This Drill Point Sharpening Gage is offered complimentary in each Engineers Black Book

Drill Point Sharpening Methodology

Step 1  //  Hints for Hand Grinding Twist Drills
 
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
 
Step 2  //  Line Drill up with Gage against desired Tip Angle
 
The DRILL POINT SHARPENING GAGE is the tool most frequently used to check the drill point during the sharpening operation
 
Step 3  //  Drill Test and the Effects of incorrect grinding of the Drill Point
 

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



This Drill Point Sharpening Gage is offered complimentary in the following books:
Engineers Black Book - 2st Edition
Engineers Black Book - USA Edition
All other Engineers Black Book Language Editions



For all inquiries regarding this Drill Point Sharpening Gage: Click Here