Общий каталог Yamawa 2022 - 2023 - страница 1155

Edge angle and Cutting allowance of taps Recommended Tapping Speeds

■Cutting angle and Chamfer relief angle

θ : Cutting angle γ : Chamfer relief angle

Chordal Hook Angle Rake Angle Tangential Hook Angle

■Tapping Speeds

Following usage conditions affect tapping speeds : kind of taps, workpieces, number of chamfered threads, materials, hole condition and fluid. It is necessary to select the suitable tapping speed by paying attention to these conditions. When work material has excellent workability, when there is a little depth of tapping, or when tapping fluid can be sufficient, select rather higher tapping speed. When workability of work material is unknown, to be safe, try nearly the lowest tapping speed at first, and then increase the speed gradually. * Following speed is basically for the cutting condition under the use of insoluble cutting oil. Under the use of water soluble cutting oil, please choose 30% slower speed. Unit : m/min

center line passing the cutting edge and the straight center line passing the cutting edge and the straight center line passing the cutting edge and the straight

■Thread relief

S : Indicator drop for thread relief

Concentric-unrelieved Con-eccentric thread relief Eccentric thread relief

thread land have same concentricity. a concentric margin. edge and continues to the heel.

Please refer to the pictures shown. In such taps as have 4 flutes and 3 thread chamfer, the Land D

cutting operation progresses in order from the edge of

A1, B1, C1, D1…A2, B2…A4. Tap end is usually smaller

than the size of bored hole, and A1 may not make any Land A cutting operation.

Land B

Land A

Land B ■Formula

Tapping Speed (Vc) Revolution Speed of tap (n)

Land C t : Amount of cut portion per blade

Land C

Land D

Tapping direction

Bored hole diameter

n : Revolution Speed of tap (min-1) Vc : Tapping Speed (m/min) : 3.14 Dc : Nominal dia. of tap (mm) Dc : Nominal dia. of tap (mm) : 3.14 Technical Inf