Drill Feed Rate Chart (IPR by Diameter)

What it is

A drill's feed is set in inches per revolution (IPR), the distance the drill advances each turn. Feed rate on the machine is:

• Feed (IPM) = RPM × IPR
• Metric: vf (mm/min) = n × f (mm/rev)

The ranges below are the long-standing shop starting points for general-purpose HSS jobber drills in steel. They scale with drill diameter because a larger drill has a stronger web and longer cutting edges.

How to use it

Set RPM from the SFM chart first. Then pick the feed range for the drill diameter. Start in the middle of the range, toward the low end for hard or tough material and toward the high end for free-machining material.

Starting feed for HSS twist drills

Example: a 3/8 in drill at 1,019 RPM and .005 IPR feeds at about 5.1 IPM.

Key points

• Carbide and coated drills have their own feed and speed data; use the drill maker's tables.
• Hand-fed drill presses: a steady chip that curls from both flutes is the goal. Long stringy chips mean feed is light; blue chips mean speed is high.
• Peck deep holes (over about 3 to 4 diameters for standard drills) to clear chips, unless the drill is designed for deep holes.
• Reduce feed as the drill breaks through thin or sheet material to prevent grabbing.

Common mistakes

• Feeding too lightly in stainless or other work-hardening alloys, which glazes the hole.
• Setting feed in IPM directly from this chart without multiplying by RPM.
• Using the same feed for a long-series drill as for a jobber drill. Longer drills flex and need less.

Governing standards: None. Drill manufacturer's recommendations govern for specific drills and materials.

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.