MNS-401-08

4-flute variable-helix Tuffy grade end mills for cast iron and steels to 40 HRc — stub, standard, and long lengths, AlTiN coated, with optional flats for high-torque cuts.

• 4 flute, variable helix — the variable pitch damps harmonics for stable cuts in cast iron and steel up to 40 HRc hardness
• Three lengths per diameter: NS-401 stub, NS-402 standard, NS-403 long (e.g. 1/2": 3/4", 1-1/8", and 1-1/2" flute lengths)
• Inch sizes 3/16"–1"; metric MNS line runs 4–20 mm
• Every tool AlTiN (aluminum titanium nitride) coated, in flats (-FL) and no-flats versions — 'Slippage? Tool Holder — Add Flats!' for high-torque cuts
• Protective corner chamfer on every size, .008 to .02 by diameter (metric 0.2–0.5 mm)
• Guide engagement guidance: slot at 1 × diameter width and .5 × diameter depth; profile at .5 × diameter radial width and 1 × diameter axial depth
• Applications: slotting, side milling, helical interpolation, ramping, high-performance roughing, semi-finishing, and finishing — dry or wet
• Tolerances: NS cutting dia −.001/−.002, shank −.0001/−.0002, flute length +.060/−.000; MNS cutting dia −0.025/−0.050 mm, shank −0.002/−0.005 mm

From the RobbJack Applications Guide.