Metal Drill Feeds and Speeds –
Different drilling conditions make it impossible to develop any rigid rules for feeds and speeds when drill metal materials
The following tables contain guidelines that can be utilized when drilling standard metal 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 90 surface feet per minute in 100 Brinell hardness material, and the speed be reduced 10 surface feet per minute for each additional 50 points of Brinell hardness.
• Feed and speed rates should be reduced up to 45 to 50% when drilling holes deeper than 4 drill diameters.