High-Performance Solid Carbide End Mills • Hard Materials
Table of Factors to Maximise Ball Nose Cutting Speed for Hard Machining • Metric
Calculation Examples
Table of Factors for Speed Calculation of Ball Nose
ap/D
Average Wall
Angle 0.003 0.006 0.010 0.016 0.020 0.025 0.030
0.0° 9.1 6.5 5.0 4.0 3.6 3.2 2.9
3.0° 6.2 4.9 4.0 3.3 3.0 2.8 2.6
5.0° 5.1 4.2 3.5 3.0 2.8 2.5 2.4
8.0° 4.1 3.4 3.0 2.6 2.4 2.3 2.1
10.0° 3.6 3.1 2.7 2.4 2.3 2.1 2.0
15.0° 2.8 2.5 2.2 2.0 1.9 1.8 1.7
20.0° 2.3 2.1 1.9 1.8 1.7 1.6 1.6
30.0° 1.7 1.6 1.5 1.4 1.4 1.3 1.3
40.0° 1.4 1.3 1.3 1.2 1.2 1.2 1.2
50.0° 1.2 1.2 1.1 1.1 1.1 1.1 1.1
55.0° 1.1 1.1 1.1 1.1 1.1 1.0 1.0
For calculating real cutting speed, use formula: Basic cutting
speed * Factor
Example 2:
For Tool = 8mm and ap = 0,1mm for average wall angle 10°, ap/D ratio
equal 0,1/8 = 0,0125. Factor will be between 2.7 and 2.4, choose 2.6.
Material
Group min P3 160 – 180
P4 140 – 160
H1 100 – 140
max
H2 70 – 120
Keep in mind shank diameter and length effect. H3 60 – 90
If tool length out of the chuck is more than 2 x D, please decrease feed
per tooth by 15% each 1 x D. H4 50 – 70
Application example #1 =
face milling a flat surface Application example #2 =
face milling a 10° average wall angle
D = 10mm D = 8mm
ap = 0,2mm ap = 0,1mm
Average wall angle = 0° Average wall angle = 10°
Finishing H2 Finishing H2
Starting vc from chart = 100 Starting vc from chart = 100
ap/D = 0.02 ap/D = 0,1/8 = 0,0125
Factor from table =
3.6 Factor from table =
2.6
vc to programme into machine = 100 * 3.6 = 360 m/min vc to programme into machine = 100 * 2.6 = 260 m/min
RPM = 360* 1000/3.14/10 = 11460 RPM RPM = 260* 1000/3.14/10 = 7640 RPM
widia.com
Example 1:
For Tool = 10mm and ap = 0,2mm for average wall angle 0°, ap/D ratio
equal 0,2/10 = 0,02. Factor equal 3.6.
O205
Choose the coefficient according to the ap/D and average wall angle.
TiAlN or AlTiN
Basic Cutting Speed Vc
m/min