Calculate the feed in inches per minute for O1 tool steel with a cutting speed of 55 SFM, using an HSS end mill with a diameter of 0.875 inches and a chip load per tooth of 0.008 inches.

To calculate the feed in inches per minute (IPM), the formula used is:

[ \text{Feed} = \text{RPM} \times \text{Number of Teeth} \times \text{Chip Load per Tooth} ]

First, we need to determine the RPM (Revolutions Per Minute) using the cutting speed (SFM - Surface Feet per Minute) and the diameter of the end mill. The formula for RPM is:

[ \text{RPM} = \frac{\text{Cutting Speed (SFM)} \times 12}{\pi \times \text{Diameter (inches)}} ]

Putting in the provided values:

• Cutting speed: 55 SFM

• Diameter of the end mill: 0.875 inches

Substituting these values into the formula:

[ \text{RPM} = \frac{55 \times 12}{\pi \times 0.875} ]

Calculating this:

1. Multiply 55 by 12:

• ( 55 \times 12 = 660 )

2. Calculate (\pi \times 0.875):

• Approximately ( 3.14159 \times 0.