All dimensions are in inches and reference unless toleranced.
Insert Length
Insert Thread
L Insert Length
Insert Length Code
2-56
.118
118
.1552
155
4-40
.157
157
.188
188
.2242
224
6-32
.197
197
.2792
279
8-32
.157
157
.188
188
.228
288
.3192
319
10-24 10-32
.228
228
.3732
373
1/4-20 1/4-28
.269
269
.374
374
.4982
498
5/16-18 5/16-24
.4982
498
3/8-16 3/8-24
.4982
498
1/2-13 1/2-20
.6262
626
All dimensions are in inches and reference unless toleranced.
Preferred insert length.
Custom insert lengths available by request.
Stud Length
StudThread
Stud Thread Code
D Insert Diameter
S - Stud Length
.187
.250
.312
.375
.437
.500
.625
.750
.875
1.000
Stud Length Code
2-56
256
.137
187
250
312
-
-
-
-
-
-
-
4-40
440
.174
187
250
312
375
437
-
-
-
-
-
6-32
632
.205
187
250
312
375
437
500
-
-
-
-
8-32
832
.239
187
250
312
375
437
500
625
-
-
-
10-24
1024
.269
187
250
312
375
437
500
625
750
-
-
10-32
1032
.269
187
250
312
375
437
500
625
750
-
-
1/4-20
2520
.333
-
250
312
375
437
500
625
750
875
1000
1/4-28
2528
.333
-
250
312
375
437
500
625
750
875
1000
5/16-18
3118
.394
-
-
312
375
437
500
625
750
875
1000
5/16-24
3124
.394
-
-
312
375
437
500
625
750
875
1000
3/8-16
3716
.485
-
-
-
375
437
500
625
750
875
1000
3/8-24
3724
.485
-
-
-
375
437
500
625
750
875
1000
1/2-13
5013
.643
-
-
-
-
-
500
625
750
875
1000
1/2-20
5020
.643
-
-
-
-
-
500
625
750
875
1000
All dimensions are in inches and reference unless toleranced.
Custom stud lengths available by request.
Boss Design Recommendation
The TWZ Twin Zert is designed to be installed into a straight molded hole with a 0.5° inclusive taper. The top of the hole should not be countersunk or counterbored as this will decrease the insert’s performance. The recommended hole size applies at the point reached by the bottom of the insert. Molded holes should be used wherever possible as drilled holes may result in diminished performance. Minimum boss wall thicknesses shown are for reference and may vary depending on the type of plastic.
Installation
Pre-heating is the recommended installation method. The insert should be hot enough to soften the plastic without melting it to avoid flash around the top. Avoid excessive pressure that would force an insert into a hole without allowing the plastic to properly soften and flow around the insert features.