Viking Drill and Tool St. Paul MN
America's Finest High-Speed Steel Cutting Tools™
Proudly Manufactured in the USA
                             with globally sourced material

  • 240-CN CN-TECH™ Cryo/Nitride Jobber Drill Bit
  • Type 240-SS High Helix Flutes Drill Bit
  • High Speed Steel Titanium Aluminum Nitride Heavy-Duty NAS 907B
  • High Speed Steel Heavy-Duty NAS 907B Titanium Carbon Nitride
  • Cobalt M42 Titanium Nitride NAS 907B
  • Type
  • Cobalt Titanium Aluminum Nitride Jobber Drill Bit
  • Cobalt Titanium Aluminum Nitride Screw Machine Drill Bit
  • Type 40-AG HSS Super Premium Combination Drill & Tap


Norseman Drill and Tool - Feeds and Speeds Calculator
"Different drilling conditions make it impossible to develop any rigid rules for feeds and speeds."
The following tables contain guidelines which can be utilized when drilling standard materials. Also, the following “rules of thumb” can be used to determine proper feeds and speeds for drilling ferrous materials.
(NOTE: varying conditions can easily require adjustments ).

• Feed equals:  .001" per revolution for every 1/16" of drill diameter, plus or minus .001" on the total.

• Speed equals:  80 surface feet per minute in 100 Brinell hardness material and the speed should be reduced 10 surface feet per minute for each additional 50 points Brinell hardness.

• Feed and speed rates:  should be reduced up to 45-50‰ when drilling holes deeper than 4 drill diameters.

Feeds and Speeds - Formulas

R.P.M. = (3.8197 / Drill Diameter) x S.F.M.
S.F.M. = 0.2618 x Drill Diameter x R.P.M.
I.P.M. = I.P.R. (feed) x R.P.M. (speed)
Machine Time (seconds) = (60 x Feed minus Stroke) / I.P.M.

R.P.M. = Revolutions Per Minute I.P.R. = Inches Per Revolution
S.F.M. = Surface Feet Per Minute Feed Stroke = Drill Depth + 1/3
I.P.M. = Inches Per Minute Car Reamer = 1/2 Speed of Drill

Recommended Feeds of Various Diameter Drills

Diameter of Drill - Inches Feed Inches per Revolution
Under 1/8 .001 to .003
1/8 to 1/4 .002 to .006
1/4 to 1/2 .004 to .010
1/2 to 1 inch .007 to .015
1 inch and over .015 to .025

Typical Brinell Hardness Numbers for Metals

Materials Hardness Number
Soft brass 60
Mild Steel 130
Annealed Chissel Steel 235
White Cast Iron 415
Nitrided Surface 750

Recommended Speeds for Standard Materials
with High Speed Steel Drills

Material Recommended speed (SFM)
Aluminum and its Alloys 200-300
Brass and Bronze (Ordinary) 150-300
Bronze (High Tensile) 70-150
Die Casting (Zinc Base) 300-400
Iron-Cast (Soft)
   Cast (Medium Hard)
   Hard Chilled
Magnesium and its Alloys 250-400
Monel Metal or High-Nickel Steel, Stainless Steel 30-50
Plastics or Similar Materials 100-300
 Mild .2 Carbon to .3 Carbon
 Steel .4 Carbon to .5 Carbon
 Tool 1.2 Carbon
 Alloy - 300 to 400 Brinell

High Tensile (Heat Treated) (Consult your Material Supplier)