Ring Gauges for Outside Diameters
Check the outside diameter of shafts, rods, and other cylindrical objects to determine whether they’re in tolerance.
If your part can pass through a go gauge but cannot pass through a no-go gauge, it is within tolerance.
No-go gauges check the minimum outside diameter.
For technical drawings and 3-D models, click on a part number.
No-Go Gauges | |||||||
---|---|---|---|---|---|---|---|
Choose a Size | Increment | Surface Smoothness (RMS), microinch | Hardness | Material | Gauge Tolerance | Each | |
Class Z | |||||||
0.1501" to 0.2400" | 0.0001" | 8 | Rockwell C60 | Tool Steel | 0" to 0.0001" | 0000000 | 0000000 |
0.2401" to 0.3650" | 0.0001" | 8 | Rockwell C60 | Tool Steel | 0" to 0.0001" | 0000000 | 000000 |
0.3651" to 0.5100" | 0.0001" | 8 | Rockwell C60 | Tool Steel | 0" to 0.0001" | 0000000 | 000000 |
0.5101" to 0.8250" | 0.0001" | 8 | Rockwell C60 | Tool Steel | 0" to 0.0001" | 0000000 | 000000 |
0.8251" to 1.1350" | 0.0001" | 8 | Rockwell C60 | Tool Steel | 0" to 0.00012" | 0000000 | 000000 |
1.1351" to 1.5100" | 0.0001" | 8 | Rockwell C60 | Tool Steel | 0" to 0.00012" | 0000000 | 000000 |
1.5101" to 2.0100" | 0.0001" | 8 | Rockwell C60 | Tool Steel | 0" to 0.00016" | 0000000 | 000000 |
2.0101" to 2.5100" | 0.0001" | 8 | Rockwell C60 | Tool Steel | 0" to 0.00016" | 0000000 | 000000 |
Class X | |||||||
0.1501" to 0.2400" | 0.0001" | 4 | Rockwell C60 | Tool Steel | 0" to 0.00004" | 0000000 | 000000 |
0.2401" to 0.3650" | 0.0001" | 4 | Rockwell C60 | Tool Steel | 0" to 0.00004" | 0000000 | 000000 |
0.3651" to 0.5100" | 0.0001" | 4 | Rockwell C60 | Tool Steel | 0" to 0.00004" | 0000000 | 000000 |
0.5101" to 0.8250" | 0.0001" | 4 | Rockwell C60 | Tool Steel | 0" to 0.00004" | 0000000 | 000000 |
0.8251" to 1.1350" | 0.0001" | 4 | Rockwell C60 | Tool Steel | 0" to 0.00006" | 0000000 | 000000 |
1.1351" to 1.5100" | 0.0001" | 4 | Rockwell C60 | Tool Steel | 0" to 0.00006" | 0000000 | 000000 |
1.5101" to 2.0100" | 0.0001" | 4 | Rockwell C60 | Tool Steel | 0" to 0.00008" | 0000000 | 000000 |
2.0101" to 2.5100" | 0.0001" | 4 | Rockwell C60 | Tool Steel | 0" to 0.00008" | 0000000 | 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.
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.
No-Go Gauge | |||||||
---|---|---|---|---|---|---|---|
Class 2A | Class 3A | ||||||
Thread Size | Thread Type | Hardness | Material | Each | Each | ||
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 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 6g | ||||||
Thread Size | Thread Type | Pitch | Hardness | Material | Each | |
Class X | ||||||
M1.6 | Metric | 0.35 mm | Rockwell C60 | Tool Steel | 00000000 | 0000000 |
M2 | Metric | 0.4 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M2.5 | Metric | 0.45 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M3 | Metric | 0.5 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M3.5 | Metric | 0.6 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M4 | Metric | 0.7 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M5 | Metric | 0.8 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M6 | Metric | 1 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M7 | Metric | 1 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M8 | Metric | 1 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M8 | Metric | 1.25 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M10 | Metric | 1.25 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M10 | Metric | 1.5 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M12 | Metric | 1 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M12 | Metric | 1.25 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M12 | Metric | 1.5 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M12 | Metric | 1.75 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M14 | Metric | 1.5 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M16 | Metric | 1.5 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M16 | Metric | 2 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
M18 | Metric | 1.5 mm | Rockwell C60 | Tool Steel | 00000000 | 000000 |
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.
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.
No-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 | 0" to 0.0002" | 00000000 | 0000000 | |
1-72 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0002" | 00000000 | 000000 | |
2-56 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0002" | 00000000 | 000000 | |
3-48 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0002" | 00000000 | 000000 | |
4-40 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0002" | 00000000 | 000000 | |
4-48 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0002" | 00000000 | 000000 | |
5-40 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0002" | 00000000 | 000000 | |
6-32 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
6-40 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0002" | 00000000 | 000000 | |
8-32 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
8-36 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0002" | 00000000 | 000000 | |
10-24 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
10-32 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
12-24 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
1/4"-20 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
1/4"-28 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
5/16"-18 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
5/16"-24 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
3/8"-16 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
3/8"-24 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
7/16"-14 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
7/16"-20 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
1/2"-13 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
1/2"-20 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
9/16"-18 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
5/8"-11 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
5/8"-18 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
3/4"-10 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
3/4"-16 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
7/8"-9 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
7/8"-14 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
1"-8 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0004" | 00000000 | 000000 | |
1"-12 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
1 1/8"-12 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 | |
1 1/4"-7 | UNC | Rockwell C60 | Tool Steel | 0" to 0.0004" | 00000000 | 000000 | |
1 1/4"-12 | UNF | Rockwell C60 | Tool Steel | 0" to 0.0003" | 00000000 | 000000 |
No-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 | 0mm to 0.005mm | 000000000 | 0000000 |
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 |