6.9.7. Mount the workpiece in the lathe with the left hand end of the intended thread as far from the chuck as possible.
6.9.8. With the tool positioned for the first cut, ensure that the automatic feed is engaged (fig.2.B) and that the leadscrew lever (fig.2.A) is
set to I or II as required for the thread.
6.9.9. Ensure that the cross slide lock (fig.1.8) is not applied.
6.9.10. Lower the chuck guard and switch on the lathe.
6.9.11. When the tool reaches the end of the thread switch off the lathe.
DO NOT
disengage the leadscrew.
6.9.12. Reposition the tool for the second cut by moving the forward/reverse switch (fig.2.C) to reverse and starting the lathe. When the tool
clears the start of the thread switch off the lathe.
6.9.13. Adjust the tool for the second cut and move the forward/reverse switch to forward.
6.9.14. Start the lathe for the second cut. Repeat as necessary to complete the thread cutting.
Metric Threads
Thread
Gear Size (Teeth)
Leadscrew
Pitch mm A
B
C
D
Lever
0.5
50
40
49
42
I
0.6
60
40
42
36
I
0.7
56
42
49
32
I
0.75
60
36
42
32
I
0.8
56
32
48
36
I
1.0
60
36
56
32
I
1.0
50
40
49
42
II
1.25
63
32
50
27
I
1.5
63
32
60
27
I
1.5
60
36
42
32
II
1.75
60
36
49
32
II
2.0
60
36
56
32
II
2.5
63
32
50
27
II
3.0
63
32
60
27
II
Auto Feed for Turning
Feed Rate
Gear Size (Teeth)
Leadscrew
mm/rev A
B
C
D
Lever
0.075
30
60
27
63
I
0.15
30
60
27
63
II
Imperial
Threads
Threads
Gear Size (Teeth)
Leadscrew
Per Inch A
B
C
D
Lever
40
50 36
56
42
I
38
50 57
60
27
I
36
50 54
60
27
I
34
60 51
50
27
I
32
60 48
50
27
I
30
56 42
50
27
I
28
60 42
50
27
I
26
60 39
50
27
I
24
60 36
50
27
I
22
60 33
50
27
I
20
50 36
56
42
II
19
50 57
60
27
II
18
50 54
60
27
II
17
60 51
50
27
II
16
60 48
50
27
II
15
56 42
50
27
II
14
60 42
50
27
II
13
60 39
50
27
II
12
60 36
50
27
II
11
60 33
50
27
II
fig.7
fig.8
Spindle
Speed rpm
A 160
B 250
C 400
D 630
E 1000
F 1600
fig.5
fig.4
fig.6
Original Language Version
SM27.V2 Issue: 2(L) - 06/03/15
© Jack Sealey Limited
