ISO P-Steel is the largest materialgroup in the metal cutting area, rangingfrom unalloyed to high-alloyed materialincluding steel castings and ferritic andmartensitic stainless steels. Themachinability is normally good, but differsa lot depending on material hardnesscarbon content, etc.

ISO M-Stainless steels are materialsalloyed with a minimum of 12%chromium; other alloys are, e.g.. nicke!and molybdenum. Different conditionssuch as ferritic, martensitic, austeniticand austenitic-ferritic (duplex), makes thisan extensive material group. Common forall these types are that they exposecutting edges to a great deal of heat,notch wear and built-up edge.

ISO K-Cast iron is, contrary to steel, ashort-chipping type of material. Gray castiron (GCl) and malleable cast irons (MCl)are quite easy to machine, while nodularcast iron (NCl),compacted graphite iron(CGl) and austempered cast iron (ADl) aremore difficult. All cast irons contain siliconcarbide (SiC) which is very abrasive to thecutting edge.

ISO N-Non-ferrous metals are softertypes of metals such as aluminum,copper, brass, etc. Aluminum with asilicon content (Si) of 13% is very abra-sive. Generally high cutting speeds andlong tool life can be expected forinsertswith sharp edges.

ISO S-Heat Resistant Super Alloysinclude a great number of high-alloyediron, nickel, cobalt and titanium-basedmaterials. They are sticky create built-upedge, workharden and generate heat,very similar to the lSO M-area, but theyare much more difficult to cut, leading toshorter tool life for the cutting edges.

ISO H-This group covers steels with ahardness between 45-65 HRc and alsochilled cast iron around 400-600 HBThe hardness makes them all difficult tomachine. The materials generate heatduring cutting and are very abrasive tothe cutting edge.