Materials for cutting tools. Numerical data in drilling

The first step to be taken by the machinist is to check the tool's qualification with regard to the material and the machining case. All the following numerical data apply to qualified tools.

These data are available for the main materials used by machinists. There are many other materials for which cutting parameters are available.

Materials on offer include non-alloyed multi-R_m steels, low-alloyed multi-R_m steels, ferritic, martensitic and austenitic stainless steels, GG and GGG cast irons, 2000, 6000 and 7000 series aluminum alloys, Inconel 718 nickel-based refractory alloys, grade 5 titanium alloys (TiAl6V).

For drilling technology, and more specifically for drilling with carbide monoblock drills, we differentiate between so-called standard drills and micro drills (diameters less than or equal to 3 mm). In fact, these two families of drills have their own specific characteristics, making it impossible to draw a behavioural law for diameters from 0.2 to 20 mm.

For one-piece drills, cutting parameters are arranged according to the tool's length/diameter (L/D) ratio.

The cutting parameters shown in the following tables for drilling are basic data. Unfortunately, they can vary considerably from one manufacturer to another, depending on the type of drill sharpening, especially for solid carbide twist drills. In the case of insert drills, these are also average values, as each manufacturer decides to change insert sizes to specific diameters.