
Technical Information for Thread Milling Technical Information for Thread Milling
Tool Selection
For indexable and solid carbide Mill Threads
The following chart provides a fairly accurate visual selection tool for Internal Threading.
The chart is suitable for the following thread forms : ISO, UN, WHIT, NPT, NPTF, BSPT and PG .
Conversion of Cutting Speed to P=Thread Pitch
A
Rotational Speed TPI mm
D= Tool cutting diameter
1
4 6.0
Conversion of selected cutting speed to rotational
N
speed is calculated by the following formula: 5 5.0
Example: v=120 m/min
D=30 mm 6 4.0
N=
Vx 1000
JT x D
120 x 1000
3.14 x 30
=1274 RPM
V
V D
D=Cutting diameter 8
3.5
3.0
m 00
D=21 D=29
10 2.5 1 10 O Q o
12 2.0 0 " 8
16 1.5
Internal Thread External Thread
u
20 1.25
24 1.0 D=9 D=12
32 0.75
3
48 0.5 090
Left Hand Right Hand Left Hand
Thread Thread Thread mm 4 5 6 7 8 9 10 11 12 13 14 15 16 18 20 22 24 26 28 30 32 34 36 38 40 44 48 52 58 64
§
¥
inch 1/4 3/8 1/2 5/8 3/ 4 1 1.25 1.5 2 2.5
*
8