UN Threads

      Home
News
Support
Helpful Links
Products
Services
Distributors

Prior to utilizing the NCT3 a pre-hole must be punched. You must always tap in the same sequence in which you pre-punched.

This chart is based on 65% - 70% thread engagement.

***********************************

Warning- Do not exceed .002 smaller pre-hole size than required. Serious tool damage may result.

************************************

Inches

Tap Size Material Thickness Punch Size
2-56 ALL .078
4-40 ALL .101
4-48 ALL .103
5-40 ALL .114
6-32 ALL .124
6-40 ALL .127
8-32 ALL .150
10-24 0-.08 .172
10-24 .09-.125 .173
10-24 .13-.19 .174
10-32 0-.08 .176
10-32 .09-.125 .177
10-32 .13-.16 .179
12-24 0-.08 .199
12-24 .09-.125 .201
12-24 .13-.19 .203
12-28 0-.09 .201
12-28 .09-.18 .202

 

bulletWhen tapping stainless steel increase the hole size by .001 -.002 on material .07 and thicker.
bulletA smaller H or D factor tap may be needed if tapped hole is too loose. Please see Tap Factor page for further explanation.
bulletIf tapping extrusions prehole is determined by material thickness not thickness of extruded hole.

 

Send mail to derek@dktech.net with questions or comments about this web site.
Copyright © 2002 d/k technologies
Last modified: March 25, 2007