Steel Duct Flanges | McMaster-Carr

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174 Products

Duct Flanges

Mount flanges to air handlers and HVAC equipment to start a run of duct. They also create a secure joint between sections of duct—attach a flange to each piece. Also known as angle rings.

With Mounting Holes—Ready to install, these flanges secure with screws.

Without Mounting Holes—Drill your own holes or weld into place.

Steel—Strong for a long life, these steel flanges can be painted or coated. Unless it’s finished, steel is best for dry environments.

Galvanized Steel—Corrosion resistant and affordable, galvanized steel is the most commonly used ductwork material.

Corrosion-Resistant 304 Stainless Steel—The most corrosion-resistant metal duct we sell. It won’t rust or degrade in systems that exhaust chemical fumes or vent heat from industrial ovens and dryers.

				Flange		Mounting
	Duct Size	ID	Overall Dp.	Ht.	Thk.	Fasteners Included	No. of Holes	Hole Dia.		Each
With Mounting Holes







				Steel

				3	3 1/16"	1"	1"	1/8"	No	6	9/32"	1764K41	00000


				3 1/2	3 9/16"	1"	1"	9/64"	No	6	9/32"	1764K84	00000
				4	4 1/16"	1"	1"	1/8"	No	6	9/32"	1764K42	00000
				4 1/2	4 9/16"	1"	1"	9/64"	No	6	9/32"	1764K85	00000
				5	5 1/16"	1"	1"	1/8"	No	6	9/32"	1764K43	00000
				5 1/2	5 9/16"	1"	1"	9/64"	No	6	9/32"	1764K86	00000
				6	6 1/8"	1 1/4"	1 1/4"	1/8"	No	6	3/8"	1764K11	00000
				7	7 1/8"	1 1/4"	1 1/4"	1/8"	No	6	3/8"	1764K12	00000
				8	8 1/8"	1 1/4"	1 1/4"	1/8"	No	6	3/8"	1764K23	00000
				9	9 1/8"	1 1/4"	1 1/4"	1/8"	No	6	3/8"	1764K25	00000
				10	10 1/8"	1 1/4"	1 1/4"	1/8"	No	6	3/8"	1764K27	00000


				11	11 1/8"	1 1/4"	1 1/4"	1/8"	No	6	3/8"	1764K88	00000
				12	12 1/8"	1 1/2"	1 1/2"	1/8"	No	8	7/16"	1764K32	00000
				13	13 1/8"	1 1/2"	1 1/2"	1/8"	No	8	7/16"	1764K34	00000
				14	14 1/8"	1 1/2"	1 1/2"	1/8"	No	8	7/16"	1764K37	00000
				15	15 1/8"	1 1/2"	1 1/2"	1/8"	No	8	7/16"	1764K38	00000
				16	16 1/8"	1 1/2"	1 1/2"	3/16"	No	8	7/16"	1764K39	00000
				17	17 1/8"	1 1/2"	1 1/2"	3/16"	No	8	7/16"	1764K87	00000
				18	18 1/8"	1 1/2"	1 1/2"	3/16"	No	8	7/16"	1764K44	00000
				19	19 1/8"	1 1/2"	1 1/2"	3/16"	No	12	7/16"	1764K991	00000
				20	20 1/8"	1 1/2"	1 1/2"	3/16"	No	12	7/16"	1764K45	00000


				21	21 1/8"	1 1/2"	1 1/2"	3/16"	No	12	7/16"	1764K89	00000
				22	22 1/8"	1 1/2"	1 1/2"	3/16"	No	12	7/16"	1764K46	00000
				23	23 1/8"	1 1/2"	1 1/2"	3/16"	No	12	7/16"	1764K91	00000
				24	24 1/8"	1 1/2"	1 1/2"	3/16"	No	12	7/16"	1764K47	00000
				25	25 1/8"	1 1/2"	1 1/2"	3/16"	No	16	7/16"	1764K92	00000
				26	26 1/8"	2"	2"	3/16"	No	16	7/16"	1764K48	00000
				27	27 1/8"	2"	2"	3/16"	No	16	7/16"	1764K93	00000
				28	28 1/8"	2"	2"	3/16"	No	16	7/16"	1764K49	00000
				29	29 1/8"	2"	2"	3/16"	No	16	7/16"	1764K94	00000
				30	30 1/8"	2"	2"	3/16"	No	16	7/16"	1764K63	00000


				32	32 1/8"	2"	2"	3/16"	No	16	7/16"	1764K96	00000
				34	34 1/8"	2"	2"	3/16"	No	16	7/16"	1764K98	00000
				36	36 1/8"	2"	2"	3/16"	No	16	7/16"	1764K101	00000
				38	38 1/8"	2"	2"	3/16"	No	24	7/16"	1764K103	00000
				40	40 1/8"	2"	2"	3/16"	No	24	7/16"	1764K105	000000
				42	42 1/8"	2"	2"	3/16"	No	24	7/16"	1764K107	000000
				44	44 1/8"	2"	2"	3/16"	No	24	7/16"	1764K109	000000
				46	46 1/8"	2"	2"	3/16"	No	24	7/16"	1764K112	000000
				48	48 1/8"	2"	2"	3/16"	No	24	7/16"	1764K114	000000
				52	52 1/8"	2"	2"	3/16"	No	24	7/16"	1764K118	000000




						Galvanized Steel

3						3 1/16"	1"	1"	1/8"	No	6	9/32"	1758K12	00000


3 1/2	3 17/32"					1"	1"	9/64"	No	6	9/32"	1758K125	00000
4	4 1/16"					1"	1"	1/8"	No	6	9/32"	1758K13	00000
4 1/2	4 17/32"	1"				1"	9/64"	No	6	9/32"	1758K135	00000
5	5 1/16"	1"	1"			1/8"	No	6	9/32"	1758K14	00000
5 1/2	5 17/32"	1"	1"			9/64"	No	6	9/32"	1758K145	00000
6	6 1/8"	1 1/4"	1 1/4"			1/8"	No	6	3/8"	1758K15	00000
7	7 1/8"	1 1/4"	1 1/4"			1/8"	No	6	3/8"	1758K16	00000
8	8 1/8"	1 1/4"	1 1/4"			1/8"	No	6	3/8"	1758K17	00000
9	9 1/8"	1 1/4"	1 1/4"			1/8"	No	6	3/8"	1758K18	00000
10	10 1/8"	1 1/4"	1 1/4"			1/8"	No	6	3/8"	1758K19	00000


11	11 1/8"	1 1/4"	1 1/4"			1/8"	No	6	3/8"	1758K36	00000
12	12 1/8"	1 1/2"	1 1/2"			1/8"	No	8	7/16"	1758K21	00000
13	13 1/8"	1 1/2"	1 1/2"			1/8"	No	8	7/16"	1758K22	00000
14	14 1/8"	1 1/2"	1 1/2"			1/8"	No	8	7/16"	1758K23	00000
15	15 1/8"	1 1/2"	1 1/2"			1/8"	No	8	7/16"	1758K24	00000
16	16 1/8"	1 1/2"	1 1/2"			3/16"	No	8	7/16"	1758K25	00000
17	17 3/16"	1 1/2"	1 1/2"			3/16"	No	8	7/16"	1758K42	00000
18	18 1/8"	1 1/2"	1 1/2"			3/16"	No	8	7/16"	1758K27	00000
20	20 1/8"	1 1/2"	1 1/2"			3/16"	No	12	7/16"	1758K29	00000
21	21 3/16"	1 1/2"	1 1/2"			3/16"	No	12	7/16"	1758K44	00000


22	22 1/8"	1 1/2"	1 1/2"			3/16"	No	12	7/16"	1758K33	00000
23	23 3/16"	1 1/2"	1 1/2"			3/16"	No	12	7/16"	1758K45	00000
24	24 1/8"	1 1/2"	1 1/2"			3/16"	No	12	7/16"	1758K35	00000
26	26 1/8"	2"	2"			3/16"	No	16	7/16"	1758K37	000000
28	28 1/8"	2"	2"			3/16"	No	16	7/16"	1758K39	000000
30	30 1/8"	2"	2"			3/16"	No	16	7/16"	1758K41	000000
34	34 3/16"	2"	2"			3/16"	No	16	7/16"	1758K53	000000
36	36 3/16"	2"	2"			3/16"	No	16	7/16"	1758K55	000000
38	38 3/16"	2"	2"			3/16"	No	24	7/16"	1758K57	000000
40	40 3/16"	2"	2"			3/16"	No	24	7/16"	1758K59	000000




		Corrosion-Resistant 304 Stainless Steel

		3	3 1/16"			7/8"	1"	1/8"	No	6	9/32"	1734K11	00000


		3 1/2	3 9/16"			1"	1"	9/64"	No	6	9/32"	1734K111	00000
		4	4 1/16"			1"	1"	1/8"	No	6	9/32"	1734K83	00000
		4 1/2	4 9/16"			1"	1"	9/64"	No	6	9/32"	1734K112	00000
		5	5 1/16"			1"	1"	1/8"	No	6	9/32"	1734K53	00000
		5 1/2	5 9/16"			1"	1"	9/64"	No	6	9/32"	1734K113	00000
		6	6 1/8"			1 1/4"	1 1/4"	1/8"	No	6	3/8"	1734K54	00000
		7	7 1/8"			1 1/4"	1 1/4"	1/8"	No	6	3/8"	1734K55	00000
		8	8 1/8"			1 1/4"	1 1/4"	1/8"	No	6	3/8"	1734K26	00000
		9	9 1/8"			1 1/4"	1 1/4"	1/8"	No	6	3/8"	1734K28	00000
		10	10 1/8"			1 1/4"	1 1/4"	1/8"	No	6	3/8"	1734K31	00000


		11	11 1/8"			1 1/4"	1 1/4"	1/8"	No	6	3/8"	1734K33	00000
		12	12 1/8"			1 1/2"	1 1/2"	1/8"	No	8	7/16"	1734K35	00000
		13	13 1/8"			1 1/2"	1 1/2"	1/8"	No	8	7/16"	1734K37	00000
		14	14 1/8"	1 1/2"		1 1/2"	1/8"	No	8	7/16"	1734K39	00000
		15	15 1/8"	1 1/2"	1 1/2"	1/8"	No	8	7/16"	1734K42	00000
		16	16 1/8"	1 1/2"	1 1/2"	3/16"	No	8	7/16"	1734K43	000000
		18	18 1/8"	1 1/2"	1 1/2"	3/16"	No	8	7/16"	1734K44	000000
		19	19 1/8"	1 1/2"	1 1/2"	3/16"	No	12	7/16"	1734K115	000000
		20	20 1/8"	1 1/2"	1 1/2"	3/16"	No	12	7/16"	1734K45	000000
		22	22 1/8"	1 1/2"	1 1/2"	3/16"	No	12	7/16"	1734K46	000000


		24	24 1/8"	1 1/2"	1 1/2"	3/16"	No	12	7/16"	1734K47	000000
		26	26 1/8"	2"	2"	3/16"	No	16	7/16"	1734K48	000000
		28	28 1/8"	2"	2"	3/16"	No	16	7/16"	1734K49	000000
		30	30 1/8"	2"	2"	3/16"	No	16	7/16"	1734K82	000000
		32	32 1/8"	2"	2"	3/16"	No	16	7/16"	1734K123	000000
		36	36 1/8"	2"	2"	3/16"	No	16	7/16"	1734K127	000000
		38	38 1/8"	2"	2"	3/16"	No	24	7/16"	1734K129	000000
		40	40 1/8"	2"	2"	3/16"	No	24	7/16"	1734K132	000000


		Without Mounting Holes







						Steel

						3	3 1/16"	1"	1"	1/8"	—	—	—	1764K81	0000


						4	4 1/16"	1"	1"	1/8"	—	—	—	1764K82	00000
						5	5 1/16"	1"	1"	1/8"	—	—	—	1764K83	00000
						6	6 1/8"	1 1/4"	1 1/4"	1/8"	—	—	—	1764K51	00000
						7	7 1/8"	1 1/4"	1 1/4"	1/8"	—	—	—	1764K52	00000
						8	8 1/8"	1 1/4"	1 1/4"	1/8"	—	—	—	1764K53	00000
						9	9 1/8"	1 1/4"	1 1/4"	1/8"	—	—	—	1764K54	00000
						10	10 1/8"	1 1/4"	1 1/4"	1/8"	—	—	—	1764K55	00000
						11	11 1/8"	1 1/4"	1 1/4"	1/8"	—	—	—	1764K56	00000
						12	12 1/8"	1 1/2"	1 1/2"	1/8"	—	—	—	1764K57	00000
						13	13 1/8"	1 1/2"	1 1/2"	1/8"	—	—	—	1764K58	00000


14	14 1/8"					1 1/2"	1 1/2"	1/8"	—	—	—	1764K59	00000
15	15 1/8"					1 1/2"	1 1/2"	1/8"	—	—	—	1764K61	00000
16	16 1/8"					1 1/2"	1 1/2"	3/16"	—	—	—	1764K62	00000
18	18 1/8"					1 1/2"	1 1/2"	3/16"	—	—	—	1764K64	00000
20	20 1/8"					1 1/2"	1 1/2"	3/16"	—	—	—	1764K66	00000
22	22 1/8"					1 1/2"	1 1/2"	3/16"	—	—	—	1764K68	00000
24	24 1/8"					1 1/2"	1 1/2"	3/16"	—	—	—	1764K71	00000
26	26 1/8"					2"	2"	3/16"	—	—	—	1764K73	00000
28	28 1/8"					2"	2"	3/16"	—	—	—	1764K75	00000
30	30 1/8"					2"	2"	3/16"	—	—	—	1764K76	00000




						Corrosion-Resistant 304 Stainless Steel

						4	4 1/16"	1"	1"	1/8"	—	—	—	1734K12	00000


						5	5 1/16"	1"	1"	1/8"	—	—	—	1734K13	00000
						6	6 1/8"	1 1/4"	1 1/4"	1/8"	—	—	—	1734K14	00000
						7	7 1/8"	1 1/4"	1 1/4"	1/8"	—	—	—	1734K15	00000
						8	8 1/8"	1 1/4"	1 1/4"	1/8"	—	—	—	1734K16	00000
						9	9 1/8"	1 1/4"	1 1/4"	1/8"	—	—	—	1734K17	00000
						10	10 1/8"	1 1/4"	1 1/4"	1/8"	—	—	—	1734K18	00000
						11	11 1/8"	1 1/4"	1 1/4"	1/8"	—	—	—	1734K19	00000
						12	12 1/8"	1 1/2"	1 1/2"	1/8"	—	—	—	1734K21	00000
						13	13 1/8"	1 1/2"	1 1/2"	1/8"	—	—	—	1734K22	00000
						14	14 1/8"	1 1/2"	1 1/2"	1/8"	—	—	—	1734K23	00000


						15	15 1/8"	1 1/2"	1 1/2"	1/8"	—	—	—	1734K24	00000
						16	16 1/8"	1 1/2"	1 1/2"	3/16"	—	—	—	1734K25	000000
						18	18 1/8"	1 1/2"	1 1/2"	3/16"	—	—	—	1734K27	000000
						20	20 1/8"	1 1/2"	1 1/2"	3/16"	—	—	—	1734K29	000000
						22	22 1/8"	1 1/2"	1 1/2"	3/16"	—	—	—	1734K32	000000
						24	24 1/8"	1 1/2"	1 1/2"	3/16"	—	—	—	1734K34	000000
						26	26 1/8"	2"	2"	3/16"	—	—	—	1734K36	000000
						28	28 1/8"	2"	2"	3/16"	—	—	—	1734K38	000000
						30	30 1/8"	2"	2"	3/16"	—	—	—	1734K41	000000

Quick-Disconnect Duct and Fittings

The fastest ductwork to disassemble for dust collection and other frequently cleaned systems. Join sections with quick-release clamps that open and close with a flip of the latch. Since you don’t need screws, welds, or tools, the installation time is half that of other duct types.

Straight Adapters

Duct-to-Duct

Flanged

Adapter

Bridge the gap between quick disconnect and other types of duct. These adapters mate with standard and spiral round duct, flanged duct fittings, or duct hose.

Duct-to-Duct Flanged Adapter—The flange joins quick-disconnect duct to fittings that have a flanged connection.

Galvanized Steel—Corrosion resistant and affordable, galvanized steel is the most commonly used ductwork material.

				Galvanized Steel		Corrosion-Resistant 304 Stainless Steel
	Duct Size	ID	Ga.		Each		Each
Duct-to-Duct Flanged Adapter



		3	3 1/16"	22	1761K384	000000	2538K527	0000000


		4	3 7/8"	22	1761K752	00000	2538K181	000000
		5	4 7/8"	22	1761K753	00000	2538K182	000000
		6	5 7/8"	22	1761K754	00000	2538K183	000000
		7	6 7/8"	22	1761K637	000000	2538K771	000000
		8	7 7/8"	22	1761K187	000000	2538K184	000000
		9	8 7/8"	22	1761K638	000000	2538K772	000000
		10	9 7/8"	22	1761K188	000000	2538K185	000000
		12	12"	22	1761K189	000000	2538K186	000000
		14	13 15/16"	20	1761K143	000000	2538K666	000000
		16	15 15/16"	20	1761K144	000000	2538K667	000000


		18	17 15/16"	20	1761K385	000000	2538K528	000000
		20	19 15/16"	20	1761K386	000000	2538K529	000000
		22	22"	20	1761K387	000000	———	0
		24	23 15/16"	20	1761K388	000000	———	0

Snap-On Drop-Ceiling Diffuser Collars

Connect drop-ceiling diffusers to duct. Use the included push-in fasteners to attach collar to diffuser.

For Duct Size	OD	Gender	Material		Each
6	5 15/16"	Male	Galvanized Steel	18525K44	000000
8	7 15/16"	Male	Galvanized Steel	18525K45	00000
10	9 15/16"	Male	Galvanized Steel	18525K46	00000
12	11 15/16"	Male	Galvanized Steel	18525K47	00000