BB Unequal Helix Carbide End Mill | JIN / BK40-SUS / BK40-UM | Dynamic & Trochoidal Milling

BB Unequal Helix Carbide End Mill Series

Engineered for high-performance dynamic milling, trochoidal machining, and side milling. All three series feature an unequal helix angle design that actively dampens vibration, improves surface finish, and extends tool life.

🔶 JIN Series (BB-JIN)

• Geometry: 38° + 40° unequal helix angle (8° differential), asymmetric design
• Coating: TiZr (Titanium Zirconium) — excellent heat resistance and lubricity
• Substrate: High hardness and high toughness carbide
• Applications: Stainless steel, titanium alloy, heat-resisting alloy, superalloy, mild steel, brass, copper, non-ferrous metals
• Material grades: A3, 45#, 40Cr, 20Cr, 304, 316L, TC4, TC6, 4J29
• Machining strategies: Side milling, dynamic milling, trochoidal machining, layer milling

🔷 BK40-SUS Series

• Geometry: 38° primary helix + 41° secondary helix — optimized for vibration damping
• Rake angle: High positive radial rake for free-cutting action
• Clearance angle: Optimized for maximum tool life
• Substrate: High hardness and high toughness carbide
• Applications: Stainless steel, titanium alloy, heat-resisting alloy, superalloy, mild steel, brass, copper, non-ferrous metals
• Material grades: A3, 45#, 304, 316L, TC4, TC6
• Machining strategies: Side milling, dynamic milling, trochoidal machining

⬛ BK40-UM Series (Ultra-Hard Materials)

• Geometry: Unequal helix angle — vibration suppression for hard material cutting
• Applications: Oxygen-cut parts, welded components, die steel, tool steel, heat-treated high-hardness stainless steel
• Material grades: SKD11, 718H, P20, Cr12, 430, 630
• Hardness range: HRC 50–63
• Machining strategies: Side milling, dynamic milling, trochoidal machining, layer milling

📋 Usage Recommendations

1. Before use, measure tool runout. If runout exceeds 0.01 mm, correct before cutting.
2. Minimize tool overhang from the chuck. Longer overhang requires reduced speed, feed, and depth of cut.
3. If abnormal vibration or noise occurs, reduce spindle speed and cutting parameters until stable.
4. Use spray or mist coolant for steel cutting to maximize tool life.
5. Not suitable for low-speed machines such as bench drills or hand drills.