Recommended Tool Speeds for High Speed Tooling

These numbers are all conservative and based on what you can typically get away with on a manual or self-feed drill press or machine. The numbers for some materials presume the use of appropriate coolant. Higher quality tooling can often allow you to run faster RPM rates and/or more aggressive feed and thrust rates but typically require higher HP for the process as well.

Note that if you are using this chart to estimate the machine requirements for a multiple spindle drilling project, you will need to multiply some of the numbers by the number of holes you will be processing plus add a bit for internal gearing resistance, etc.

Dia. 1/16″ 1/8″ 3/16″ 1/4″ 5/16″ 3/8″ 1/2″ 5/8″ 3/4″ 1″
Aluminum RPM 10,000 6000 4000 3000 2400 2000 1500 1200 1000 750
HP .01 .07 .10 .20 .28 .28 .67 1.00 1.37 2.30
Feed .001 .003 .005 .007 .008 .009 .012 .014 .016 .018
Thrust 6 25 50 80 100 125 200 260 335 450
Brass RPM 10,000 6000 4000 3000 2400 2000 1500 1200 1000 750
HP .01 .05 .10 .18 .28 .41 .72 1.13 1.62 2.75
Feed .001 .002 .003 .004 .005 .006 .008 .010 .012 .014
Thrust 10 25 45 70 100 135 215 295 395 525
Cast Iron RPM 6000 3000 2000 1450 1150 975 725 600 500 375
HP .01 .04 .11 .18 .28 .38 .57 .80 1.10 1.75
Feed .001 .002 .004 .005 .006 .007 .008 .009 .010 .012
Thrust 15 40 100 150 200 260 350 480 550 800
Low Carbon Steel RPM 4300 2150 1450 1100 900 750 550 450 360 275
HP .01 .05 .12 .20 .30 .35 .68 1.05 1.50 2.10
Feed .001 .003 .005 .007 .008 .009 .012 .014 .016 .018
Thrust 30 80 145 230 340 440 700 1050 1300 2000
Stainless Steel RPM 3200 1550 1025 775 620 510 400 360 310 270
HP .01 .05 .12 .21 .40 .48 .85 1.45 2.05 3.1
Feed .001 .002 .003 .004 .005 .005 .007 .009 .010 .011
Thrust 40 100 180 290 425 465 780 1100 1500 1900
Plastic/Wood RPM 7000 4000 2700 2000 1600 1400 1000 800 700 550
HP .01 .07 .10 .20 .28 .28 .67 1.00 1.37 2.30
Feed .001 .002 .003 .004 .004 .005 .007 .009 .011 .015
Thrust 10 20 40 60 70 90 145 175 220 330

Dia. = Drill Diameter in Inches
HP = Horsepower
Feed = Feed in Inches per Revolution
Thrust = Thrust in lbs.

A typical drill press often has an RPM limitation of between 2000-3600 RPM. If the chart above specifies a higher RPM than your machine is capable of, it should not cause a problem to run at a lower RPM. For instance, many people drill 1/16″ holes at less than 10,000 RPM with no problems.

The process of drilling holes in metal or similar materials without coolant is possible but not suggested. In most metals, the RPM rate can be decreased to 25% of what is shown above. In stainless, the RPM rate must be decreased significantly more as stainless steel does not dissipate heat easily and will almost immediately ruin the tip of your tool. It is often helpful to take a heavier cut in stainless than a lighter one to keep the tip of the tool in “cool” material rather than near the surface that was recently heated up by the last pass of the tool tip.

Reaming generally runs at 2/3 or less the RPM of drilling. AutoDrill suggests the same horsepower rating in case the hole is undersized, etc. The last thing you want is to stall your machine or motor. Check with your reamer tool manufacturer for specific requirements and limits.

Tapping generally runs at around 1/3 to 1/4 the RPM of drilling. We suggests a minimum of 2-3 times the horsepower of drilling for standard tapping processes and higher numbers for flow or roll form tapping. Check with tap your tooling manufacturer for specific requirements and limits.

WHY DO MY TOOLS WEAR QUICKLY OR BREAK?

Note that excessive tool wear or breakage is often caused by one of the following:

  • Improper surface speeds
  • Improper feed rates
  • Improper cutting tool type or material (HSS vs TiN vs Carbide, etc.)
  • Dull tooling
  • Hard spots in the material such as scale, silica, etc.
  • Improper coolant or lubricant type
  • Inadequate coolant or lubricant (overall for chip removal, rubbing, etc.)
  • Inadequate coolant or lubricant (at the tip of the tooling)
  • The tool is not rigid enough (try drill bushings or guides, guide rods on the drilling machine, etc.)
  • Too deep of a cut without proper chip removal – Chip packing (try peck drilling, air blast or coolant through the tool options, etc.)
  • Tools that were manufactured or sharpened incorrectly. (watch those clearance, rake and lip angles as well as rough surfaces, etc.)

CALCULATING CYCLE TIME WHEN DRILLING:

We can help you lower your cycle time when drilling holes in a part or multiple parts. Generally, this is the calculation we use to figure out the time it will take to perform a process:

DEPTH divided by FEED = ROTATIONS.
ROTATIONS divided by RPM = MINUTES.
MINUTES multiplied by 60 = SECONDS it takes for the process.

(DEPTH = 30% of the diameter of the tool plus the thickness of the material)
Add in stroke up to product time
Add in stroke back to home time
Add in clamp and unclamp time
Add in any human factors, etc.
Add in time for potentially dull tooling, etc.
Add in time for less than adequate machine thrust, etc.

We use the charts above to estimate these numbers.

Please CONTACT US to discuss your application and receive prompt product cost, literature and technical help.