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Table of Drilling Rotational Speeds

Drilling is one of the fundamental metalworking processes, requiring precise parameters to ensure tool effectiveness and durability. One of the key parameters is the drilling rotational speed. Choosing the appropriate rotational speed can significantly impact the quality of the work performed and the longevity of the tool used. In this article, we present a comprehensive table of drilling rotational speeds for various materials and tools.

What is the drilling speed?

Drilling speed is the number of revolutions a drill bit makes per minute (RPM – rotations per minute). The correct speed setting is crucial for effective drilling. An inadequate speed can lead to overheating of the tool, damage to the material and even breakage of the drill bit.

The main factors affecting speed selection:

  • Type of material
  • Drill diameter
  • Type of tool
  • Type of drilling operation

Drilling Speed Table

Material Coolant Drill Diameter (mm) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 RPM
Carbon structural steel up to 700 N/mm² Cooling oil, emulsion RPM 8000 4500 3500 3000 2800 2300 2000 1750 1500 1400 1250 1150 1050 950 900 875 820 770 700 700 660 620 580 560 530 500 460 440 420 400 380 360 340 320 300 280 260 240 220 200 180 RPM
Alloy steel up to 1000 N/mm² Cooling oil, emulsion RPM 7000 3500 2500 2300 2100 1750 1600 1300 1200 1050 950 875 820 750 700 650 620 600 525 525 490 460 430 420 400 380 350 335 320 300 290 280 270 260 250 240 230 220 210 200 190 RPM
Steel up to 1400 N/mm² Cooling oil, emulsion RPM 6000 2800 2000 1750 1600 1300 1200 1000 900 850 800 700 660 620 590 525 480 450 420 420 400 380 360 340 320 300 280 260 240 220 210 200 190 180 170 160 150 140 130 120 110 RPM
Cast iron above 250 N/mm² Air cooling RPM 4500 2200 1600 1400 1200 1000 900 750 700 600 550 500 460 420 400 375 340 300 280 280 260 240 220 200 180 160 150 140 130 120 110 100 95 90 85 80 75 70 65 60 55 RPM
Brass alloy Cooling oil, emulsion RPM 9000 7000 5500 4700 4000 3500 3100 2600 2400 2100 1900 1750 1600 1500 1400 1300 1200 1100 1050 1050 1000 950 900 850 800 750 700 650 600 550 500 475 450 425 400 375 350 325 300 275 250 RPM
Aluminum alloy Cooling oil, emulsion RPM 12000 9000 7000 6000 5000 4500 4000 3500 3000 2800 2600 2300 2100 2000 1900 1750 1650 1500 1400 1400 1350 1300 1250 1200 1120 1050 980 930 880 820 780 740 700 670 640 600 580 560 530 500 470 RPM
Bronze Cooling oil, emulsion RPM 10000 6000 4500 4000 3500 3000 2750 2300 2100 1900 1750 1600 1500 1400 1300 1200 1150 1050 950 950 900 850 800 760 730 700 660 630 600 570 540 515 490 475 460 440 420 400 380 360 340 RPM
Copper Cooling oil, emulsion RPM 11000 7500 6000 5000 4500 3700 3400 2900 2700 2300 2150 1900 1750 1650 1550 1400 1300 1200 1150 1150 1050 1000 950 900 850 800 770 720 680 640 600 575 550 525 500 475 460 440 420 400 380 RPM
Thermoplastic Air cooling, water RPM 15000 10000 8000 7000 6500 5000 4500 4000 3500 3200 3000 2700 2500 2400 2300 2000 1900 1800 1600 1600 1500 1400 1300 1200 1100 1070 1020 980 940 900 860 820 780 740 700 670 640 610 580 550 520 RPM
Thermosetting plastic Air cooling, water RPM 12000 9000 7000 6000 5000 4500 4000 3500 3000 2800 2600 2300 2100 2000 1900 1750 1650 1500 1400 1400 1350 1300 1250 1200 1120 1050 980 930 880 820 780 740 700 670 640 600 580 560 530 500 470 RPM

(Speeds are given as a guide. Depending on the specific situation and application, there may be differences.)

Selecting the right speed

To choose the right speed for your project, consider both the material you will be drilling and the diameter of the drill bit. The harder the material, the lower the rotational speed required. For softer materials, such as aluminum or plastics, higher speeds can be used.

Example of application

For drilling holes in mild steel with a diameter of 10 mm, the rotational speed should be reduced compared to drilling holes with a smaller diameter. For larger drill diameters, the speed should also be lower to avoid overheating of the tool.

See also: Metalworking services – Drilling

Why is the right speed important?

Using the right speed when drilling ensures:

  • Better hole quality
  • Longer tool life
  • Reduced risk of material damage
  • Time and cost savings

Remember: Always check the specifications of the tools and materials you are working on to select the optimal drilling parameters.

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