2-56 Taps | McMaster-Carr

Cobalt Steel—These taps resist higher temperatures and and last twice as long as high-speed steel taps. They thread hard materials such as iron and hardened steel without damaging their cutting edges.

Carbide—The hardest and most wear-resistant taps. They last 10 times longer than high-speed steel for the best performance on hard and abrasive materials like nickel and fiberglass. Carbide can be brittle, however, so these taps require a rigid machine tool holder to prevent breakage and should not be used for hand tapping.

Carbon Steel—The economical choice for occasional hand tapping. These work on most metals and plastic but will dull more quickly than other taps.

Uncoated—The economical choice, these won't last as long as coated taps.

Titanium Nitride (TiN) Coated—Run at higher speeds and last twice as long as uncoated taps.

Titanium Carbon Nitride (TiCN) Coated—Resist heat, chipping, and wear for three times the life of uncoated taps.

Titanium Aluminum Nitride (TiAlN) Coated—No taps last longer. These are the best for high-speed, high-temperature drilling of tough materials such as iron.

Taper Chamfer—Good for both starting holes and threading through holes. These taps have the longest taper to gradually engage with the material, reducing the force needed to turn them. They can't reach the bottom of blind holes, however, so you will likely need to finish with a bottoming-chamfer tap.

Plug Chamfer—Our go-to chamfer type, these thread both through holes and blind holes. The tapered section is shorter than a taper chamfer and longer than bottoming chamfer. As a result, they're easier to turn than bottoming taps but require more force than taper taps.

Bottoming Chamfer—Cut all the way to the bottom of blind holes with taps that have the shortest taper. Since these require the most force to turn, they’re often used to finish holes started by taper- or plug-chamfer taps.

Number of Flutes—Taps with fewer flutes have more space to capture chips, so you won’t have to clear them as often. However, they can be more difficult to keep straight in the hole.

Taps Sold as Sets—Include one tap of each chamfer type.

	Taps														Taps Sold as Sets
						Drill Bit			Taper Chamfer		Plug Chamfer		Bottoming Chamfer
	Thread Size	Thread Lg.	Overall Lg.	Thread Type	No. of Flutes	Size	Decimal Size Equiv.	Shank Type		Each		Each		Each	No. of Taps		Each
High-Speed Steel







				Uncoated

				2-56	7/16"	1 3/4"	UNC	2	51 Ga.	0.067"	Square	———	0	26955A21	000000	26955A61	000000	—	———	0


				2-56	7/16"	1 3/4"	UNC	3	51 Ga.	0.067"	Square	2522A663	000000	2522A713	00000	2522A733	00000	3	2522A863	000000




						Titanium Nitride (TiN) Coated

						2-56	7/16"	1 3/4"	UNC	2	51 Ga.	0.067"	Square	2636A115	00000	26955A11	00000	26955A68	00000	—	———	0




								Titanium Carbon Nitride (TiCN) Coated

								2-56	7/16"	1 3/4"	UNC	3	51 Ga.	0.067"	Square	26545A112	00000	26545A17	00000	26545A142	00000	3	26545A172	00000


								Cobalt Steel







												Uncoated

												2-56	7/16"	1 13/16"	UNC	2	51 Ga.	0.067"	Square	———	0	2662A53	00000	———	0	—	———	0




														Titanium Nitride (TiN) Coated

														2-56	7/16"	1 13/16"	UNC	2	51 Ga.	0.067"	Square	———	0	2662A71	00000	———	0	—	———	0


														Carbide







																		Titanium Aluminum Nitride (TiAlN) Coated

																		2-56	7/16"	1 3/4"	UNC	2	51 Ga.	0.067"	Square	———	0	7822N52	000000	7822N58	000000	—	———	0


																		Carbon Steel







			Uncoated

			2-56																7/16"	1 3/4"	UNC	3	51 Ga.	0.067"	Square	25995A123	0000	25995A143	0000	25995A163	0000	—	———	0

Chip-Clearing Tap Sets

A range of sizes that remove chips so they don’t ruin the threads or jam the tap. The spiral-point flutes force chips through the hole to prevent buildup and create threads faster than standard taps. Also known as gun taps.

High-Speed Steel

Image of Product. Front orientation. Taps. Chip-Clearing Tap Sets.

The most versatile taps resist heat and wear to stay sharp. They’re good for most metals and plastic.

Gold Oxide—The finish increases wear resistance and reduces friction to improve chip flow, so these taps can last 50% longer than uncoated taps.

							Plug Chamfer
	No. of Pieces	Thread Size	Thread Type	Flute Type	Container Type	Shank Type		Each
Gold Oxide



		19	0-80, 1-64, 1-72, 2-56, 2-64, 3-48, 3-56, 4-40, 4-48, 5-40, 5-44, 6-32, 6-40, 8-32, 8-36, 10-24, 10-32, 12-24, 12-28	UNF, UNC	Spiral Point	Metal Case	Square	27275A22	0000000

Tap Sets

These sets include a variety of taps for threading holes so screws, bolts, and rods fit snugly.

High-Speed Steel—Single Thread Size Sets

Taper, Plug, and Bottoming

Chamfer Set

The most versatile taps resist heat and wear to stay sharp. They’re good for most metals and plastic. These sets include one of each chamfer type: Taper for starting holes and threading through holes; plug for through holes and blind holes; and bottoming for cutting the closest to the bottom of any hole.

Uncoated—The economical choice, these won't last as long as coated taps.

Titanium Nitride (TiN) Coated—Run at higher speeds and last twice as long as uncoated taps.

Titanium Carbon Nitride (TiCN) Coated—Resist heat, chipping, and wear for three times the life of uncoated taps.

							Taper Chamfer, Plug Chamfer, Bottoming Chamfer
	No. of Pieces	Thread Size	Thread Type	Container Type	No. of Flutes	Shank Type		Each
Uncoated



		3	2-56	UNC	Plastic Case	3	Square	2522A863	000000


		Titanium Nitride (TiN) Coated



				3	2-56	UNC	Plastic Case	2	Square	2636A118	00000


				Titanium Carbon Nitride (TiCN) Coated



						3	2-56	UNC	Plastic Case	3	Square	26545A172	00000

High-Speed Steel—Multiple Thread Size Sets

Plug Chamfer Set

The most versatile taps resist heat and wear to stay sharp. They’re good for most metals and plastic. These sets include multiple sizes of plug chamfer taps for through holes and blind holes.

Uncoated—The economical choice, these won't last as long as coated taps.

						Plug Chamfer
	No. of Pieces	Thread Size	Thread Type	Container Type	Shank Type		Each
Uncoated



		19	1 each of sizes 0-80, 1-64, 1-72, 2-56, 2-64, 3-48, 3-56, 4-40, 4-48; 5-40, 5-44, 6-32, 6-40, 8-32, 8-36, 10-24, 10-32, 12-24, and 12-28	UNF, UNC	Metal Case	Square	27045A21	0000000

Carbon Steel—Single Thread Size Sets

Taper, Plug, and Bottoming

Chamfer Set

The economical choice for occasional hand tapping. These work on most metals and plastic but will dull more quickly than other taps. Sets include one each chamfer type: Taper for starting holes and through holes; plug for through holes and blind holes; and bottoming for cutting the closest to the bottom of any hole.

							Taper Chamfer, Plug Chamfer, Bottoming Chamfer
	No. of Pieces	Thread Size	Thread Type	Container Type	No. of Flutes	Shank Type		Each
Uncoated



		3	2-56	UNC	Plastic Case	3	Square	25995A333	000000

Chip-Clearing Taps for Steel and Stainless Steel

Spiral-Point Flute for Through Holes

Image of ProductInUse. Front orientation. Contains Annotated. Taps. Chip-Clearing Taps for Steel and Stainless Steel, Spiral Flute for Blind Holes.

Spiral Flute for Blind Holes

Made of a high-vanadium alloy, these taps are harder and more wear-resistant than other high-speed steel taps. The flute design prevents buildup to protect the quality of the threads and avoid damage to the tap. Since you don’t need to reverse these taps to extract chips, they also create threads faster.

High-Speed Steel—The most versatile taps resist heat and wear to stay sharp. They’re good for most metals and plastic.

Black Oxide—The dark finish increases wear resistance and reduces friction to improve chip flow, so these taps can last 50% longer than uncoated taps.

Spiral-Point Flute for Through Holes—Push chips ahead of the tap and out of through holes. Also known as gun taps.

Spiral Flute for Blind Holes—Pull chips back toward the tap so they won't build up in blind holes. When tapping brittle material like iron that creates fine or powdery debris, choose a straight-flute tap.

Plug Chamfer—Our go-to chamfer type. With a longer taper than a bottoming chamfer, they are easier to turn but won't thread as close the bottom of a hole.

Bottoming Chamfer—These taps have the shortest taper to thread close to the bottom of blind holes. They require the most force to turn, so they’re often used to finish holes started by plug-chamfer taps.

					Drill Bit			Spiral-Point Flute for Through Holes				Spiral Flute for Blind Holes
	Thread Size	Thread Lg.	Overall Lg.	Thread Type	Size	Decimal Size Equiv.	Shank Type	Chamfer Type	No. of Flutes		Each	Chamfer Type	No. of Flutes		Each
High-Speed Steel







				Black Oxide

				2-56	3/8"	1 3/4"	UNC	51 Ga.	0.067"	Square	Plug	2	2684A61	000000	—	—	———	0


				2-56	13/32"	1 3/4"	UNC	51 Ga.	0.067"	Square	—	—	———	0	Bottoming	2	27055A11	000000

Chip-Clearing Taps for Aluminum, Brass, and Bronze

Spiral Flute for Through Holes

Spiral Flute for Blind Holes

Long, gummy strands from soft metals won’t get stuck on the tap or in the hole. With two layers of slippery coating over spiral flutes, these taps prevent chip buildup that can harm the threads and the tap.

Cobalt Steel—Tough and wear resistant, cobalt taps last twice as long as high-speed steel. They also can run at higher temperatures without damage to their cutting edges.

Titanium Nitride (TiN) Coated—Run at higher speeds and last twice as long as uncoated taps.

Spiral Flute for Through Holes—Left-hand flutes push chips ahead of the tap and out of through holes.

Spiral Flute for Blind Holes—Pull chips back toward the tap so they won't build up in blind holes.

Plug Chamfer—Our go-to chamfer type. With a longer taper than a bottoming chamfer, they are easier to turn but won't thread as close the bottom of a hole.

					Drill Bit			Spiral Flute for Through Holes				Spiral Flute for Blind Holes
	Thread Size	Thread Lg.	Overall Lg.	Thread Type	Size	Decimal Size Equiv.	Shank Type	Chamfer Type	No. of Flutes		Each	Chamfer Type	No. of Flutes		Each
Cobalt Steel







				Titanium Nitride (TiN) Coated/Chromium Carbide (CrC) Coated

				2-56	5/16"	1 49/64"	UNC	51 Ga.	0.067"	Square	Plug	2	2687A41	000000	Bottoming	3	2687A74	000000

Chip-Clearing Taps

Spiral-Point Flute for Through Holes

Remove long, stringy chips to produce cleaner threads than standard taps. The flute design prevents buildup to protect the quality of the threads and avoid damage to the tap. Since you don’t need to reverse these taps to extract chips, they also create threads faster.

High-Speed Steel—The most versatile taps resist heat and wear to stay sharp. They’re good for most metals and plastic.

Uncoated—The economical choice, these won't last as long as coated taps.

Titanium Nitride (TiN) Coated—Run at higher speeds and last twice as long as uncoated taps.

Titanium Carbon Nitride (TiCN) Coated—Resist heat, chipping, and wear for three times the life of uncoated taps.

Spiral-Point Flute for Through Holes—Push chips ahead of the tap and out of through holes. Also known as gun taps.

Plug Chamfer—Our go-to chamfer type. With a longer taper than a bottoming chamfer, they are easier to turn but won't thread as close the bottom of a hole.

					Drill Bit			Spiral-Point Flute for Through Holes
	Thread Size	Thread Lg.	Overall Lg.	Thread Type	Size	Decimal Size Equiv.	Shank Type	Chamfer Type	No. of Flutes		Each
High-Speed Steel







				Uncoated

				2-56	7/16"	1 3/4"	UNC	51 Ga.	0.067"	Square	Plug	2	2523A442	000000




						Titanium Nitride (TiN) Coated

						2-56	7/16"	1 3/4"	UNC	51 Ga.	0.067"	Square	Plug	2	2762A33	00000




								Titanium Carbon Nitride (TiCN) Coated

								2-56	7/16"	1 3/4"	UNC	51 Ga.	0.067"	Square	Plug	2	2568A32	00000

Long-Reach Chip-Clearing Taps

Push out chips while threading holes that are hard to reach or obstructed. These taps are double the length of standard taps to reach inside machines or through assemblies such as pulleys and belts. The flute design prevents buildup to protect the quality of the threads and avoid damage to the tap. Since you don’t need to reverse these taps to extract chips, they also create threads faster.

Black Oxide—The dark finish increases wear resistance and reduces friction to improve chip flow, so these taps can last 50% longer than uncoated taps.

Spiral-Point Flute for Through Holes—Push chips ahead of the tap and out of through holes. Also known as gun taps.

Plug Chamfer—Our go-to chamfer type. With a longer taper than a bottoming chamfer, they are easier to turn but won't thread as close the bottom of a hole.

					Drill Bit		Shank		Spiral-Point Flute for Through Holes
	Thread Size	Thread Lg.	Overall Lg.	Thread Type	Size	Decimal Size Equiv.	Type	Dia.	Chamfer Type	No. of Flutes		Each
Cobalt Steel







				Black Oxide

				2-56	7/16"	6"	UNC	51 Ga.	0.067"	Square	0.141"	Plug	2	2589A17	000000

Chip-Clearing Taps for Titanium

Spiral Flute for Blind Holes

Sharp, angled flutes cut through tough titanium alloys while reducing heat and preventing clogs. These taps draw out chips gradually to create clean threads and protect the tap from jamming or breaking.

Cobalt Steel—Tough and wear resistant, cobalt taps last twice as long as high-speed steel. They also can run at higher temperatures without damage to their cutting edges.

Black Oxide—The dark finish increases wear resistance and reduces friction to improve chip flow, so these taps can last 50% longer than uncoated taps.

Spiral Flute for Blind Holes—Pull chips back toward the tap so they won't build up in blind holes.

Plug Chamfer—Our go-to chamfer type. With a longer taper than a bottoming chamfer, they are easier to turn but won't thread as close the bottom of a hole.

					Drill Bit			Spiral Flute for Blind Holes
	Thread Size	Thread Lg.	Overall Lg.	Thread Type	Size	Decimal Size Equiv.	Shank Type	Chamfer Type	No. of Flutes		Each
Cobalt Steel







				Black Oxide

				2-56	1/4"	1 3/4"	UNC	51 Ga.	0.067"	Square	Plug	2	2401A24	000000

Helical Insert Taps

Match the size of helical inserts so they fit tightly when installed in the hole.

High-Speed Steel—These taps resist heat and wear to stay sharp.

Plug Chamfer—Our go-to chamfer type. With a longer taper than a bottoming chamfer, they are easier to turn but won't thread as close the bottom of a hole.

						Drill Bit			Plug Chamfer		Bottoming Chamfer
	For Insert Size	Thread Lg.	Overall Lg.	For Insert Thread Type	No. of Flutes	Size	Decimal Size Equiv.	Shank Type		Each		Each
High-Speed Steel







				Uncoated

				2-56	9/16"	1 7/8"	UNC	3	41 Ga.	0.096"	Square	91709A098	000000	91709A401	000000

Chip-Clearing Taps for Nickel

Spiral Flute for Through Holes

Spiral Flute for Blind Holes

Avoid heat buildup that can deform material and prematurely wear taps when threading nickel alloys. The body on these taps narrows closer to the flutes for better coolant flow and less contact with the workpiece. Spiral flutes prevent stuck chips that can slow you down and decrease the quality of the threads.

Cobalt Steel—Tough and wear resistant, cobalt taps last twice as long as high-speed steel. They also can run at higher temperatures without damage to their cutting edges.

Black Oxide—The dark finish increases wear resistance and reduces friction to improve chip flow, so these taps can last 50% longer than uncoated taps.

Spiral Flute for Through Holes—Left-hand flutes push chips ahead of the tap and out of through holes.

Spiral Flute for Blind Holes—Pull chips back toward the tap so they won't build up in blind holes.

Plug Chamfer—Our go-to chamfer type. With a longer taper than a bottoming chamfer, they are easier to turn but won't thread as close the bottom of a hole.

						Drill Bit			Spiral Flute for Through Holes			Spiral Flute for Blind Holes
	Thread Size	Thread Lg.	Overall Lg.	Thread Type	Chamfer Type	Size	Decimal Size Equiv.	Shank Type	No. of Flutes		Each	No. of Flutes		Each
Cobalt Steel







				Black Oxide

				2-56	7/16"	1 3/4"	UNC	Plug	51 Ga.	0.067"	Square	2	25595A14	000000	3	25595A18	000000

Helical Threaded Insert Assortments with Installation Tools

Repair damaged threads or create new ones. These convenient assortments include helical inserts, an installation tool for each thread size, a drill bit, and a tap. The inserts are also known as Heli-Coil inserts.

Pronged—The prong attaches to an installation tool for precise control as you drive inserts in. Remove the prong with a punch or break-off tool before inserting a screw.

18-8 Stainless Steel—The choice for wet and outdoor environments, these inserts resist rust and mild chemicals.

	Drill Bit Size	For Max. Hole Dia.		Each
Pronged







	18-8 Stainless Steel

	288	1-64 Thread × 0.11" Installed Lg. (24 Inserts and 24 Screw-Locking Inserts) 2-56 Thread × 0.129" Installed Lg. (24 Inserts and 24 Screw-Locking Inserts) 3-48 Thread × 0.148" Installed Lg. (24 Inserts and 24 Screw-Locking Inserts) 4-40 Thread × 0.168" Installed Lg. (24 Inserts and 24 Screw-Locking Inserts) 6-32 Thread × 0.207" Installed Lg. (24 Inserts and 24 Screw-Locking Inserts) 8-32 Thread × 0.246" Installed Lg. (24 Inserts and 24 Screw-Locking Inserts) Drill Bits Installation Tools Through-Hole Taps	Coarse	5/64" 3/32" 36 Ga. 31 Ga. 26 Ga. 17 Ga.	0.078" 0.094" 0.107" 0.120" 0.147" 0.173"	90285A134	0000000

Helical Threaded Inserts with Installation Tools

Drill Bit, Installation Tool

and Through-Hole Tap

Quickly restore stripped threads—these inserts come with through-hole taps and installation tools. The tough coils on these inserts expand once installed to anchor in a tapped hole.

Pronged—The prong attaches to an installation tool for precise control as you drive inserts in. Remove the prong with a punch or break-off tool before inserting a screw.

18-8 Stainless Steel—The choice for wet and outdoor environments, these inserts resist rust and mild chemicals.

	For Max. Hole Dia.	No. of Inserts Included	Includes		Each
Pronged







	18-8 Stainless Steel

	2-56	0.086"	3/32"	0.094"	10	Drill Bit Installation Tool Through-Hole Tap	98356A111	0000000


	2-56	0.129"	3/32"	0.094"	10	Drill Bit Installation Tool Through-Hole Tap	91732A892	000000
	2-56	0.172"	3/32"	0.094"	10	Drill Bit Installation Tool Through-Hole Tap	98356A112	000000
	2-56	0.215"	3/32"	0.094"	10	Drill Bit Installation Tool Through-Hole Tap	98356A113	000000

Thread-Forming Locknuts

Form threads into these nuts for a tight fit that won't loosen under vibration. They are partially threaded, so when you fasten them onto metal screws, the tightening action will cut the rest of the threads. Nuts are not reusable.

Plastic

Nylon 6/6—Slippery and abrasion resistant, these nuts thread on smoothly and stand up to daily wear and tear. Nylon will swell and weaken when exposed to moisture, so it's best for dry environments.

	Wd.	Ht.	Pkg. Qty.		Pkg.
White Nylon 6/6



	2-56	3/16"	1/16"	100	94909A002	000000