薄鋼電線管ねじ　＜ねじ規格＞　ctc　～うすこうでんせんかんねじ～ | オーエスジー

As a symbol for the thread, it is represented as CTC.

* Please note that there is also a standard called "CTG" thick steel conduit thread, which is easy to make a mistake.
There are no standard stock products for both taps and gauges, and special products are supported.

If you are dealing with special items, please contact OSG through the trading company you usually do business with.