MITSUBISHI MATERIALS CORPORATION Formulas for Cutting Power

MITSUBISHI MATERIALS CORPORATION

Technical Information
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Formulas for Cutting Power

FORMULAS FOR CUTTING POWER

CUTTING SPEED (vc)

	vc(SFM):Cutting Speed Dm (inch):Workpiece Diameter π(3.14):Pi n (min-1):Main Axis Spindle Speed	Check the item you want to calculate, input values in the two boxes, and then press the Calculate button. n (min-1) Dm (inch) vc (SFM)
(Problem) : What is the cutting speed when main axis spindle speed is 700 min-1 and external diameter is φ2" ? (Answer): Substitute π=3.14, Dm=2, n=700 into the formulae. vc=π× Dm×n÷12=3.14×2×700÷12=366.33SFM Cutting speed is 366.33SFM.

FEED(f)

	f (IPR):Feed per Revolution I (inch/min):Cutting Length per Min. n (min-1):Main Axis Spindle Speed	Check the item you want to calculate, input values in the two boxes, and then press the Calculate button. I (inch/min) n (min-1) f (IPR)
(Problem): What is the feed per revolution when main axis spindle speed is 500min-1and cutting length per minute is 120 mm/min? (Answer): Substitute n=500, I=4.72 into the formulae. f=I÷n=4.72÷500=.009IPR The answer is .009IPR.

CUTTING TIME (Tc)

	Tc (min):Cutting Time Im (inch):Workpiece Length I (inch/min):Cutting Length per Min.	Input the values lm(inch) l (inch/min) Tc (min) second (s)
(Problem): What is the cutting time when 4inch workpiece is machined at 1000min-1 with feed= .008IPR ? (Answer): First, calculate the cutting length per min. from the feed and spindle speed. I=f×n=.008×1000=8inch/min Substitute the answer above into the formulae. Tc=Im÷I=4÷8=0.5min 0.5x60=30(sec.)The answer is 30 sec.

THEORETICAL FINISHED SURFACE ROUGHNESS (h)

	h (μinch):Finished Surface Roughness f (IPR):Feed per Revolution Re (inch):Insert Corner Radius	Input the values f (IPR) Re (inch) h(μinch)
(Problem): What is the theoretical finished surface roughness when the insert corner radius is .031inch and feed is .008 IPR ? (Answer): Substitute f=.008IPR,R=.031 into the formulae. h =(.008)2÷(8×.031)×10002=258μinch The theoretical finished surface roughness is .258μinch.