Why do some milling cutters have to have different pitches?
Milling cutter is a multi-cutting edge tool. The number of teeth (z) can be changed. There are some factors that can help to determine the pitch or number of teeth for different processing types. Material, workpiece size, overall stability, overhang size, surface quality requirements and available power are the factors related to processing. Tool-related factors include enough feed per tooth, at least two teeth in the cutting process at the same time, and the chip capacity of the tool, which are only a small part of them.
The pitch (u) of the milling cutter is the distance from the point on the cutting edge of the blade to the same point on the next cutting edge. Milling cutters are divided into sparse, dense and ultra-dense pitch milling cutters. Most Coke full milling cutters have these three options. See C-1102:1, sample of mould manufacturing. Dense pitch refers to having more teeth and suitable chip space, which can be cut with high metal removal rate. It is generally used for medium load milling of cast iron and steel. Dense pitch is the first choice of general milling cutters and is recommended for mixed production.
Sparse pitch means that there are fewer teeth and larger chip space around the milling cutter. Sparse tooth spacing is often used in roughing to finishing of steel. Vibration in steel processing has a great influence on the processing results. Sparse pitch is a really effective solution to the problem. It is the first choice for long cantilever milling, low power machine tools or other applications that must reduce cutting force.
The chip-holding space of ultra-dense toothpitch cutter is very small, and it can be fed by a higher worktable. These tools are suitable for cutting discontinuous cast iron surfaces, roughing of cast iron and small allowances of steel, such as side milling. They are also suitable for applications where low cutting speed must be maintained. Milling cutters can also have uniform or unequal pitches. The latter refers to the unequal spacing of the upper teeth of the cutter, which is also an effective method to solve the vibration problem.
When there is vibration problem, it is recommended to use sparse unequal pitch milling cutter as far as possible. Because there are few blades, the possibility of vibration intensification is small. Small tool diameter can also improve this situation. The combination of groove shape and brand which can be well adapted - sharp cutting edge and good toughness brand combination should be used.