Shoulder milling operations include:
- Shoulder/ face milling
- Edging peripheral milling
- Shoulder milling of thin deflecting walls
Shoulder / face milling
What is successful shoulder / face milling?
Shoulder milling generates two faces simultaneously, which requires peripheral milling in combination with face milling. Achieving a true, ninety degree shoulder is one of the most important requirements. Shoulder milling can be performed by traditional square shoulder cutters, and also by using end milling cutters, long edge cutters and side and face milling cutters. Due to these numerous options, it is essential to consider the operational requirements carefully in order to make an optimal choice.
Choice of tools
Shoulder milling cutters
Shoulder face mills of conventional designs are often capable of milling “true”, 90 degree shallow shoulders. Many shoulder face mills are universal cutters, and can be used advantageously for making holes. They offer a good alternative to face milling cutters when milling axially deflecting surfaces or for milling close to vertical faces.
End milling cutters
The indexable insert and solid carbide end mills offer good solutions for shoulders requiring accessibility.
Long edge milling cutters
Long edge cutters are generally used for milling deeper shoulders.
How to apply
Milling of shallow shoulders
This frequently used operation is generally performed by shoulder face mills and end mills. A shallow cut allows for a larger radial cut. Often these cutters can replace face mills, in particular when the axial pressure on the component is a limitation, and when there is a demand for accessibility close to vertical faces or fixture sections. Oversized shoulder cutter options provide for optimal accessibility when milling shallow shoulders located deep.
Milling of deep shoulders
Use repeated passes with shoulder face mills and end mills. To minimize surface errors, such as scallops and transition-edges between the passes, a high precision cutter that is able to produce true 90º shoulders is an absolute requirement. If shoulder depth is smaller than 75% of the cutting edge length, the quality of the vertical surface does not normally require extra finishing.
Use a single pass with a long edge milling cutter
A long edge cutter is a good solution for deeper, larger and usually heavier shoulder milling applications. They have a high metal removal capacity, and are generally used for rough milling as the resulting surface texture is characterized by side milling at high feed rates.
These cutters make demands on:
- Spindle condition
- Chip evacuation
- Tool holding
Radial forces are considerable making this a tough side milling application.
Shorter long edge cutters are suitable for:
- Radially large but shallow shoulders.
- Full slotting at a depth equal to the diameter, which can make up for machine limitations
Longer versions are intended for:
- Milling of shoulders with moderate radial depth.
- Edging in powerful, stable machines