Recommended Tool Speed Chart

Recommended Tool Speeds for High Speed Tooling

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.