Thread Ring Gauges | McMaster-Carr

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Threaded Ring Gauges

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

The part is within tolerance if it’s easy to thread a go gauge onto the part but difficult to thread a no-go gauge more than two turns.

Go gauges check the maximum external thread size.

No-go gauges check the minimum external thread size.

Threads have different classes of fit. Thread fit designates the tightness or looseness of the mating threads. For example, inch threads with a 3A fit have tighter tolerances than threads with a 2A fit.

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

Inch

Go Gauge
Thread Size	Thread Type	Hardness	Material	Choose a For Thread Fit	Pitch Dia. Tolerance		Each
Class X
0-80	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0002" to 0"	00000000	0000000
1-72	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0002" to 0"	00000000	000000
2-56	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0002" to 0"	00000000	000000
3-48	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0002" to 0"	00000000	000000
4-40	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0002" to 0"	00000000	000000
4-48	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0002" to 0"	00000000	000000
5-40	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0002" to 0"	00000000	000000
6-32	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
6-40	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0002" to 0"	00000000	000000
8-32	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
8-36	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0002" to 0"	00000000	000000
10-24	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
10-32	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
12-24	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
1/4"-20	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
1/4"-28	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
5/16"-18	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
5/16"-24	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
3/8"-16	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
3/8"-24	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
7/16"-14	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
7/16"-20	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
1/2"-13	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
1/2"-20	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
9/16"-18	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
5/8"-11	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
5/8"-18	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
3/4"-10	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
3/4"-16	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
7/8"-9	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
7/8"-14	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
1"-8	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0004" to 0"	00000000	000000
1"-12	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
1"-14	UNS	Rockwell C60	Tool Steel	Class 3A	-0.0003" to 0"	00000000	000000
1 1/8"-12	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
1 1/4"-7	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0004" to 0"	00000000	000000
1 1/4"-12	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	-0.0003" to 0"	00000000	000000
No-Go Gauge
Class X
0-80	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0002"	00000000	000000
1-72	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0002"	00000000	000000
2-56	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0002"	00000000	000000
3-48	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0002"	00000000	000000
4-40	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0002"	00000000	000000
4-48	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0002"	00000000	000000
5-40	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0002"	00000000	000000
6-32	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
6-40	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0002"	00000000	000000
8-32	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
8-36	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0002"	00000000	000000
10-24	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
10-32	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
12-24	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
1/4"-20	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
1/4"-28	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
5/16"-18	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
5/16"-24	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
3/8"-16	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
3/8"-24	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
7/16"-14	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
7/16"-20	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
1/2"-13	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
1/2"-20	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
9/16"-18	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
5/8"-11	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
5/8"-18	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
3/4"-10	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
3/4"-16	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
7/8"-9	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
7/8"-14	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
1"-8	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0004"	00000000	000000
1"-12	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
1 1/8"-12	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000
1 1/4"-7	UNC	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0004"	00000000	000000
1 1/4"-12	UNF	Rockwell C60	Tool Steel	Class 2A, Class 3A	0" to 0.0003"	00000000	000000

Metric

Go Gauge
Thread Size	Pitch	Hardness	Material	For Thread Fit	Pitch Dia. Tolerance		Each
Class X
M1.6	0.35 mm	Rockwell C60	Tool Steel	Class 6g	-0.005mm to 0mm	000000000	0000000
M2	0.4 mm	Rockwell C60	Tool Steel	Class 6g	-0.005mm to 0mm	000000000	000000
M2.5	0.45 mm	Rockwell C60	Tool Steel	Class 6g	-0.005mm to 0mm	000000000	000000
M3	0.5 mm	Rockwell C60	Tool Steel	Class 6g	-0.005mm to 0mm	000000000	000000
M3.5	0.6 mm	Rockwell C60	Tool Steel	Class 6g	-0.005mm to 0mm	000000000	000000
M4	0.7 mm	Rockwell C60	Tool Steel	Class 6g	-0.005mm to 0mm	000000000	000000
M5	0.8 mm	Rockwell C60	Tool Steel	Class 6g	-0.008mm to 0mm	00000000	000000
M6	1 mm	Rockwell C60	Tool Steel	Class 6g	-0.008mm to 0mm	000000000	000000
M8	1 mm	Rockwell C60	Tool Steel	Class 6g	-0.008mm to 0mm	00000000	000000
M8	1.25 mm	Rockwell C60	Tool Steel	Class 6g	-0.008mm to 0mm	000000000	000000
M10	1.25 mm	Rockwell C60	Tool Steel	Class 6g	-0.008mm to 0mm	000000000	000000
M10	1.5 mm	Rockwell C60	Tool Steel	Class 6g	-0.008mm to 0mm	000000000	000000
M12	1 mm	Rockwell C60	Tool Steel	Class 6g	-0.008mm to 0mm	000000000	000000
M12	1.25 mm	Rockwell C60	Tool Steel	Class 6g	-0.008mm to 0mm	00000000	000000
M12	1.5 mm	Rockwell C60	Tool Steel	Class 6g	-0.008mm to 0mm	000000000	000000
M12	1.75 mm	Rockwell C60	Tool Steel	Class 6g	-0.008mm to 0mm	000000000	000000
M14	1.5 mm	Rockwell C60	Tool Steel	Class 6g	-0.008mm to 0mm	000000000	000000
M16	1.5 mm	Rockwell C60	Tool Steel	Class 6g	-0.008mm to 0mm	000000000	000000
M16	2 mm	Rockwell C60	Tool Steel	Class 6g	-0.008mm to 0mm	000000000	000000
M18	1.5 mm	Rockwell C60	Tool Steel	Class 6g	-0.008mm to 0mm	000000000	000000
No-Go Gauge
Class X
M1.6	0.35 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.005mm	000000000	000000
M2	0.4 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.005mm	000000000	000000
M2.5	0.45 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.005mm	000000000	000000
M3	0.5 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.005mm	000000000	000000
M3.5	0.6 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.005mm	000000000	000000
M4	0.7 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.005mm	000000000	000000
M5	0.8 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.008mm	000000000	000000
M6	1 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.008mm	000000000	000000
M8	1 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.008mm	000000000	000000
M8	1.25 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.008mm	000000000	000000
M10	1.25 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.008mm	000000000	000000
M10	1.5 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.008mm	000000000	000000
M12	1 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.008mm	000000000	000000
M12	1.25 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.008mm	000000000	000000
M12	1.5 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.008mm	000000000	000000
M12	1.75 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.008mm	000000000	000000
M14	1.5 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.008mm	000000000	000000
M16	1.5 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.008mm	000000000	000000
M16	2 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.008mm	000000000	000000
M18	1.5 mm	Rockwell C60	Tool Steel	Class 6g	0mm to 0.008mm	000000000	000000

Threaded Ring Gauges with Calibration Certificate

A certificate of calibration traceable to NIST states that these gauges have passed a test for accuracy. They’re for checking a part’s external threads to ensure they fall within tolerance.

A part is within tolerance if it’s easy to thread a go gauge onto the part but difficult to thread a no-go gauge more than two turns.

Go gauges check the maximum external thread size.

No-go gauges check the minimum external thread size.

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

Inch

				Class 2A		Class 3A
Thread Size	Thread Type	Hardness	Material		Each		Each
Go Gauge
Class X
0-80	UNF	Rockwell C60	Tool Steel	00000000	0000000	00000000	0000000
1-64	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1-72	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
2-56	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
2-64	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
3-48	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
4-40	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
4-48	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
5-40	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
6-32	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
6-40	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
8-32	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
8-36	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
10-24	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
10-32	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
12-24	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
12-28	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1/4"-20	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1/4"-28	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
5/16"-18	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
5/16"-24	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
3/8"-16	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
3/8"-24	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
7/16"-14	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
7/16"-20	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1/2"-13	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1/2"-20	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
9/16"-18	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
5/8"-11	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
5/8"-18	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
3/4"-10	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
3/4"-16	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
7/8"-9	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
7/8"-14	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1"-8	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1"-12	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1"-14	UNS	Rockwell C60	Tool Steel	000000	00	00000000	000000
1 1/8"-12	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1 1/4"-7	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1 1/4"-12	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1 1/2"-12	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1 1/2"-6	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
No-Go Gauge
Class X
0-80	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1-64	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1-72	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
2-56	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
2-64	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
3-48	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
4-40	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
4-48	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
5-40	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
6-32	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
6-40	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
8-32	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
8-36	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
10-24	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
10-32	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
12-24	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
12-28	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1/4"-20	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1/4"-28	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
5/16"-18	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
5/16"-24	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
3/8"-16	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
3/8"-24	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
7/16"-14	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
7/16"-20	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1/2"-13	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1/2"-20	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
9/16"-18	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
5/8"-11	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
5/8"-18	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
3/4"-10	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
3/4"-16	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
7/8"-9	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
7/8"-14	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1"-8	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1"-12	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1 1/8"-12	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1 1/4"-7	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1 1/4"-12	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1 1/2"-12	UNF	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
1 1/2"-6	UNC	Rockwell C60	Tool Steel	00000000	000000	00000000	000000

Metric

					Go Gauge		No-Go Gauge
					Class 6g		Class 6g
Thread Size	Thread Type	Pitch	Hardness	Material		Each		Each
Class X
M1.6	Metric	0.35 mm	Rockwell C60	Tool Steel	00000000	0000000	00000000	0000000
M2	Metric	0.4 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M2.5	Metric	0.45 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M3	Metric	0.5 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M3.5	Metric	0.6 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M4	Metric	0.7 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M5	Metric	0.8 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M6	Metric	1 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M7	Metric	1 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M8	Metric	1 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M8	Metric	1.25 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M10	Metric	1.25 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M10	Metric	1.5 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M12	Metric	1 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M12	Metric	1.25 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M12	Metric	1.5 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M12	Metric	1.75 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M14	Metric	1.5 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M16	Metric	1.5 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M16	Metric	2 mm	Rockwell C60	Tool Steel	00000000	000000	00000000	000000
M18	Metric	1.5 mm	Rockwell C60	Tool Steel	00000000	000000	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

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