TM 1-1500-204-23-6
Table 2-16. Twinsert and Tools Data
Nominal
Screw thread
Screw lock
Length
Finish
Insert
Tang
thread
twinsert
twinsert
tap
tool
break-off
Extract
size
assy No.1
assy No.1
1 1/2 Dia.
2 Dia.
part No.
part No.
tool No.
tool No.
National Coarse Series
4-40
3180-04CN
3182-04CN
.168
.224
3887-04
2698-04
3580-2
1227-06
5-40
3180-05CN
3182-05CN
.188
.250
3887-05
2698-05
1194-2
1227-06
6-32
3180-06CN
3182-06CN
.207
.276
3887-06
2698-06
1195-3
1227-06
8-32
3180-2CN
3182-2CN
.246
.328
3887-2
2698-2
1195-1
1227-06
10-24
3180-3CN
3182-3CN
.285
.380
3887-3
2698-3
1195-4
1227-6
12-24
3180-1CN
3182-1CN
.324
.432
3887-1
2698-1
1196-4
1227-6
1/4-20
3180-4CN
3182-4CN
.375
.500
3987-4
2698-4
1195-5
1227-6
5/16-18
3180-5CN
3182-5CN
.469
.625
3987-5
2698-5
1195-6
1227-6
3/8-16
3180-6CN
3182-6CN
.562
.750
3987-6
2698-6
1195-7
1227-16
7/16-14
3180-7CN
3182-7CN
.656
.875
4087-7
2698-7
1196-8
1227-16
1/2-13
3180-8CN
3182-8CN
.750
1 000
4087-8
3724-10
1196-9
1227-16
National Fine Series
6-40
3181-06CN
3183-06CN
.207
.276
3893-06
2705-06
3581-3
1227-06
10-32
3181-3CN
3183-3CN
.285
.380
3893-3
2705-3
1195-4
1227-6
1/4-28
3181-4CN
3183-4CN
.375
.500
3893-4
2705-4
1195-5
1227-6
5/16-24
3181-5CN
3183-5CN
.469
.625
3893-5
2705-5
1195-6
1227-6
3/8-24
3181-6CN
3183-6CN
.562
.750
3993-6
2705-6
1196-7
1227-16
7/16-20
3181-7CN
3183-7CN
.656
.875
3993-7
2705-7
1196-8
1227-16
1/2-20
3181-8CN
3183-8CN
.750
1.000
3993-8
2705-8
1196-9
1227-16
Drill
Tap
Nominal
minor Dia.
Assembled
thread
after tap
Major Dia.
Pitch Dia.
pitch Dia.
size
min-max
min
min-max
min - max
National Coarse Series
4-40
.150-
.156
.1737
.1608-
.1625
.1283-
.1308
5-40
.163-
.169
.1867
.1738-
.1755
.1413-
.1438
6-32
.186 -
.193
.2148
.1989 -
.2008
.1583 -
.1611
8-32
.212-
.219
.2408
.2249-
.2269
.1843-
.1872
10-24
.254-
.261
.2920
.2711-
.2734
.2170-
.2203
12-24
.280-
.287
.3181
.2971-
.2995
.2430-
.2464
1/4-20
.326-
.334
.2723
.3474-
.3502
.2825-
.2863
5/16-18
.395-
.403
.4485
.4207-
.4240
.3486-
.3529
3/8-16
.467-
.475
.5281
.4968-
.5005
.4156-
.4203
7/16-14
.547-
.559
.6122
.5767-
.5808
.4839-
.4890
1/2-13
.617-
.629
.6882
.6498-
.6543
.5499-
.5554
See footnote at end of table.
2-64
