USE/CARE OF HANDTOOLS & MEASURING TOOLS - OD1621 - LESSON 2/TASK 2
GRINDING A FLAT END PUNCH.
(a) Adjust the grinder rest so the end of the punch is opposite
the center of the abrasive wheel and can be ground square.
(b) Place the punch on the rest and feed the end of the punch into
the wheel. Rotate the punch during grinding to obtain a flat surface.
(c) Dip the punch in water frequently to preserve temper.
(d) Do not grind away more metal than is necessary to obtain a
flat, nick-free end.
(2) Cone Point Punches. Center and prick punches are ground to cone
points. The correct point angle for center punches is 90; the point angle
for prick punches is 30 (figure 112 on the following page). These angles
may be changed for special purposes.
(a) Adjust the grinder rest so that the end of the punch will be
ground at the desired angle.
(b) Place the punch on the rest and place the point on the
Rotate the punch during grinding to obtain cone shape
(figure 113 on the following page).