FEEDS FOR HSS TWIST DRILLS

DIAMETER  IN.

FEED, IPR

UNDER 1/8"

0.001-0.002

1/8 -1/4"

0.002-0.004

1/4 - 1/2"

0.004-0.007

1/2 - 1"

0.007-0.015

OVER 1"

0.015-0.025

SPEEDS FOR HSS TWIST DRILLS

MATERIAL

Speed, sfm 

Aluminum alloys

200-300

Brass, bronze

150-300

High-tensile bronze

70-150

Zinc-base die castings

300-400

High-temp alloys, solution-treated & aged

7-20

Cast iron
   soft
   medium hard
   hard chilled
   malleable

75-125
50-100
10-20
80-90

Magnesium alloys

250-400

Monel or high-Ni steel

30-50

Bakelite and similar

100-300

Steel, 
   0.2%-0.3% C
   0.4%-0.5% C
   tool, 1.2$ C
   forgings
   alloy, 300-400 Bnh

80-100
70-80
50-60
40-50
20-30

High-tensile steel,
   heat treated to 35-40 Rc
   heat treated to 40-45 Rc
   heat treated to 45-50 Rc
   heat treated to 50-55 Rc

30-40
25-35
15-25
7-15

Maraging steel,
   heat treated
   annealed

7-20
40-55

Stainless steel
   free machining
   Cr-Ni, non hardenable
   Straight-Cr, martensitic

30-100
20-60
10-30

Titanium
   commercially pure
   6AI-4V. annealed
   6AI-4V, solution-trt & aged

50-60
25-35
15-20

Wood

300-400