*Recommend using diamond file, when you are fixing.

・Please apply a file with indicate 45 degrees, when the cutting lip scoops up wood chips has become blunt.

・Please apply a file to reappear a beautiful semicircular axis, since the top of the spur has been worn away and becomes short. Also, you are not able to drill with accurate circle and the resistance will be increased if the cutting lip does not become like a cutter blade when you apply a file.

・If the part of screw tip (induction screw) is made, the pull-in will be revived, but at the same time, please be careful that the screw tip may become thinner and missing. (It is better not to touch when pulling lightly.)

Conditions which are not able to re polish or reuse

① Either a bend or defect of the spur or cutting lip.

② Either a bend or break of the spiral part.

③ Either a bend or break of the shank part.

④ It does not draw circle accurately when the wide ‘B’ became half- length of the wide ‘A’(See diagram below).