Pipe Thread Gauges | McMaster-Carr

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	For Thread Type For Thread Type

	For Use With For Use With

	For Thread Location For Thread Location

External

Internal

	For System of Measurement For System of Measurement

Inch

Metric

	Material Material

	For Pipe Size For Pipe Size

	Container Container

Folding Case

Pouch

	System of Measurement System of Measurement

Inch

Metric

	For Gender For Gender

Female

Male

	Pipe Size Pipe Size

	Thread Type Thread Type

NPT

	For Threads per Inch For Threads per Inch

3
3 1/2
4
4 1/2
5
5 1/2
6
7
7 1/2
8
9
10
11
11 1/2
12
13
14
16
18
20
24
27
28
32
36
40
44
48

	For Thread Pitch For Thread Pitch

	DFARS (Defense Acquisition Regulations Supplement) DFARS (Defense Acquisition Regulations Supplement)

DFARS Specialty Metals
COTS-Exempt

	RoHS (Restriction of Hazardous Substances) RoHS (Restriction of Hazardous Substances)

RoHS Compliant

	REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) REACH (Registration, Evaluation, Authorization and Restriction of Chemicals)

REACH Compliant

	Color Color

	Blue
	Silver

	Width Width

3 3/4"

8 11/16"

10 1/2"

	Height Height

	Thickness Thickness

1/32"

7/64"

1/4"

	For Pipe Fitting Size For Pipe Fitting Size

	For Pipe Material For Pipe Material

Brass

PVC

Steel

	Class Class

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54 Products

Thread Identifier Sets

Set includes calipers and gauges to identify external and internal threads.

			Container
For Use With	For Thread Type	For Thread Location	Type	Material	Includes		Each
Inch, Metric
Steel
Screws, Bolts, Threaded Rods, Nuts, Pipe	NPT, UNC, UNF, BSPT, BSPP, Metric	External/Internal	Folding Case	Plastic	Caliper, Instruction Book, Two Steel Angle Gauges, Two Steel Gauges	000000	000000

Pipe Thread and Thread Pitch Identifiers

In addition to checking NPT and BSPT pipe sizes, use the two included gauges for measuring thread pitch.

For Thread Type	For Pipe Size	For Gender	Wd.	Ht.	Thick.	Thread Size Identifier Material	Thread Pitch Identifier Material	Color		Each
BSPT, NPT	1/8, 1/4, 3/8, 1/2, 3/4, 1, 1 1/4, 1 1/2, 2	Female, Male	9"	4 1/4"	1/4"	Plastic	Steel	Blue	000000	00000

Pipe Thread Identifiers

Check external NPT thread size and taper.

Aluminum
For Thread Type	For Thread Location	For Pipe Size	Wd.	Ht.	Thick.	Color		Each
NPT	External	1/16, 1/8, 1/4, 3/8, 1/2	2"	3"	1/4"	Blue	000000	000000

Pipe, Tubing, and Hose Size Identifiers

For Pipe, Tubing, And Hose

For Pipe, Pipe Fittings, And Hose

Determine pipe size and inner and outer diameter.

Pipe, pipe fittings, and hose identifier is stainless steel for corrosion resistance.

Plastic
For Use With	For Pipe Size	For Pipe Fitting Size	For Tube OD	For Hose ID	Includes	Wd.	Ht.	Thick.	Color		Each
Pipe, Tubing, Hose	1/8, 1/4, 3/8, 1/2, 3/4	__	1/8", 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", 5/8", 3/4", 1"	1/4", 3/8", 1/2", 3/4", 1"	Compression Fitting Chart	9"	3 3/4"	7/64"	Blue	0000000	00000
Stainless Steel
Pipe, Pipe Fittings, Hose	1/8, 1/4, 3/8, 1/2, 3/4, 1, 1 1/4, 1 1/2, 2	1/8, 1/4, 3/8, 1/2, 3/4, 1, 1 1/4, 1 1/2, 2	__	1/8", 1/4", 5/16", 3/8", 5/8", 3/4", 7/8", 1", 1 1/8", 1 1/4"	__	3 3/4"	4 1/2"	1/32"	Silver	00000000	00000

All-in-One Identifiers

Find tube, pipe, fastener, wire, and drill bit sizes with one tool.

Plastic
For Use With (Number of Sizes)	Wd.	Ht.	Material		Each
Tube (9), Tube Fittings (6), Pipe (9), Pipe Fittings (6), Screws and Bolts (20), Threaded Rods, Nuts (14), Nails (11), Wire (30), Drill Bits (21)	8 11/16"	4 1/4"	Plastic	00000000	00000
Tube (11), Tube Fittings (10), Pipe (16), Pipe Fittings (10), Screws and Bolts (20), Threaded Rods, Nuts (20), Nails (16), Wire (51), Drill Bits (50)	10 1/2"	3 1/2"	Plastic	00000000	0000

Threaded Plug Gauges for NPT Pipe Threads

A notch on the handle indicates when the internal NPT threads you’re checking are in tolerance. Gauges have a taperlock handle for quickly replacing worn gauges.

For technical drawings and 3-D models, click on a part number.

Class X
Pipe Size	Pitch Diameter Tolerance	Hardness	Material		Each
1/16	-0.0002" to 0.0002"	Rockwell C60	Tool Steel	0000000	0000000
1/8	-0.0002" to 0.0002"	Rockwell C60	Tool Steel	00000000	000000
1/4	-0.0002" to 0.0002"	Rockwell C60	Tool Steel	00000000	000000
3/8	-0.0002" to 0.0002"	Rockwell C60	Tool Steel	00000000	000000
1/2	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
3/4	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
1	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
1 1/4	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
1 1/2	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
2	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000

Threaded Plug Gauges for NPT Pipe Threads with Calibration Certificate

Ensure the accuracy of internal NPT pipe thread measurements—these gauges come with a certificate of calibration traceable to NIST that states they’ve passed a test for accuracy. A notch on the handle indicates when the threads you’re checking are in tolerance. Gauges have a taperlock handle for quickly replacing worn gauges.

For technical drawings and 3-D models, click on a part number.

Class X
Pipe Size	Pitch Diameter Tolerance	Hardness	Material		Each
1/16	-0.0002" to 0.0002"	Rockwell C60	Tool Steel	00000000	0000000
1/8	-0.0002" to 0.0002"	Rockwell C60	Tool Steel	00000000	000000
1/4	-0.0002" to 0.0002"	Rockwell C60	Tool Steel	00000000	000000
3/8	-0.0002" to 0.0002"	Rockwell C60	Tool Steel	00000000	000000
1/2	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
3/4	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
1	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
1 1/4	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
1 1/2	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
2	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
2 1/2	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
3	-0.0005" to 0.0005"	Rockwell C60	Tool Steel	00000000	000000
4	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000

Threaded Ring Gauges for NPT Pipe Threads with Calibration Certificate

To ensure accuracy of external NPT pipe thread measurements, these gauges include a certificate of calibration traceable to NIST that states they’ve passed a test for accuracy.

For technical drawings and 3-D models, click on a part number.

Class X
Pipe Size	Pitch Diameter Tolerance	Hardness	Material		Each
1/16	-0.0002" to 0.0002"	Rockwell C60	Tool Steel	00000000	0000000
1/8	-0.0002" to 0.0002"	Rockwell C60	Tool Steel	00000000	000000
1/4	-0.0002" to 0.0002"	Rockwell C60	Tool Steel	00000000	000000
3/8	-0.0002" to 0.0002"	Rockwell C60	Tool Steel	00000000	000000
1/2	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
3/4	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
1	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
1 1/4	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
1 1/2	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
2	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
2 1/2	-0.0005" to 0.0005"	Rockwell C60	Tool Steel	00000000	000000
3	-0.0005" to 0.0005"	Rockwell C60	Tool Steel	00000000	000000
4	-0.0005" to 0.0005"	Rockwell C60	Tool Steel	00000000	00000000

Threaded Ring Gauges for NPT Pipe Threads

Check the external threads of NPT pipe to ensure they fall within tolerance.

For technical drawings and 3-D models, click on a part number.

Class X
Pipe Size	Pitch Diameter Tolerance	Hardness	Material		Each
1/16	-0.0002" to 0.0002"	Rockwell C60	Tool Steel	0000000	0000000
1/8	-0.0002" to 0.0002"	Rockwell C60	Tool Steel	00000000	000000
1/4	-0.0002" to 0.0002"	Rockwell C60	Tool Steel	00000000	000000
3/8	-0.0002" to 0.0002"	Rockwell C60	Tool Steel	00000000	000000
1/2	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
3/4	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
1	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
1 1/4	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
1 1/2	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000
2	-0.0003" to 0.0003"	Rockwell C60	Tool Steel	00000000	000000

Threads per Inch and Thread Pitch Size Checkers

Inspect fasteners and verify threads with this checker. It includes three wires for each of the pitch diameters. Select the wire that best fits the threads; then calculate the pitch diameter with the equations provided.

							Wire
For Use With	For Thread Type	For Thread Location	For Threads per Inch	For Thread Pitch	For Acme Threads per Inch	No. of Wires	Lg.	Material	Container	Container Material		Each
Inch; Metric
Screws, Bolts, Threaded Rods, Pipe	NPT, UNC, UNF, Metric, Acme	External	3, 3 1/2, 4, 4 1/2, 5, 5 1/2, 6, 7, 7 1/2, 8, 9, 10, 11, 11 1/2, 12, 13, 14, 16, 18, 20, 24, 27, 28, 32, 36, 40, 44, 48	0.5 mm, 0.6 mm, 0.7 mm, 0.75 mm, 0.8 mm, 1 mm, 1.25 mm, 1.5 mm, 1.75 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm	3, 4, 5, 6, 8, 10, 12, 14, 16	48	2 3/4"	Stainless Steel	Pouch	Vinyl	000000	000000