008 Forged Flanges, B16.5 Stainless Steel 309 Forged Flanges, ASTM A182 F310 Stainless Steel Forged Flanges, ASME SA 182 SS 310S Forged Flanges

SS 309/310/310S Plate Flanges

UNS S30900 Plate Flanges, ANSI B16.5 Stainless Steel 309 Plate Flanges, ASTM A182 F310 Stainless Steel Plate Flanges, ASME SA 182 SS 310S Plate Flanges

Stainless Steel Flanges Specification :

ASTM A182 / ASME SA182

Dimension Standard :

ANSI/ASME B16.5, B 16.47 Series A & B, B16.48, BS4504, BS 10, EN-1092, DIN, etc.

Standard :

ANSI Flanges, ASME Flanges, BS Flanges, DIN Flanges, EN Flanges, etc.

Size :

1/2" (15 NB) to 48" (1200NB)

Class / Pressure :

150#, 300#, 600#, 900#, 1500#, 2500#, PN6, PN10, PN16, PN25, PN40, PN64 etc.

Flange Face Type :

Flate Face (FF), Raised Face (RF), Ring Type Joint (RTJ)

DIN Flanges :

DIN 2527, 2566, 2573, 2576, 2641,2642, 2655, 2656, 2627, 2628, 2629, 2631, 2632, 2633, 2634, 2635, 2636, 2637,2638, 2673.

JIS Flanges :

JIS B2220 5K, JIS B2220 10K, JIS B2220 16K, JIS B2220 20K

BS Flanges :

BS4504 PN 6, BS 4504 PN 10, BS4504 PN 16, BS4504 PN 25, BS4504 PN 40, BS 4504 PN 64, BS 4504 PN 100, BS 4504 PN 160, BS 4504 PN 250, BS 10, BS Table D, BS Table E, BS Table F, BS Table H.

Chemical Composition of Stainless Steel 309/310/310S Flanges

	C	Mn	Si	P	S	Cr	Ni	Fe
309	0.2 max	2.0 max	1.0 max	0.045max	0.03max	22 24	12-15	Balance
310	0.25 max	2.0 max	1.50 max	0.045max	0.03max	24-26	min: 8.0 max: 12.0	Balance
310S	0.08 max	2.00 max	1.50 max	0.045	0.03	24-26	19-22	Balance