Общий каталог Yamawa 2021 - страница 638

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4. Cutting angle and thread relief Intro Cutting angle and Chamfer relief angle θ: Cutting angle γ: Chamfer relief angle Chordal Hook Angle Rake Angle Tangential Hook Angle SP SL PO ST Cutting angle of hook face. Cutting angle of rake face. Cutting angle of hook face. The angle between the center line passing The angle between the center line passing The angle between the center line passing the cutting edge and the straight line linking the cutting edge and the straight line linking the cutting edge and the straight line tan- the cutting edge with the thread root. the cutting edge with thread root. gent to the rake face on the cutting edge. ROLL Thread relief S: Indicator drop for thread relief Concentric-unrelieved Con-eccentric thread relief Eccentric thread relief CARBIDE (A) (B) LONG HAND TAPS EG (STI) No relief exists at land. Start (A) and heel (B) Radial relief in the thread form starts at the Radial relief in the thread form starts at the of thread land have same concentricity. back of a concentric margin. cutting edge and continues to the heel. SPECIAL THREADS, GAUGES Land A The amount of cut portion THREAD Land D Please refer to the pictures shown. For the taps with MILLS 4 flutes and 3 threads chamfer, the cutting operation Land B progresses in order from the edge of A1, B1, C1, D1… Land A A2, B2…A4. Tap end is usually smaller than the size of bored hole, and A1 may not make any cutting operation. DIES Land C Land B t: Amount of cut portion per blade CENTER DRILLS Land C Technical info Land D Tapping direction Bored hole diameter 639 t