Brass Flanges | UNS C36000 | IS 319

Brass flanges are mechanical fittings made from copper-zinc alloys that pair good machinability with reliable corrosion resistance. That combination makes them a common pick for plumbing, marine, HVAC, and light industrial piping. We produce them in companion (lap joint), threaded, blind, slip-on, and weld-neck forms, which gives you re-usable joints that simplify assembly, inspection, and maintenance while holding a solid seal with the right gaskets and fasteners. PM Industries manufactures, supplies, and stocks brass flanges in a range of grades, sizes, and pressure classes.

Common brass grades include free-machining and dezincification-resistant alloys such as C36000 (UNS C36000 / CZ121) for general-purpose parts, along with leaded or low-lead variants where you need extra machinability or potable-water compatibility. In service, brass flanges resist atmospheric and freshwater corrosion and bring useful antimicrobial properties, which helps in sanitary plumbing and beverage systems. They are less suited than stainless steel to highly acidic or strongly oxidizing media, so grade choice matters with the service in mind.

On dimensions, brass flanges are supplied to standard pressure classes such as Class 125/150, with bolt-circle, hole-pattern, and thickness details set by common flange standards for each nominal pipe size. That keeps them interchangeable with mating fittings and pipe flanges. We offer standard and extra-heavy variants for higher mechanical loads or thicker gasket faces, and blind flanges for system termination and pressure testing.

Fabrication runs from casting for complex shapes to forging or machining for higher-strength or precision parts. Machining gives tight control over the bore, face finish, and bolt-hole geometry, which improves sealing with compressed gaskets. When picking a brass flange, engineers weigh operating pressure and temperature, exposure to dezincifying media, galvanic compatibility with nearby metals, and potable-water rules that may cap lead content. The right alloy, protective coatings, or isolation measures keep those concerns in check.

For moderate-duty piping where machinability, conductivity, or appearance matter alongside dependable sealing, brass flanges give you a strong balance of workability, corrosion resistance, and finish. PM Industries holds stock ready to ship, with certification and test documentation on every order. Tell us your flange type, size, class, and grade, and we will quote it.

Specification Brass Flange

Standards	ANSI/ASME B16.5, B16.48, ANSI Flanges, GOST Flanges, DIN Flanges, EN-1092, B16.47 Series A & B, ASME Flanges, EN Flanges, AWWA Flanges, BS Flanges.
JIS Standard	5K, 10 K, 16 K 20 K, 30 K, 40 K, 63 K
DIN FLANGES	DIN 2527, 2627, 2631, 2656, 2576, 2673, 2629, 2628, 2566, 2641, 2637, 2655, 2634, 2636, 2632, 2633, 2638, 2642, 2573, 2635.
Pressure Rating	Class 150 LBS, 300 LBS, 600 LBS, 900 LBS, 1500 LBS, 2500 LBS
Types	Threaded, Plate, Screwed, Forged.
Supporting material	Gasket, Ring Joint, Flange Bolts
Size range	1/2" (15 NB) to 48" (1200NB) DN10~DN5000
Production technique	Forged, machined and Heat treated
Available Flange Type	Weld Neck Flanges, RTJ Flanges, Slip On Flanges, Spectacle Blind Flanges, Flanges Gaskets, Square Flanges, Standard Insert Flanges, High Hub Blinds Flanges, Flat Flanges, forged flanges, Weldo / Nipo Flanges, Jacket Insert Flanges, Tongue groove Flanges, Blind Flanges, Socket Weld Flanges, Large diameter Flanges, Long Weld Neck Flanges, Spacer Blinds, SWRF Flanges, SORF Flanges, Angle Face Rings Flanges, Spades Ring Spacers Flanges, WNRF Flanges, Screwed Flanges, Insert Flanges, flanges bolts, cf flange, Lap Joint Flanges, ASME B16.36 Orifice Flanges, Plate Flange, Expander Flanges, Ring Type Joint Flanges, Loose Flanges, Reducing Flanges, puddle flange, Threaded Flanges, blank flange, vacuum flange.
Connect Type/ Flange Face Type	Ring Type Joint (RTJ), Flat Face (FF), Tongue & Groove, Small Male-Female (SMF), Lap-Joint Face (LJF), Raised Face (RF), Large Male-Female (LMF), Small Tongue.
Custom design	As per your drawing
Test	Direct-reading Spectrograph, X-ray detector, UItrasonic flaw detector, Magnetic particle detector, Hydrostatic testing machine.
Origin	Indian / USA / Korean / West Europe / Japan
Pressure Class	PN 6 TO PN 100
Thickness	Normal Pipe Size ≤ 18
Bore Diameter	Normal Pipe ≤ 10
High Temperature	Above 200°C (400°F) For Class 150 Or Above 400°C (750°F)
Low Temperature	Above -29 Degree C (−20°F)
Coating/Surface Treatment:	Zinc Plated, Anti-rust Paint, Oil Black Paint, Yellow Transparent, Cold and Hot Dip Galvanized.
European/African/Russian Standard Flanges	Available
Gaskets Types	Full Face, Metallic Ring, Flat Ring Gasket
Marking Standard	Name of Manufacturer
	Schedule
	Type of Flange Facing
	Pressure Class
	Nominal Pipe Size, etc
Test Certificates	EN 10204/3.1B, NACE MR0103, NACE MR0175
	Raw Materials Certificate
	100% Radiography Test Report
	Third Party Inspection Report, etc

Flange Type Available

Brass Flanges Dimensions Class-150

Nominal Pipe Size NPS (inches)	Class 150
	Diameter of Flange (inches)	No. of Bolts	Diameter of Bolts (inches)	Diameter of Bolt Holes (inches)	Bolt Circle (inches)
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

ASME/ANSI B16.5 Brass Flanges Dimensions Class-400

Nominal Pipe Size NPS (inches)	Class 400
	Diameter of Flange (inches)	No. of Bolts	Diameter of Bolts (inches)	Diameter of Bolt Holes (inches)	Bolt Circle (inches)
1/4	3-3/8	4	1/2	0.62	2-1/4
1/2	3-3/4	4	1/2	0.62	2-5/8
3/4	4-5/8	4	5/8	0.75	3-1/4
1	4-7/8	4	5/8	0.75	3-1/2
1-1/4	5-1/4	4	5/8	0.75	3-7/8
1-1/2	6-1/8	4	3/4	0.88	4-1/2
2	6-1/2	8	5/8	0.75	5
2-1/2	7-1/2	8	3/4	0.88	5-7/8
3	8-1/4	8	3/4	0.88	6-5/8
3-1/2	9	8	7/8	1	7-1/4
4	10	8	7/8	1	7-7/8
5	11	8	7/8	1	9-1/4
6	12-1/2	12	7/8	1	10-5/8
8	15	12	1	1.12	13
10	17-1/2	16	1-1/8	1.25	15-1/4
12	20-1/2	16	1-1/4	1.38	17-3/4
14	23	20	1-1/4	1.38	20-1/4
16	25-1/2	20	1-3/8	1.5	22-1/2
18	28	24	1-3/8	1.5	24-3/4
20	30-1/2	24	1-1/2	1.62	27
24	36	24	1-3/4	1.88	32

Brass Flange Pressure Class/ Rating

ASME/ANSI B 16.5	Lap Joint Flange, Ring Type Joint Flange, Threaded Flange, Blind Flange, High Hub Blind Flange, Socket Weld Flange, Slip on Flange, Welding Neck Flange.
PRESSURE CLASS	150, 300, 400, 600, 900, 1500, 2500
ASME/ANSI B 16.47	Blind Flange [Series A & B], Welding Neck Flange.
PRESSURE CLASS	75, 150, 300, 400, 600, 900
ASME/ANSI B 16.36	Slip on Flange, Threaded Flange, Welding Neck Flange.
PRESSURE CLASS	300, 400, 600, 900, 1500, 2500
BS 4504 SEC 3.1	Plate Flange, Welding Neck Flange, Hubbed Slip on Flange, Lapped Pipe End Flange, Loose Plate With Weld Neck Flange, Hubbed Threaded Flange, Blank Flange, Loose Plate Flange.
PRESSURE CLASS	PN 2.5 TO PN 40
BS 4504[PART 1]	Blank Flange, Loose Plate With Weld On Plate Collar, Welding Neck Flange, Plate Flange, Hubbed Slip-On Hubbed Threaded.
PRESSURE CLASS	PN 2.5 TO PN 400
BS 1560 BOSS	Blind Flange, Screwed Boss Flange, Welding Neck Flange,Slip-On Flange, Lapped Flange, Socket Welding Flange.
PRESSURE CLASS	150, 300, 400, 600, 900, 1500, 2500
BS10	Screwed Boss Flange, Plate Slip-On Flange, Slip-On Boss Flange, Blind Flange, Welding Neck Flange.
TABLE	D, E, F, H
DIN FLANGES	DIN 2527, 2632, 2635, 2673, 2566, 2655, 2631, 2627, 2634, 2576, 2636, 2629, 2633, 2573, 2656, 2638, 2637, 2642, 2641, 2628
PRESSURE CLASS	PN 6 TO PN 100