MTM-202-0.8

2-flute toroid (corner-radius) end mills for hardened steels — the best tool for helical bores and tight corners in die/mold work.

• 2 flute Tuffy grade toroid end mill with corner radius, 30° helix, AlTiN coated — rated for steels at 40, 50, and 64 HRc
• The guide's pick as the best tool for helical bores or tight corners — for large open areas use the HM/MHM Series
• Corner radii scale with diameter: .008 on 1/32", .012 on 1/16", .020 on 3/32"–1/8", .040 on 3/16"–5/16", .080 on 3/8"–7/16", .120 on 1/2" (metric 0.2–3 mm)
• Same three tip styles as the DM line — Style A (8° blend, short tip), Style B (drafted reach neck, draft angles 1°–3°, blend angles 16°–18°, reaches to 1-9/16" / 45 mm), Style C (cutting dia = shank dia, 1/4"–1/2" and 6–12 mm)
• Applications: side milling, helical interpolation, conventional and ramping high-performance roughing, semi-finishing, and finishing — dry, cold air, or spray mist; air or mist coolant above 40 HRc
• Profiling guidance: 1 × diameter axial depth with radial width 5% of diameter at 30–50 HRc and 2% at 50–60 HRc; facing/floor finishing at 2% of diameter axial and 25% radial
• Published semi-finishing/finishing speeds & feeds per tool: e.g. TM-201-08 (1/4") runs 9,000–10,400 RPM at 0.0015–0.002 CLPT in 30–40 HRc, and 4,000–6,600 RPM at 0.0012–0.0016 in 50–60 HRc
• Use climb milling for better finish and longer tool life; engage by helical interpolation or entering from off the part
• Special draft angles (blend angle) or necked shanks for part clearance available on request — usually ship the next business day
• Tolerances: cutting dia −.001/−.002, shank −.0001/−.0002 (MTM: cutting dia −.025/−.050 mm)

From the RobbJack Applications Guide.