Общий каталог Yamawa 2022 - 2023 - страница 1154

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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

Cutting angle of hook face. The angle between theCutting angle of rake face. The angle between theCutting angle of hook face. The angle between the
center line passing the cutting edge and the straightcenter line passing the cutting edge and the straightcenter line passing the cutting edge and the straight
line linking the cutting edge with the thread root.line linking the cutting edge with thread root.line tangent to the rake face on the cutting edge.

■Thread relief

S : Indicator drop for thread relief

Concentric-unrelieved Con-eccentric thread relief Eccentric thread relief

No relief exists at land. Start (A) and heel (B) ofRadial relief in the thread form starts at the back ofRadial relief in the thread form starts at the cutting
thread land have same concentricity.a concentric margin.edge and continues to the heel.

■The amount of cut portion

Land A 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 Land B than the size of bored hole, and A1 may not make any Land A cutting operation. Land C Land B t : Amount of cut portion per blade

■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 Tapping Speed Workpiece Materials

Spiral Fluted Spiral Pointed Roll Taps Straight Fluted Cemented Carbide

Low Carbon Steels Medium Carbon Steels High Carbon Steels Alloy Steels

Thermal refined steels Stainless Steels Tool Steels Cast Steels Cast Irons Ductile Cast Irons Coppers Brass · Brass Casting Phosphor Bronze · Phosphor Bronze Casting Wrought Aluminum Aluminum Alloy Castings Magnesium Alloy Castings Zinc Alloy Diecastings Thermosetting Plastic Bakelite (Phenol-PF) Thermoplastic resin PVC, Nylon Titanium Alloys Ti-6AI-4V etc Nickel Base Alloys Hastelloy, Inconel, Waspaloy

■Formula

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

Land C

Technical Inf 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