5 1/4" OD Flanges | McMaster-Carr

Filter by

System of Measurement

Pipe Size

Pressure Class

Material

Fitting Connection

Fitting Type

Bolt Circle Diameter

Flanged Connection Surface

Flat

Raised

Pipe Schedule

Pipe Material

Polypropylene

Stainless Steel

Steel

Number of Bolt Holes

For Use With

Connects To

Bolt Hole Diameter

For Fitting Schedule

Fitting Material

Specifications Met

Thread Type

Maximum Pressure @ Temperature

Shape

REACH

RoHS

Export Control Classification Number (ECCN)

2B999

EAR99

U.S.–Mexico–Canada Agreement (USMCA) Qualifying

Yes

DFARS Specialty Metals

Exempt

Forward

How can we improve?

23 Products

About Pipe and Fittings

Measure your pipe and fittings to identify their pipe size, thread size, schedule, and thread type. Then, find compatible components.

Fitting Type

Cap

Cover a pipe end to seal it

4 products

Performance

Chemical Resistant

Stay strong when exposed to acids, bases, and other harsh chemicals

15 products

Performance

Corrosion Resistant

Withstand exposure to moisture and mild chemicals

13 products

High Purity

Polished to an ultra-smooth finish that won't leach contaminants

2 products

High-Pressure Stainless Steel Unthreaded Pipe Flanges

Use these heavy duty forged flanges for high-pressure applications. Bolt two flat-surface flanges or two raised-surface flanges of same size together with a gasket (sold separately) to create an access point in a pipe line.

Forged Flanges


Butt Weld	Slip-On	Socket-Connect

Forged flanges have better strength than cast flanges.

Butt-Weld Fitting Connection—Butt-weld flanges are also known as weld-neck flanges; the flange neck has a beveled end that, when flush to pipe, creates a trough for a strong weld.

Slip-on-Weld Fitting Connection—Slip-on weld flanges have no internal stop; slide a pipe through the flange and weld on both sides.

304/304L Stainless Steel—Flanges hold up in humid, damp, and washdown environments but will corrode if exposed to salt water or chemicals.

316/316L Stainless Steel—Flanges are the most corrosion resistant. They stand up to wet environments, just like 304 stainless steel flanges, but unlike 304 stainless steel, they will not corrode from salt water, chlorine solutions, and chemicals.

	Pipe Size		Dash Size					Bolt Hole						304/304L Stainless Steel		316/316L Stainless Steel
	(A)	(B)	(A)	(B)	Flanged Connection Surface (B)	Flange OD	For Bolt Dia.	Dia.	No. Of	Bolt Circle Dia.	Pressure Class	Max. Pressure @ Temp.	Max. Steam Pressure @ Temp.		Each		Each
Butt Weld



		1 1/4	1 1/4	20	20	Raised	5 1/4"	5/8"	0.75"	4	3 7/8"	300	600 psi @ 72° F	415 psi @ 360° F	4448T289	0000000	4452T299	0000000


		Slip-On Weld Female



				1 1/4	1 1/4	20	20	Raised	5 1/4"	5/8"	0.75"	4	3 7/8"	300	600 psi @ 72° F	300 psi @ 360° F	4448T254	00000	4452T264	000000


				Socket-Connect Female



						1 1/4	1 1/4	20	20	Raised	5 1/4"	5/8"	0.75"	4	3 7/8"	300	600 psi @ 72° F	300 psi @ 360° F	4448T267	000000	4452T277	000000

Forged Blind Flanges


Front	Raised Surface on Back

Forged flanges have better strength than cast flanges.

304/304L Stainless Steel—Flanges hold up in humid, damp, and washdown environments but will corrode if exposed to salt water or chemicals.

						Bolt Hole						304/304L Stainless Steel		316/316L Stainless Steel
	Pipe Size	Dash Size	Flanged Connection Surface	Flange OD	For Bolt Dia.	Dia.	No. Of	Bolt Circle Dia.	Pressure Class	Max. Pressure @ Temp.	Max. Steam Pressure @ Temp.		Each		Each
Flanged



		1 1/4	20	Raised	5 1/4"	5/8"	0.75"	4	3 7/8"	300	600 psi @ 72° F	300 psi @ 360° F	4448T278	000000	4452T288	0000000


		1 1/4	20	Raised	5 1/4"	5/8"	0.75"	4	3 7/8"	600	1,200 psi @ 72° F	840 psi @ 400° F	1538N94	000000	———	0

High-Pressure Stainless Steel Threaded Pipe Flanges

Forged for high strength, these heavy duty flanges can handle high-pressure applications. They are also known as ANSI flanges. Bolt two same-size flanges together with a gasket (sold separately) to create an access point within a line.

Forged Flanges


Front	Raised Surface on Back

Forged flanges have better strength than cast flanges.

304/304L Stainless Steel—Flanges hold up in humid, damp, and washdown environments but will corrode if exposed to salt water or chemicals.

	Pipe Size		Dash Size					Bolt Hole						304/304L Stainless Steel		316/316L Stainless Steel
	(A)	(B)	(A)	(B)	Flanged Connection Surface (B)	Flange OD	For Bolt Dia.	Dia.	No. Of	Bolt Circle Dia.	Pressure Class	Max. Pressure @ Temp.	Max. Steam Pressure @ Temp.		Each		Each
NPT Female



		1 1/4	1 1/4	20	20	Raised	5 1/4"	5/8"	0.75"	4	3 7/8"	300	600 psi @ 72° F	300 psi @ 300° F	7977K14	000000	7469T34	0000000


		1 1/4	1 1/4	20	20	Raised	5 1/4"	5/8"	0.75"	4	3 7/8"	600	1,200 psi @ 72° F	840 psi @ 400° F	1441N28	000000	1501N24	000000

High-Pressure Iron and Steel Unthreaded Pipe Flanges

Forged for extra strength, these heavy duty flanges can withstand high-pressure applications. Bolt two flat-surface flanges or two raised-surface flanges of the same size together with a gasket (sold separately) to create an access point in a pipe line.

Forged Flanges


Butt Weld (Front)	Butt Weld (Raised Surface on Back)	Slip-On Weld (Front)	Slip-On Weld (Raised Surface on Back)

Socket Connect (Front)	Socket-Connect (Raised Surface on Back)	Stub-End (Front)	Stub-End (Flat Surface on Back)

Forged flanges have better strength than cast flanges.

Butt-Weld Fitting Connection—Butt-weld flanges are also known as weld-neck flanges; the flange neck has a beveled end that, when flush to pipe, creates a trough for a strong weld.

Slip-on-Weld Fitting Connection—Slip-on weld flanges have no internal stop; slide a pipe through the flange and weld on both sides.

Stub-End Fitting Connection—Stub-end flanges are also known as lap-joint flanges. Use them with a stub-end straight adapter (not included). The stub-end straight adapter slides into the flange and welds to pipe (not the flange). Since the flange isn’t welded to the pipe, it can be disconnected easily for frequent cleaning and inspecting.

	Pipe Size		Dash Size					Bolt Hole
	(A)	(B)	(A)	(B)	Flanged Connection Surface (B)	Flange OD	For Bolt Dia.	Dia.	No. Of	Bolt Circle Dia.	Pressure Class	Material	Max. Pressure @ Temp.	Max. Steam Pressure @ Temp.		Each
Butt Weld



		1 1/4	1 1/4	20	20	Raised	5 1/4"	5/8"	3/4"	4	3 7/8"	300	Steel	600 psi @ 72° F	300 psi @ 300° F	6806K299	000000


		Slip-On Weld Female



				1 1/4	1 1/4	20	20	Raised	5 1/4"	5/8"	3/4"	4	3 7/8"	300	Steel	600 psi @ 72° F	300 psi @ 300° F	6806K279	00000


				Socket-Connect Female



						1 1/4	1 1/4	20	20	Raised	5 1/4"	5/8"	3/4"	4	3 7/8"	300	Steel	600 psi @ 72° F	300 psi @ 300° F	6806K289	00000


						Stub-End Female



								1 1/4	1 1/4	20	20	Flat	5 1/4"	5/8"	3/4"	4	3 7/8"	300	Steel	600 psi @ 72° F	300 psi @ 300° F	6806K329	00000

Forged Blind Flanges


Front	Raised Surface on Back

Forged flanges have better strength than cast flanges.

						Bolt Hole
	Pipe Size	Dash Size	Flanged Connection Surface	Flange OD	For Bolt Dia.	Dia.	No. Of	Bolt Circle Dia.	Pressure Class	Material	Max. Pressure @ Temp.	Max. Steam Pressure @ Temp.		Each
Flanged



		1 1/4	20	Raised	5 1/4"	5/8"	3/4"	4	3 7/8"	300	Steel	600 psi @ 72° F	300 psi @ 300° F	6806K319	000000

Stub-End Straight Adapters

Straight Adapter

Stub-end straight adapters are used with flanges. Slide a flange onto the stub end and weld the stub end to pipe (not the flange). Since the flange isn’t welded to the pipe, it can be disconnected easily, which creates an access point for frequent cleaning and inspecting.

Pipe Size	Flange OD	Construction	Pipe Schedule	Finished Material		Each
1 1/4	2 1/2"	Seamless	80	Steel	4981T241	0000000

High-Pressure Iron and Steel Threaded Pipe Flanges

With better strength than our low-pressure steel flanges, these are for use in high-pressure applications. Bolt two same-size flanges together with a gasket (sold separately) to create an access point within a line. Flanges are also known as Pressure Class 300 or Pressure Class 600 flanges. Use in noncorrosive environments.

Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.

Flanges


Front	Raised Surface on Back

	Pipe Size					Bolt Hole
	(A)	(B)	Flanged Connection Surface (B)	Flange OD	For Bolt Dia.	Dia.	No. Of	Bolt Circle Dia.	Pressure Class	Material	Max. Pressure @ Temp.	Max. Steam Pressure @ Temp.		Each
NPT Female



		1 1/4	1 1/4	Raised	5 1/4"	5/8"	3/4"	4	3 7/8"	300	Steel	600 psi @ 72° F	300 psi @ 300° F	6806K123	000000

High-Purity Polypropylene Pipe Flanges for Drinking Water

The inside of these flanges won’t leach contaminants into your line or accumulate particles—they’re polished to an ultra-smooth 12 Ra finish, which also makes them easy to clean. Made of polypropylene, they resist organic solvents, acids, and alkalis better than CPVC pipe flanges. Bolt two same-size flanges together with a gasket (not included) to create an access point in your line. These flanges meet NSF/ANSI 61 for use with drinking water, and they’re FDA compliant for direct contact with food. They also meet ASTM requirements for material and performance, and ISO requirements for dimensions.

Also known as lap-joint flanges, they connect to pipe with stub-end straight adapters (not included). Slide the stub end adapter into your flange and weld to your pipe with socket fusion. Since the flange isn’t welded to the pipe, it can be disconnected easily for cleaning and inspecting.

Warning: Never use plastic pipe fittings, flanges, and pipe with compressed air or gas.

Flanges

Flange with Straight

Adapter

NSF/ANSI 61—To adhere to safety standards for drinking water systems, use pipe that meets NSF/ANSI 61.

	Pipe Size					Bolt Hole
	(A)	(B)	Flanged Connection Surface (B)	Flange OD	For Bolt Dia.	Dia.	No. Of	Bolt Circle Dia.	Pressure Class	Material	Color	Max. Pressure @ Temp.	Food Industry Std.		Each
Stub End



		1 1/2	1 1/2	Flat	5 1/4"	1/2"	5/8"	4	3 7/8"	150	Polypropylene	Light Gray	150 psi @ 72° F	FDA Compliant 21 CFR 177.1520, FDA Compliant 21 CFR 178.3297, NSF/ANSI 61	5352N14	000000

Stub-End Straight Adapters

Straight

Adapter

Pipe Size	Wall Thk.	Flange OD	Finished Material		Each
1 1/2	0.195"	3 15/64"	Polypropylene	5381N088	000000

High-Pressure Galvanized Iron and Steel Threaded Pipe Flanges

A galvanized finish gives these flanges fair corrosion resistance. Also known as Pressure Class 300 flanges, they can withstand medium-pressure applications. Bolt two same-size flanges together with a gasket (sold separately) to create an access point within a line.

Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.

Flanges


Front	Raised Surface on Back

	Pipe Size					Bolt Hole
	(A)	(B)	Flanged Connection Surface (B)	Flange OD	For Bolt Dia.	Dia.	No. Of	Bolt Circle Dia.	Pressure Class	Material	Max. Pressure @ Temp.	Max. Steam Pressure @ Temp.		Each
NPT Female



		1 1/4	1 1/4	Raised	5 1/4"	3/4"	3/4"	4	3 7/8"	300	Galvanized Steel	600 psi @ 72° F	Not Rated	1733N14	0000000