Chip loads are important for several reasons. Heat is generated during the machining process. The proper size chip removes heat from the tooling surface, extending the tool life and quality of cut. Proper chip sizes also are important to prevent tool breakage and injury.
The chip load is a measurement of the thickness of material removed by each cutting edge during a cut. This can then be used to calculate new set ups.
Calculation are as follows: Chip Load = Feed Rate (inches per minute) / (RPM x number of flutes).
Example: a 1/2" diameter tool cutting particle board has a suggested chip load rate of .025"-.027". We'll use .025" for the example. We'll also use an RPM of 16000. The tool in our example has 2 flutes. Each rotation will result in 2 flutes cutting .025" each. 2 x .025" = .05" per rotation. 16000 x .05" = 800" per minute for the feed rate.
Chip loads are based on material thickness of average size for cutting edge length of tool. These recommendations do not apply to thicker material or tools with long cutting-edge lengths. These chip loads are only a recommended starting point and may not accommodate all circumstances. Tooling damage may still occur and use of this chart does not warranty against tool breakage or injury.
Tool Diameter | Hard Wood | Softwood/Plywood | MDF/Particle Board | High Pressure Laminate | Phenolic/Paperstone |
| 1/8" | .003” - .005” | .004” - .006” | .004” - .007” | .003” - .005” | n/a |
| 1/4" | .009” - .011” | .011” - .013” | .013” - .016” | .009” - .012” | .004” - .006” |
| 3/8" | .015” - .018” | .017” - .020” | .020” - .023” | .015” - .018” | .006” - .008” |
| 1/2" & up | .019” - .021” | .021” - .023” | .025” - .027” | .023” - .025” | .010” - .012” |
Tool Diameter | Hard Plastic | Soft Plastic | Solid Surface | Acrylic | Aluminum |
| 1/8” | .002” - .004” | .003” - .006” | .002” - .004” | .003” - .005” | .003” - .004” |
| 1/4" | .006” - .009” | .007” - .010” | .006” - .009” | .008” - .010” | .005” - .007” |
| 3/8" | .008” - .010” | .010” - .012” | .008” - .010” | .010” - .012” | .006” - .008” |
| 1/2” & up | .010” - .012” | .012” - .016” | .010” - .012” | .012” - .015” | .008” - .010” |