Drilling Tools & Accessories

Suggested drill sizes listed in the table for Aluminium are within the minor diameter limits for HELI-FORM tapped holes. Alternate drill sizes are suggested for magnesium, steel and palstics to provide for maximum tap wear life. In the case of magnesium the larger size is recommended to allow for material close-in.

Since HELI-FORM Inserts are flexible, the class of FIT of the final assembly is a function of the tapped hole. The following class of FITS are recommended;

1) METRIC SERIES - Inserts 5H.
2) AMERICAN SERIES - iNSERTS 2B.

To remove the improper installed Insert place the blade of the EXTRACTING TOOL into the Insert and hit the top of the tool by hammer to bite the Insert. Then rotate anti-clockwise putting downward pressure and the Insert will come out of the hole

Rest the Tang Breaking Tool on the tang of the Inserts and give an impact blow on the top of the tool by a hammer. Tang will break perfectly.

Conventional shop practice and production procedure, speeds feeds and lubricants should be used in combination with proper fixturing and good tapping machines and tapping head

Accuracy of finish thread, when the the Insert is installed, is dependent upon the accuracy of the tapped hole. If the finish tapped hole gauges satisfactorily, the installed Insert will be within the Thread tolerance. It is therefore not necessary to guage the installed Inserts. After the Insert is installed the go Thread plug gauge may not enter freely, however the Insert will always sit itself when the bolt or screw is installed and tightened.