Instructions

THREADS GEAR GEAR GEAR GEAR GEAR GEAR GEAR
PER IN. A B C D E F G
80 50 100 20 40 38 28 22
76 50 100 20 38 40 30 22
72 50 100 20 36 40 28 34
68 50 100 20 34 40 28 30
64 50 100 20 32 40 28 30
60 50 100 20 30 40 28 26
56 50 100 20 28 40 26 30
52 50 100 20 26 40 24 34
48 50 100 20 24 40 26 30
44 50 100 20 22 40 26 30
40 100** 100 20 40 38 28 22
39* 100** 100 20 39 40 28 22
38 100** 100 20 38 40 30 22
37* 100** 100 20 37 40 26 28
36 100** 100 20 36 40 28 34
35* 100** 100 20 35 40 28 26
34 100** 100 20 34 40 28 30
33* 100** 100 20 33 40 28 30
32 100** 100 20 32 40 28 30
31* 100** 100 20 31 40 28 26
30 100** 100 20 30 40 28 26
29* 199** 100 20 29 40 26 30
28 100** 100 20 28 40 26 30
27* 100** 100 20 27 40 26 30
26 100** 100 20 26 40 24 30
25* 100** 100 20 23 40 26 30
24 100** 100 20 24 40 26 30
23* 100** 100 20 23 40 26 30
22 100** 100 20 22 40 26 30
21* 100** 100 20 21 40 26 30
20 100** 100 20 20 40 26 24
19 RH 100** 100 40 38 30 -- --
19 LH
+
100** 50 20 38 -- 30 22
18 RH 100** 100 40 36 30 -- --
18 LH
+
100** 50 20 36 -- 28 34
17 RH 100** 100 40 34 30 -- --
17 LH
+
100** 50 20 34 -- 28 30
16 RH 100** 100 40 32 30 -- --
16 LH
+
100** 50 20 32 -- 28 30
15 RH 100** 100 40 30 32 -- --
15 LH
+
100** 50 20 30 -- 28 26
14 RH 100** 100 40 28 30 -- --
14 LH
+
100** 50 20 28 -- 26 30
13 RH 100** 100 40 26 30 -- --
13 LH
+
100** 50 20 26 -- 24 30
12 RH 100** 100 40 24 30 -- --
12 LH
+
100** 50 20 24 -- 26 30
11 RH 100** 100 40 22 30 -- --
11 LH
+
100** 50 20 22 -- 26 30
10 RH 100** 100 40 20 30 -- --
10 LH
+
100** 50 20 20 -- 26 24
9
+
100** 50 40 36 30 -- --
8
+
100** 50 40 32 30 -- --
7
+
100** 50 40 28 30 -- --
6
+
100** 50 40 24 30 -- --
5
+
100** 50 40 20 30 -- --
PITCH GEAR GEAR GEAR GEAR GEAR GEAR GEAR
(mm) A B C D E F G
.25 50 127** 20 40 30 28 22
.3 50 127** 24 40 30 26 22
.35 50 127** 28 40 30 26 22
.4 50 127** 32 40 30 24 22
.45 50 127** 36 40 30 20 22
.5 100 127** 20 40 30 28 22
.55 100 127** 22 40 30 28 20
.6 100 127** 24 40 30 28 22
.65 100 127** 26 40 30 28 22
.7 100 127** 28 40 30 26 22
.75 100 127** 30 40 28 24 22
.8 100 127** 32 40 30 24 22
.85 100 127** 34 40 30 20 22
.9 100 127** 36 40 30 20 22
1.0 RH 100 127** 20 20 40 -- --
1.0 LH 100 127** 20 20 -- 26 24
1.1 100 127** 22 20 40 24 26
1.2 100 127** 24 20 40 22 26
1.25 100 127** 30 24 38 22 26
1.3 100 127** 26 20 40 22 24
1.4 100 127** 28 20 38 22 24
1.5 100 127** 30 20 38 20 26
1.6 100 127** 32 20 38 20 26
1.7 100 127** 34 20 38 20 22
1.75 100 127** 35* 20 38 20 22
1.8 100 127** 36 20 38 -- --
1.9 100 127** 38 20 36 -- --
2.0 100 127** 40 20 30 -- --
Figure 5—Gear Selection Chart for Thread Cutting Attachment
NOTE—Gear “E” or “F” and
“G” are idler gears and are
used to transmit power and
control direction of rotation
only. See drawings on page
7 for more detail of how
gears are actually installed
on the support arms.
* Gears marked with an asterisk and highlighted in a grey box are not
included in the standard set but can be purchased separately.
**METRIC LATHES—To use this chart with the model 4100 or 4410
(metric) lathe, use a 100-tooth gear in place of the 127-tooth gear ("B" gear)
when cutting metric threads and a 127-tooth gear in place of the 100-tooth
(“A” gear) when cutting inch threads. Press the shaft out of the 127-tooth
gear and into the 100-tooth gear. Inch threads finer than 40 T.P.I. cannot
be cut on the metric lathe.
NOTE—When cutting right hand threads, Gear “E” is used in the vertical
slot of the secondary support arm, part number 3103. When cutting left
hand threads, gear “F” is used in the vertical slot and gear “G” is used in
the horizontal slot and gear “E” is not used.
P/N 3100, Pg. 6 of 8
+
See notes on page 5 for cutting left-hand threads coarser than 20 T.P.I.
and for cutting right-hand threads with a pitch of 5 through 9 T.P.I.
Gears F and G used
for LH threads only
Gear E used for
RH threads only
Gears F and G used
for LH threads only
Gear E used for
RH threads only
NOTE: This chart lists gears used with
the inch version of the lathe. For use
with metric lathes see the note ** below
the chart for alternate gearing.