# Speed and Feed Selection 300

This class identifies the various speed and feed values used with the lathe and mill and describes how to convert these variables. Includes an Interactive Lab.

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## Class Details

Class Name:
Speed and Feed Selection 300
Description:
This class identifies the various speed and feed values used with the lathe and mill and describes how to convert these variables. Includes an Interactive Lab.
Version:
1.0
Difficulty:
Number of Lessons:
14
Spanish, Chinese
Related 2.0 Classes:
Speed and Feed for the Lathe 301, Speed and Feed for the Mill 311

## Class Outline

• Objectives
• The Importance of Speed and Feed
• Factors Determining Speed and Feed
• Speed and Feed Reference Sources
• Manual vs. CNC Machines
• Selecting Speed for the Lathe
• Constant Surface Speed
• Selecting Feed for the Lathe
• Lathe Example
• Selecting Speed for the Mill
• Selecting Feed for the Mill
• Mill Example
• Optimizing Speeds and Feeds
• Summary

## Objectives

• Describe the relationships between cutting speed, workpiece hardness, and heat.
• List variables that affect speed and feed selection.
• Describe appropriate information sources for selecting speeds and feeds.
• Distinguish between speed and feed selection for manual and CNC machines.
• Distinguish between the various units used to determine speed on the lathe.
• Describe the relationship between constant surface speed and rpm.
• Distinguish between the various units used to determine feed on the lathe.
• Solve for the correct speed value on the lathe using the appropriate formula.
• Solve for the correct speed value on the mill using the appropriate formula.
• Distinguish between the various units used to determine feed on the mill.
• Solve for the correct feed value on the mill using the appropriate formula.
• Identify common factors that necessitate adjustments to speed and feed values.

## Glossary

Vocabulary Term Definition
chip load Another term for feed per tooth that refers to the thickness of chip material removed by the cutting edge of a tool.
CNC machine A sophisticated machine tool run by a computer that can perform mulitiple machining operations in the same setup with a variety of tools. CNC machines require a programmed speed and feed rate value.
column-and-knee mill The original and most basic type of mill that is used to machine flat or rectangular workpieces.
constant surface speed A mode on a CNC lathe that adjusts the spindle rpm as the tool travels toward and away from the spindle's axis.
depth of cut The thickness of material removed by one pass of the cutting tool.
engine lathe The original and most basic type of manual lathe that is used to make cylindrical workpieces.
feed The rate that either the workpiece or cutting tool changes in position during the length of the cut. Feed typically defines a linear or contour movement.
feed per revolution The linear distance that a tool advances during one rotation of the workpiece or cutting tool. On the mill, feed per revolution (fpr) may be used to convert from feed per tooth (fpt) to either inches per minute (ipm) or millimeters per minute (mm/min).
feed per tooth The thickness of chip material that each cutting edge of a tool removes with one pass.
hardness The ability of a material to resist scratching, indentation, or penetration. Workpiece materials with increased hardness generate more heat and are more difficult to machine.
horsepower A unit of power used to describe machine strength. A machine with increased horsepower has a spindle that can exert a greater amount of force.
inch per revolution The distance in inches that the tool advances during one complete revolution of the workpiece. Inch per revolution (ipr) is an English measurement for feed on the lathe.
inches per minute The distance in inches that the entire tool or workpiece advances in one minute. Inches per minute (ipm) is an English measurement for feed of a rotating cutting tool on the mill or lathe.
live tooling Rotating power-driven cutting tools, such as end mills and drills, that are held in the turret of a lathe. Live tools can perform machining operations off the part centerline while the workpiece is held stationary in the spindle.
millimeter per revolution The distance in millimeters that the tool advances during one complete revolution of the workpiece. Millimeter per revolution (mm/rev) is a metric measurement for feed on the lathe.
millimeters per minute The distance in millimeters that the entire tool or workpiece advances in one minute. Millimeters per minute (mm/min) is a metric measurement for feed of a rotating cutting tool on the mill or lathe.
part program A series of numerical instructions used by a CNC machine to perform the necessary sequence of operations to machine a specific workpiece.
pi A special constant value that relates the diameter of a circle to its circumference. Pi is roughly 3.14 and is used to find the circumference and area of a circle.
revolutions per minute The number of revolutions that a spindle or cutting tool completes in one minute. Revolutions per minute (rpm) is a measurement of speed in both English and metric systems.
roughing A cutting pass that emphasizes high material removal rates at the possible sacrifice of surface finish or accuracy.
speed The rate that the workpiece surface and cutting tool pass each other at the point of contact. Speed typically defines a rotational movement.
surface feet per minute The distance in feet that the workpiece surface or cutting edge travels in one minute. Surface feet per minute (sfm) is an English measurement for speed.
surface meters per minute The distance in meters that the workpiece surface or cutting edge travels in one minute. Surface meters per minute (smm) is a metric measurement for speed.