Different ways during boring ban to erect strict rules for steps and speeds. Standard guidelines count for typical materials. They base on safe values, that you can reach by means of manual or self-feed drill, machine or device with high speed steel (HSS).
Some indications assume use of right coolant. You advises to use soluble oil or air spray for keep the drill cool, especially at aluminum, brass, cast iron, copper and steel alloys.
HSS Drill Speeds and Feeds for Common Metals
For soft steel the advised cutting speed for HSS reach 30 meters in minute. For 1.6 mm drill of 52-size the maximum revolutions for minute in soft steel are 5900. Bearing through 1/4-inch soft steel, HSS requires much less of pace with liquid, around 380 rpm.
For 1/4-inch HSS drill the ideal or maximum rpm can be 900.
Stainless steel requires separate setups. For M2 HSS in 304/316 stainless the speed ranges between 8 (14 m/me or 26), 46 SFM. Nice HSS-drill in 316L either duplex stainless reach 45…
52 SFM. For 3 mm drill in those materials you uses step of around 2 thou each revolution. Life of the tool is much more short than in 1018-steel.
Here minimal cutting time of 60 minutes are usual. Less deep or shorter boring occasionally extends tool life, although it grows the cycle time.
Other materials and tools require special rules. For Ø10 HSS-drill in EN21 you choose 12. 15 m/me cutting speed with common pecking, because the material attaches to the drill. For 0.500-inch spot drill in 6061-aluminium offers you 420 SFPM, so around 3200 rpm, 1.64 HP and step of 36 IPM.
You would can half that to 1600 RPM for second spot boring. For A2 with HSS-drill typical speed is 85 SFM with 0.007-inch step each revolution, what gives almost 650 RPM. Optimume maybe 45 SFM with 0.015-inch step each revolution.
Common HSS with 118° peak tolerates 50, 60 feet in minute. In 50 feet/minute 1/2-inch drill runs in 375 rpm with 0.007, 0.012-inch step each revolution. #7 drill reaches 955 rpm with 0.003, 0.006-inch step each revolution.
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