What is roughing in machining? The difference between rough machining and finish machining

Generally, the cutting process is divided into two steps, with different cutting parameters and different results. Roughing is usually the first process followed by finishing. Through all stages, the required CNC products can be made from blanks. This paper mainly discusses the rough machining and the difference between rough machining and finish machining.

What is roughing in machining?

Roughing in machining is mainly used to quickly remove large pieces of material, roughing the workpiece to achieve the desired shape, making follow-up machining more convenient and efficient. The purpose of roughing is to quickly remove the blank allowance, usually choose a larger feed speed and cutting depth, so as to remove as many chips as possible in a short time. Therefore, the rough products are often low precision, rough surface, high production efficiency. Roughing is usually semi-finishing and finishing preparation.

Why roughing in machining? The advantage of the roughing

-roughing operation is that fast feeding can be achieved and the error can be corrected by subsequent finishing, thus ensuring quality.

-Divide the processing stages to make full use of the advantages of the roughing and finishing equipment. Rough machining equipment with high power, high efficiency, strong rigidity, high precision machining equipment, small error.

-Rough machining can find all kinds of defects, such as sand hole, Air Hole, machining allowance is insufficient, easy to repair or scrap, do not waste processing time and cost.

-After hot-working, the residual stress of the workpiece is bigger, the coarse and finish machining are separated, the residual stress can be eliminated by aging, and the deformation can be eliminated by cooling.

-Roughing is performed prior to machining and finishing to protect surfaces at different stages from wear

Roughing and finishing —The difference between rough machining and finish machining

In order to meet the basic requirements of NC machining, it is necessary to carry out a series of operations in the machine shop, including turning, milling, surface machining, etc. .. The traditional process is suitable for high clearance rate and high surface quality, which involves two stages or two processes. Rough machining is used to produce close to the finished geometry in a short time. After rough machining, the final geometry and other details are refined. What's the difference between roughing and finishing?

1. Purpose. Rough machining is mainly to remove a large number of redundant materials, finishing is mainly to improve the Surface finish, tolerance, reduce or minimize errors.

2. Parameters. Rough machining adopts higher feed speed and cutting depth.

3. MMR. The material removal rate of rough machining is higher than that of finish machining.

4. Surface finish. The surface quality after finishing is better than that after roughing.

5. Accuracy. Finish machining or finishing can provide high dimensional accuracy and precision tolerances that roughing can not.

6. Cutting tool. Different roughness requires different blade and cutting angle. Negative rake blades are best suited for roughing because they absorb cutting force and thus increase cutting speed. When finishing, a positive rake blade is usually used to obtain a better Surface finish.