The rough turning "eats deep cuts" and the finish turning "eats thin layers", balancing efficiency and precision

Cutting depth (back draft) refers to the cutting depth of the tool into the workpiece, which directly determines the metal cutting efficiency, tool load and part surface quality. The cutting depth settings of rough turning and fine turning are very different, and the core is "rough turning weight efficiency and fine turning weight accuracy".

Cutting depth of rough turning: with "maximize the removal allowance and reduce the number of tool passes" as the core, on the premise that the machine power, tool strength and process system rigidity allow, the cutting depth shall be increased as much as possible to shorten the machining time. The reference range is as follows:

Ordinary CNC lathe machining 45 # steel: single-side cutting depth can be set as 2-5mm, and the maximum single-side cutting depth of medium power machine tool can reach 8-10mm;

Hard to machine materials (such as titanium alloy and stainless steel): the single-side cutting depth shall be controlled within 0.5-2mm to avoid too fast wearing or chipping of cutters;

Castings/Forgings: The first tool is to be 2-3mm deep, quickly removing surface scale and hard layers, and then gradually reducing the cutting depth.

Finishing cutting depth: taking "ensuring surface roughness and reducing tool wear" as the core, small cutting depth is adopted to ensure stable cutting and avoid vibration and tool marks. The reference range is as follows:

Conventional finish turning: the single-side cutting depth is 0.1-0.5mm, which can be reduced to 0.1-0.3mm if the surface roughness is required to be high (Ra ≤ 0.8 μ m);

Precision finishing: the single-side cutting depth is controlled at 0.05-0.2mm, and the high-speed cutting is matched to improve the surface smoothness;

Fine turning of thin-wall parts: the single-side cutting depth shall be controlled within 0.05-0.15mm to avoid deformation of workpieces and affect the dimensional accuracy.

Practical operation skills of Richeng: the cutting depth needs to be matched with feed and cutting speed in a coordinated manner - in rough turning, large cutting depth is matched with large feed (0.3-0.8mm/r) and low cutting speed (50-100mm/min) to improve efficiency; During finishing, small cutting depth, small feed (0.05-0.2mm/r) and high cutting speed (100-200mm/min) guarantee quality. At the same time, we will optimize the cutting depth according to the tool material. For example, the cutting depth of carbide tools can be appropriately increased, and ceramic tools are suitable for high-speed small cutting depth machining.