The machinability of steel differs, depending on alloying elements, heat treatment and manufacturing process (forged, cast, etc.)
- In soft, low carbon steels, built-up edge and burr formation on the workpiece are the main issues.
- In harder steels, the positioning of the cutter becomes more important to avoid edge chipping.
Suitable cutters and inserts
- Most CoroMill cutters are well suited for steel machining with a comprehensive assortment of insert grades and geometries.
- Note that CoroMill Century (with steel body) and CoroMill 790, originally developed for aluminum, also perform very well in finishing steel.
- The only tools not suitable for steel are the AUTO-cutters dedicated for gray cast iron.
- PL, PM, PH and WL, WM, WH geometries
- The GC4200-series of MT-CVD coated grades are the basic choice. However, for smaller diameter cutters, below Dc 1.260 inch (32 mm), and for shoulder milling cutters, ψr=0°, grade GC1030 is the first choice.
- In harder steels, use GC1030 and GC1010.
Cutting speed and grade recommendations related to material hardness.
Recommendations, such as positioning of the cutter to avoid a large chip thickness on the exit, and to always run dry without cutting fluid, should always be considered, especially in roughing operations.
Grade guideline – face milling
Grade guideline – end milling CoroMill® 490, CoroMill® 390, CoroMill® 316