Formulae and machining examples for bar peeling

Formulae for bar peeling

Cutting speed (m/min)

Peeling head speed (rpm)

Feed (mm/rev)

Feed rate (m/min)

Chip volume (cm3/min)

Example calculation:

Indexable insert: YNUF 271220S50-M50 CTCP625
Bar diameter: Ø 77 mm
Cutting depth (ap): 1 mm
Feed (f): 22 (mm/rev)
Selected cutting speed (Vc): 160 (m/min)

Calculation of speed:

Calculation of feed rate:

Calculation of chip volume

Conversion inches ↔ metric

1 inch = 2.54 cm = 0.0254 m
1 foot = 12 inches = 30.48 cm = 0.3048 m
1 metre = approx. 39.37 inches = approx. 3.2808 feet

Machining examples for bar peeling

Finishing in the SINGLE system

Depth of cut ap = 1.2 mm
Bar diameter = 28 mm h9
Material: Cf 53 m.no. 1.1213

Specific cutting force:
Kc1.1 = 1525 N/mm2

Indexable insert:
YNUF 241020-M50

f = 16 (mm/rev)
vc = 135 (m/min)
→ P = 23 kW

Medium machining in the SINGLE system

Depth of cut ap = 3 mm
Bar diameter = 70 mm
Material: X 20 CrNi 17-2 m.no. 1.4057

Specific cutting force:
Kc1.1 = 1875 N/mm2

Indexable insert:
WNEU 161425-R50

f = 12 (mm/rev)
vc = 100 (m/min)
→ P = 42 kW

Roughing and medium machining in the TANDEM system

Depth of cut ap = 3.5 + 1.5 = 5 mm
Bar diameter = 220 mm
Material: X6 CrNiMoTi 17-12-2 m.no. 1.4571

Specific cutting force:
Kc1.1 = 2150 N/mm2

Indexable insert:
RNMH 5018MO + YNUF 201220-M50

f = 14 (mm/rev)
vc = 60 (m/min)
→ P = 54 kW

The calculated power only applies for one tool holder. In the case of a peeling head with 4 tool holders, 4 times the power must be taken into account.

Calculation of the average chip thickness hm

For type L, N, T, W, Y indexable inserts

For type R indexable inserts