Stainless Steel Flanges - Product Overview

Hars Tubes Fittings is a trusted manufacturer, supplier, and exporter of premium-quality stainless steel flanges available in a complete range of ASTM / ASME grade materials such as 304, 304L, 316, 316L, 310, 317L, 904L and Duplex / Super Duplex. We offer forged, plate, and fabricated SS flanges that are engineered for superior corrosion resistance, high durability, excellent temperature strength, and long-lasting leak-proof joint performance.

Our stainless steel flanges are widely used across Oil & Gas, Petrochemicals, Food Processing, Chemical Plants, Marine, Pharmaceuticals, Power Generation, Water Treatment, Heat Exchangers, and General Industrial Applications. Every flange is manufactured and tested as per ANSI, ASME, DIN, EN & BS international standards to ensure global quality, reliability, and unmatched performance across demanding environments.

Stainless Steel Flanges – Grades & Specifications

Specifications : ASTM A182 – F304, F304L, F316, F316L, F321, F347, 904L, 17-4PH

Types : Blind Flange (BLRF), Weld Neck Flange (WNRF), Slip-On Flange (SORF), Socket Weld Flange (SWRF), Threaded Flange (THRF), Lap Joint Flange (LJ), Orifice Flange, Long Weld Neck Flange (LWN)

Size Range : 1/2" (15 NB) to 48" (1200 NB)

Class / Pressure Rating : Class 150, 300, 600, 900, 1500, 2500 – PN6, PN10, PN16, PN25, PN40

Standards :

ASME B16.5, ASME B16.47 Series A/B, BS 4504, DIN, EN 1092-1

Face Types : Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ)

We Specialize In : Stainless Steel 304 / 316 Blind Flanges, Weld Neck Flanges, Orifice Flanges, Large-Diameter Customized SS Flanges for Marine, Chemical, Oil & Gas Industries

SS Slip on Flanges

Stainless Steel Blind Flanges

Stainless Weld Neck Flanges

Equivalent Material of Stainless Steel 304 Flanges

STANDARD	WERKSTOFF NR.	UNS	JIS	BS	GOST	AFNOR	EN
SS 304	1.4301	S30400	SUS 304	304S31	08Х18Н10	Z7CN18‐09	X5CrNi18-10

Different Types of Stainless Steel Flanges

Slip on Flanges

Blind Flanges

Weld Neck Flanges

Socket Weld Flanges

RTJ Flanges

Lap Joint Flange

Chemical Properties Of 304 Stainless Steel Flanges

Grade	C	Mn	Si	P	S	Cr	Ni
SS 304	0.08 max	2 max	0.75 max	0.045 max	0.030 max	18 – 20	8 – 11

SS Flanges Mechanical Properties

Grade	Density	Melting Point	Tensile Strength	Yield Strength (0.2%Offset)	Elongation
SS 304	8.0 g/cm3	1400 °C (2550 °F)	Psi – 75000 , MPa – 515	Psi – 30000 , MPa – 205	35 %

SS 304 Flanges Dimensions

NPS (in.)	304 Stainless Steel Flange Dimensions
NPS (in.)	Dia. of Flange (in.)	No. of Bolts	Dia. of Bolts (in.)	Dia. of Bolt Holes (in.)	Bolt Circle (in.)
1/4	3-3/8	4	1/2	0.62	2-1/4
1/2	3-1/2	4	1/2	0.62	2-3/8
3/4	3-7/8	4	1/2	0.62	2-3/4
1	4-1/4	4	1/2	0.62	3-1/8
1-1/4	4-5/8	4	1/2	0.62	3-1/2
1-1/2	5	4	1/2	0.62	3-7/8
2	6	4	5/8	0.75	4-3/4
2-1/2	7	4	5/8	0.75	5-1/2
3	7-1/2	4	5/8	0.75	6
3-1/2	8-1/2	8	5/8	0.75	7
4	9	8	5/8	0.75	7-1/2
5	10	8	3/4	0.88	8-1/2
6	11	8	3/4	0.88	9-1/2
8	13-1/2	8	3/4	0.88	11-3/4
10	16	12	7/8	1	14-1/4
12	19	12	7/8	1	17
14	21	12	1	1.12	18-3/4
16	23-1/2	16	1	1.12	21-1/4
18	25	16	1-1/8	1.25	22-3/4
20	27-1/2	20	1-1/8	1.25	25
24	32	20	1-1/4	1.38	29-1/2

SS 304 Flange Weight Chart

Pipe Normal Diameter (inch)		Outer diameter Flange	Thickness Of Flange Minimum	Diameter of Hub	Diameter of Raised Face	Length Hub.Y	Thread Length	Diameter of Bolt Circle	Diameter of Bolt Holes	Number of Bolts	Diameter of Bolts (inch)	KG	LB
1/2"	15	89.00	11.20	30.20	35.10	15.70	15.70	60.50	15.80	4	1/2"	0.4	0.9
3/4"	20	98.50	12.70	38.10	42.90	15.70	15.70	69.90	15.80	4	1/2"	0.7	1.5
1"	25	108.00	14.20	49.30	50.80	17.50	17.50	79.30	15.80	4	1/2"	0.8	1.8
1-1/4"	32	117.50	15.70	58.70	63.50	20.60	20.60	88.90	15.80	4	1/2"	1.2	2.6
1-1/2"	40	127.00	17.50	65.00	73.20	22.40	22.40	98.60	15.80	4	1/2"	1.5	3.3
2"	50	152.50	19.10	77.70	91.90	25.40	25.40	120.70	19.10	4	5/8"	2.3	5.1
2-1/2"	65	178.00	22.40	90.40	104.60	28.40	28.40	139.70	19.10	4	5/8"	3.7	8.1
3"	80	190.50	23.90	108.00	127.00	30.20	30.20	152.40	19.10	4	5/8"	4.1	9
3-1/2"	90	216.00	23.90	122.20	139.70	31.80	31.80	177.80	19.10	8	5/8"	5.1	11.2
4"	100	228.50	23.90	134.90	157.20	33.30	33.30	190.50	19.10	8	5/8"	5.9	13
5"	125	254.00	23.90	163.60	185.70	36.60	36.60	215.90	22.40	8	3/4"	7	15.4
6"	150	279.50	25.40	192.00	215.90	39.60	39.60	241.30	22.40	8	3/4"	8.4	18.5
8"	200	343.00	28.40	246.10	269.70	44.50	44.50	298.50	22.40	8	3/4"	13	28.6
10"	250	406.50	30.20	304.80	323.90	49.30	49.30	362.00	25.40	12	7/8"	18	39.5
12"	300	482.50	31.80	365.30	381.00	55.60	55.60	431.80	25.40	12	7/8"	29	64
14"	350	533.50	35.10	400.10	412.80	57.20	57.20	476.30	28.50	12	1"	39	86
16"	400	597.00	36.60	457.20	469.90	63.50	63.50	539.80	28.50	16	1"	47	103
18"	450	635.00	39.60	505.00	533.40	68.30	68.30	577.90	31.80	16	1 1/8"	57	126
20"	500	698.50	42.90	558.80	584.20	73.20	73.20	635.00	31.80	20	1 1/8"	76	167
24"	600	813.00	47.80	663.40	692.20	82.60	82.60	749.30	35.10	20	1 1/4"	97	214

UNS S30400 Flange Pressure Rating Chart

ASME	Pressure Temperature Ratings For Stainless Steel 304 Flanges
Temperature °F	Class 150	Class 300	Class 400	Class 600	Class 900	Class 1500	Class 2500
-20 to 100	275	720	960	1440	2160	3600	6000
200	230	600	800	1200	1800	3000	5000
300	205	540	720	1080	1620	2700	4500
400	190	495	660	995	1490	2485	4140
500	170	465	620	930	1395	2330	3880
600	140	435	580	875	1310	2185	3640
650	125	430	575	860	1290	2150	3580
700	110	425	565	850	1275	2125	3540
750	95	415	555	830	1245	2075	3460
800	80	405	540	805	1210	2015	3360
850	65	395	530	790	1190	1980	3300
900	50	390	520	780	1165	1945	3240
950	35	380	510	765	1145	1910	3180
1000	20	320	430	640	965	1605	2675
1050	20	310	410	615	925	1545	2570
1100	20	255	345	515	770	1285	2145
1150	20	200	265	400	595	995	1655
1200	20	155	205	310	465	770	1285
1250	20	115	150	225	340	565	945
1300	20	85	115	170	255	430	715
1350	20	60	80	125	185	310	515
1400	20	50	65	95	145	240	400
1450	15	35	45	70	105	170	285
1500	10	25	35	55	80	135	230

Stainless Steel Flanges