| 摘要 |
The tapping section (31) is so formed that its inner dia. (D) corresponds to the dia. of the drilled hole. The tool has rear and front guide sections (32,33) which have the same dia. as the tapping section dia.. The front guide section (33) has a length of at least 40 mm, and the rear guide section (32) a length of at least 100 mm. The distance between the tapping section and the chuck to which the tool is anchored is at least as long as the bolt dia. in the drilled hole direction to achieve a guide function so that the tool central axis is adjusted and maintained coaxial with the drilled hole central axis during the whole tapping operation. |
