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Formulas for Milling

¨Cutting speed (vc)

* Divide by 1,000 to change to m from mm. vc (m/min): Cutting speed D (mm): Cutter diameter p (3.14): Circle ratio n:(min-1): Spindle speed Check the item you want to calculate, input values in the two boxes, and then press the Calculate button. D (mm) n (min-1) vc (m/min)
	(Example) What is the cutting speed when main axis revolution number is 350 min-1, and cutter diameter is ø125?
	(Answer) Substituting p=3.14, D=125 and n=350 into the formula. vc=(p×D×n)÷1000=(3.14×125×350)÷1000 =137.4(m/min) The cutting speed is 137.4 m/min.

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¨Feed per tooth (fz),Table feed (vf)

fz (mm/tooth): Feed per tooth z : Insert number vf (mm/min): Table feed per minute n (min-1): Spindle speed Check the item you want to calculate, input values in the three boxes, and then press the Calculate button. vf (mm/min) z n (min-1) fz (mm/tooth)
	(Example) The rotation speed of the main spindle is 500 min-1, the number of teeth is ten, and the table feed is 500 mm/min. The feed per tooth can be calculated as follows...
	(Answer) Substituting these values into the formula fz=Vf÷(z×n)=500÷(10×500)=0.1mm/tooth Thus the feed per tooth is approximately 0.1 mm/tooth.

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	(Example) What is the table feed when feed per tooth is 0.1mm/tooth, insert number is 10,and spindle speed is 500 min-1?
	(Answer) Substitute the above figures into the formula. vf=fz×z×n=0.1×10×500=500mm/min The table feed is 500 mm/min.

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¨Cutting time (Tc)

Tc (min): Cutting time vf (mm/min): Table feed per minute L (mm): Total table feed length (Workpiece length: l + Cutter diameter: D) Input the values L (mm) vf (mm/min) Tc (min) second (s)
	(Example) What is the cutting time required for finishing 100mm width and 300mm length surface of cast iron (JIS FC200) block when cutter diameter is ø200,insert number is 16,cutting speed is 125m/min,and feed per tooth is 0.25mm (Spindle speed 200 min-1)?
	(Answer) Calculate table feed per minute. vf=0.25×16×200=800mm/min Calculate total table feed length. L=300+200=500mm Substitute the above answers into the formula. Tc=500÷800=0.625(min) 0.625×60=37.5(sec) The answer is 37.5 seconds.