Drill Point Sharpening Gage With Imperial (Inch) Markings

ENGINEERS BLACK BOOK Drill Point Sharpening Gage

Procedure: The left hand thumb and forefinger is used as a pivot as illustrated and the back of the drill is held with the right hand and forefinger and rotated in a clockwise direction advancing the drill into the grinding wheel.

Points to Note:

• Keep the drill point constantly sharp
• Avoid excessive grinding pressures
• Avoid overheating the drill point
• Avoid sudden cooling of the drill point
• Use copious supply of coolant

Roughing
The periphery of the wheel should be
used for roughing-out of the drill point
if much metal must be ground away

Finishing
The side of the wheel should
be used for finishing

The DRILL POINT SHARPENING GAGE is the tool most frequently used to check the drill point during the sharpening operation

To test whether a drill has been properly sharpened,
drill a hole in soft material and observe the chip formation.
When properly sharpened, the chips will come out of the
flutes in curled spirals of equal length

Incorrect grinding causes the drill bit to run out of true, producing oversized and often, out-of-round holes.
This puts severe strain on the drill bit causing rapid wear and premature drill failure.

Lips of EQUAL lengths but UNEQUAL angles

Lips of UNEQUAL lengths but EQUAL angles

Lips of UNEQUAL lengths and UNEQUAL angles

SPECIFICATIONS

Size - Overall
80.00mm x 100.00mm
3.149" Inches x 3.936" Inches

Material
Aluminium

Thickness
0.9mm
0.0354" Inches

Hole Sizes
3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0 (mm)
1/8, 5/32, 3/16, 7/32, 1/4, 9/32, 5/16, 3/8, (Fraction)

Point Angles
60', 140', 118', 90', 130'

Weight
13.0 Grams
0.460 oz