Gauge inspection of internal threads for pipes ~ What is the gauge to inspect the internal thread of RP1/4? ~
The gauge measuring the internal thread of Rp1/4 uses a tapered plug gauge of R.
Gauge determines the "fit" of the screws.
Therefore, we use a gauge that has the same shape as the person we are flaming into.
| Types of screws | Use gauge | |
| Current JIS | Parallel internal thread |
Tapered screw plug gauge |
| Conventional JIS | Parallel internal thread |
Tapered screw plug gauge |

* Parallel screws are judged by tapering gauge .
(FAQID:240)