1 1/2"-6 Taps | McMaster-Carr

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

				1 1/2"-6	3"	6 3/8"	UNC	4	1 11/32"	1.3438"	Square	2521A855	0000000	2521A856	0000000	2521A857	0000000	3	2521A858	0000000


				Carbon Steel







								Uncoated

								1 1/2"-6	3"	6 3/8"	UNC	4	1 11/32"	1.3438"	Square	26035A136	000000	26035A171	000000	26035A194	000000	—	———	0

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.

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



		3	1 1/2"-6	UNC	Plastic Case	4	Square	2521A858	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	1 1/2"-6	UNC	Plastic Case	4	Square	26035A366	0000000

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.

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			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







				Black Oxide

				1 1/2"-6	2"	6.38"	UNC	1 11/32"	1.343"	Square	Plug	4	2523A85	0000000

Left-Hand Thread Taps

Create left-hand threads that prevent counter-clockwise rotating parts, such as flywheels and propellers, from loosening and spinning off. These taps have straight flutes that are good for most jobs.

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.

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

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







				Uncoated

				1 1/2"-6	3"	6 3/8"	UNC	4	1 11/32"	1.3438"	Square	2584A08	0000000	2584A28	0000000	3	2584A569	0000000

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

				1 1/2"-6	3 3/16"	7"	UNC	6	1 35/64"	1.5469"	Square	91709A119	0000000	91709A518	0000000

Left-Hand Thread Tap Sets

Three chamfer types in one set create a snug fit with left-hand fasteners that secure counter-clockwise rotating parts. Left-hand threads keep components such as flywheels and propellers from loosening and spinning off. These taps have straight flutes that are good for most jobs.

High-Speed Steel—Single Thread Size Sets

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

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



		3	1 1/2"-6	UNC	4	Square	2584A569	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

	1 1/2"-6	2.250"	1 17/32"	1.531"	4	Drill Bit Installation Tool Through-Hole Tap	91732A325	0000000