Thread Finders | McMaster-Carr

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

REACH Compliant

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

RoHS Compliant

	For Screw Size For Screw Size

	For Thread Fit For Thread Fit

	Thread Type Thread Type

	For Pipe Size For Pipe Size

	For Threads per Inch For Threads per Inch

1
1 1/3
1 1/2
1 3/4
2
2 1/2
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
15
16
18
19
20
22
24
25
26
27
28
29
30
32
34
36
38
40
42
44
46
48
50
52
54
56
58
60
62
64
66
68
70
72
74
76
78
80
82
84

	Gauge Type Gauge Type

No-Go

Master

	Container Container

Folding Case

Pouch

	Number of Identifiers Number of Identifiers

	Manufacturer Manufacturer

Mitutoyo

Starrett

	Class Class

Forward

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615 Products

Size Identifying

Wall-Mount Thread-It Screw,
Bolt, and Nut Size Identifiers

Mount to a wall for easy access, and thread your fastener into holes or onto plugs for quick and accurate size identification.

Thread-It Screw, Bolt, and Nut Size Identifiers

Thread your fastener into holes or onto plugs for quick and accurate size identification.

Threads per Inch and Thread Pitch Identifiers

Determine threads per inch and thread pitch on a variety of external and internal threads.

Screw Size Identifiers

Find thread size, screw size, diameter, and drill bit size with one tool.

Thread Identifier Sets

Set includes calipers and gauges to identify external and internal threads

Screw, Bolt, and Nut Size Identifiers

Use on external and internal fastener threads.

Acme Thread Identifiers

Identify Acme threads and use as a guide while grinding and cutting Acme threads to a 29° included angle.

Threads per Inch and Center Identifiers

Identify threads per inch on external threads and find the center of your workpiece to line up thread cutting tools.

Pipe Thread and Thread Pitch Identifiers

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

Pipe Thread Identifiers

Check external NPT thread size and taper.

Pipe, Tubing, and Hose Size Identifiers

Determine pipe size and inner and outer diameter.

All-in-One Identifiers

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

Drill Bit Size Identifiers

Measure drill bit sizes with these identifiers.

Size Checking

Threads per Inch and Thread Pitch Size Checkers

Inspect fasteners and verify threads with this checker.

Threaded Plug Gauges for NPT Pipe
Threads with Calibration Certificate

Ensure the accuracy of NPT thread measurements—these gauges come with a certificate of calibration traceable to NIST that states they’ve passed a test for accuracy.

Threaded Plug Gauges

These have a go gauge on one end and a no-go gauge on the other end.

Threaded Plug Gauges for NPT Pipe Threads

A notch on the handle indicates when the internal NPT threads you’re checking are in tolerance.

Threaded Plug Gauges with Calibration Certificate

These gauges come with a certificate of calibration traceable to NIST that states they’ve passed a test for accuracy.

Master Ring Gauges

Set inside micrometers, dial bore gauges, and other precision tools.

Threaded Ring Gauges with Calibration Certificate

A certificate of calibration traceable to NIST states that these gauges have passed a test for accuracy.

Threaded Ring Gauges

Check a part’s external threads to ensure they fall within tolerance.

Threaded Ring Gauges for NPT Pipe
Threads with Calibration Certificate

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

Threaded Ring Gauges for NPT Pipe Threads

Measure NPT pipe threads.

Ring Gauges for Outside Diameters

Use these gauges to check the outside diameter of shafts, rods, and other cylindrical objects to determine whether they’re in tolerance.

Thread Gauges for Lug Nuts

Identify the most common bolt thread sizes.

Gear Tooth Pitch Identifiers

When replacing a gear, use these gauges to identify pressure angle, pitch, and module.

Size Identifying

Wall-Mount Thread-It Screw,Bolt, and Nut Size Identifiers

Thread-It Screw, Bolt, and Nut Size Identifiers

Threads per Inch and Thread Pitch Identifiers

Screw Size Identifiers

Thread Identifier Sets

Screw, Bolt, and Nut Size Identifiers

Acme Thread Identifiers

Threads per Inch and Center Identifiers

Pipe Thread and Thread Pitch Identifiers

Pipe Thread Identifiers

Pipe, Tubing, and Hose Size Identifiers

All-in-One Identifiers

Drill Bit Size Identifiers

Size Checking

Threads per Inch and Thread Pitch Size Checkers

Threaded Plug Gauges for NPT PipeThreads with Calibration Certificate

Threaded Plug Gauges

Threaded Plug Gauges for NPT Pipe Threads

Threaded Plug Gauges with Calibration Certificate

Master Ring Gauges

Threaded Ring Gauges with Calibration Certificate

Threaded Ring Gauges

Threaded Ring Gauges for NPT PipeThreads with Calibration Certificate

Threaded Ring Gauges for NPT Pipe Threads

Ring Gauges for Outside Diameters

Thread Gauges for Lug Nuts

Thread Gauges for Lug Nuts

Gear Tooth Pitch Identifiers

Gear Tooth Pitch Identifiers

Wall-Mount Thread-It Screw,
Bolt, and Nut Size Identifiers

Threaded Plug Gauges for NPT Pipe
Threads with Calibration Certificate

Threaded Ring Gauges for NPT Pipe
Threads with Calibration Certificate