The calibrating plug gauge is mainly used for calibrating and debugging adjustable thread ring gauge. It is one of the special gauges in American standard. American standard ring gauge is divided into American standard British thread ring gauge and American standard metric thread ring gauge.

Common types of plug gauges are as follows:

0-80（0.060）UNF-2A

1-64(0.73)UNC-2A

1-72(0.73)UNF-2A

2-56(0.086)UNC-2A

2-64(0.086)UNF-2A

3-48(0.99)UNC-2A

3-56(0.99)UNF-2A

4-40(0.112)UNC-2A

4-48(0.112)UNF-2A

5-40(0.125)UNC-2A

5-44(0.125)UNF-2A

6-32(0.138)UNC-2A

6-40(0.138)UNF-2A

8-32(0.164)UNC-2A

8-36(0.164)UNF-2A

10-24(0.190)UNC-2A

10-32(0.190)UNF-2A

12-24(0.216)UNC-2A

12-28(0.216)UNF-2A

1/4-20UNC-2A

1/4-28UNF-2A

1/4-32UNEF-2A

5/16-18UNC-2A

5/16-24UNF-2A

5/16-32UNEF-2A

3/8-16UNC-2A

3/8-24UNF-2A

3/8-32UNEF-2A

7/16-14UNC-2A

7/16-20UNF-2A

7/16-28UNEF-2A

1/2-13UNC-2A

1/2-20UNF-2A

1/2-28UNEF-2A

9/16-12UNC-2A

9/16-18UNF-2A

9/16-24UNEF-2A

5/8-11UNC-2A

5/8-18UNF-2A

5/8-24UNEF-2A

11/16-24UNEF-2A

3/4-10UNC-2A

3/4-16UNF-2A

3/4-20UNEF-2A

13/16-20UNEF-2A

7/8-9UNC-2A

7/8-14UNF-2A

7/8-20UNEF-2A

15/16-20UNEF-2A

1/8-UNC-2A

1-12UNF-2A

1-14UNS-2A

1-20UNEF-2A

1 1/16-12UN-2A

1 1/16-18UNEF-2A

1 1/8-7UNC-2A

1 1/8-12UNF-2A

1 1/8-18UNEF-2A

1 3/16-12UN-2A

1 3/16-18UNEF-2A

1 1/4-7UNC-2A

1 1/4-12UNF-2A

1 1/4-18UNEF-2A

1 5/16-12UN-2A

1 5/16-18UNEF-2A

1 3/8-6UNC-2A

1 3/8-12UNF-2A

1 3/8-18UNEF-2A

1 7/16-12UN-2A

1 7/16-18UNEF-2A

1 1/2-6UNC-2A

1 1/2-12UNF-2A

1 1/2-18UNEF-2A

1 5/8-12UN-2A

1 3/4-12UN-2A

1 7/8-12UN-2A

2-12UN-2A

2 1/4-12UN-2A

2 1/2-12UN-2A