In these cases, the metal removal rate is far greater than the capacity of most of the shoulder tools, but the power consumption will increase proportionally.
However, in most cases, when the horsepower is sufficient, the shoulder tool is better than a button cutter. This observation comes from the fact that a square shoulder insertion usually has a cutting edge length of 15-17 mm, which maintains a uniform thickness of the chip in the cross-section of the chip. A key cutter will allow deep cutting, but because of its circular shape, the increase of cutting depth will increase the chip thickness. This phenomenon results in very high cutting force and tool pressure, creating the possibility of premature insertion of wear, insert fragments or workpiece movements.
This creates an acceptable metal removal rate, even for a light machine. However, the shoulder tool will be limited to any depth that the machine allows, limiting the removal of the metal.
Rigidity is a factor in machine tool and workpiece installation. A box-type machine tool will allow more cuts than linear methods. A workpiece is set up and solid, and a good distributed clamping will allow more tool pressure than an unsupported section (for example, if part is wider than vise). These problems are related to tool selection.
In terms of mechanical stiffness, a good rule of thumb is that in the rigid machine, square shoulder tool will flourish, and a button will be in a less rigid tool machine is more satisfactory. The main reason for this phenomenon is the tool geometry. The flat shoulder tool, which has a 90-point front edge, will generate mainly radial cutting force and provide depth of potential recutting. Heavy cutting requires good machine spindle and mode rigidity, or vibration is almost certain to occur.
There is a sharper edge (Angle) on the shoulder tool,
