W = Uncoated carbide
C = CVD-coated carbide
P = PVD-coated carbide
T = Uncoated Cermet
E = Coated Cermet
N = Uncoated silicon nitride
M = Coated silicon nitride
S = Mixed ceramic
K = Whisker ceramic
I = Sialon
D = PKD
B = PCBN
L = Coated PCBN
H = PM-HSS
Option 1: Number
1 = Steel
2 = Stainless steel
3 = Cast iron
4 = Alloys and non-ferrous metals/non-metals
5 = Super alloys/titanium
6 = Hard materials
7 = Multi-use grade without particular material focus
Option 2: ISO letter
P = Steel
M = Stainless steel
K = Cast iron
N = Alloys and non-ferrous metals/non-metals
S = Super alloys/titanium
H = Hard materials
X = Multi-use grade without particular material focus
1 = Turning
2 = Milling
3 = Grooving
4 = Drilling
5 = Thread turning
6 = Other/bar peeling/heavy machining
7 = Multi-use grade without particular application focus
e.g. 01, 05, 10, 15, 25, 35 ISO P35
Grade designation "P635" = "CTCP635"