• Depth of cut is 3mm or 0.118 inches

• Cut diameter is 6mm or 0.236 inches

• Cut length is 30mm or 1.181 inches

• To calculate the spindle speed = π x Diameter of workpiece.

• This equal to 3.14 x 12mm = 37.68 RPM

What is Feed Rate (IPR)?

IPR - Also called, feedrate, or called simply feed, is the relative velocity at which the cutter is advanced along the workpiece. The units are almost always distance per spindle revolution (inches per revolution [in/rev or IPR] or millimeters per revolution [mm/rev]).

Suggested Speeds Roughing Cut (IPR):

• Mild Steel: .005 - .020 inches

• Aluminium: .005 - .020 inches

• Brass: .005 - .020 inches

Suggested Speeds Finishing Cut (IPR):

• Mild Steel: .002 - .004 inches

• Aluminium: .002 - .004 inches

• Brass: .002 - .004 inches

Spindle Speed: 37.68 (RPM)

Cutting feed: 0.020 (IPR)

Feed rate: 0.754 (IPM)

Cut Length: 1.181 (in)

Cut Time: 1.566 (mins)

• Cutting feed - The distance that the cutting tool or workpiece advances during one revolution of the spindle, measured in inches per revolution (IPR). In some operations the tool feeds into the workpiece and in others the workpiece feeds into the tool. For a multi-point tool, the cutting feed is also equal to the feed per tooth, measured in inches per tooth (IPT), multiplied by the number of teeth on the cutting tool.

• Cutting speed - The speed of the workpiece surface relative to the edge of the cutting tool during a cut, measured in surface feet per minute (SFM).

• Spindle speed - The rotational speed of the spindle and the workpiece in revolutions per minute (RPM). The spindle speed is equal to the cutting speed divided by the circumference of the workpiece where the cut is being made. In order to maintain a constant cutting speed, the spindle speed must vary based on the diameter of the cut. If the spindle speed is held constant, then the cutting speed will vary.

• Feed rate - The speed of the cutting tool's movement relative to the workpiece as the tool makes a cut. The feed rate is measured in inches per minute (IPM) and is the product of the cutting feed (IPR) and the spindle speed (RPM).

• Axial depth of cut - The depth of the tool along the axis of the workpiece as it makes a cut, as in a facing operation. A large axial depth of cut will require a low feed rate, or else it will result in a high load on the tool and reduce the tool life. Therefore, a feature is typically machined in several passes as the tool moves to the specified axial depth of cut for each pass.

• Radial depth of cut - The depth of the tool along the radius of the workpiece as it makes a cut, as in a turning or boring operation. A large radial depth of cut will require a low feed rate, or else it will result in a high load on the tool and reduce the tool life. Therefore, a feature is often machined in several steps as the tool moves over at the radial depth of cut.

www.destinytool.com/speeds-feeds.html

www.micro-machine-shop.com/SFM_Formulae_Chart_2.pdf