TWZ Twin Inserts Inch


  • Self–aligning installation using heat.
  • Opposing helical knurls and knurled vanes provide superior pull–out and torque–out resistance.
  • Double–ended to assist automatic feeding by eliminating the need for orientation during installation.
  • Thin boss walls permit compact design.
  • Available in a wide variety of thread sizes, stud lengths and options.
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Loading Parts

Insert ThreadInsert Thread CodeBossD Insert DiameterP Pilot Diameter
B Hole Dia. +0.10 -0.00W Wall Thickness Min.
M2 x 0.4M23.201.303.503.10
M2.5 x 0.45M2.54.001.604.403.90
M3 x 0.5M34.001.604.403.90
M3.5 x 0.6M3.54.801.805.204.70
M4 x 0.7M45.602.106.105.50
M5 x 0.8M56.402.606.806.30
M6 x 1.0M68.003.308.507.90
M8 x 1.25M89.604.5010.009.50
M10 x 1.5M1011.906.0012.3011.80
M12 x 1.75M1216.008.0016.3015.80
Insert Length
Insert ThreadL Insert LengthInsert Length Code
M2 x
M2.5 x 0.454.004.00
M3 x
M3.5 x
M4 x
M5 x 0.85.805.80
M6 x 1.06.806.80
M8 x 1.2512.65212.65
M10 x 1.512.65212.65
M12 x 1.7515.88215.88
  1. All dimensions are in millimeters and reference unless toleranced.
  2. Preferred insert length.
  3. Custom insert lengths available by request.
Stud Thread
Stud ThreadStud Thread CodeD Insert DiameterS – Stud Length
Stud Length Code
M2 x 0.4M23.505.006.008.00
M2.5 x 0.45M2.54.405.006.008.0010.00
M3 x 0.5M34.405.006.008.0010.0012.00
M3.5 x 0.6M3.
M4 x 0.7M46.
M5 x 0.8M56.805.006.008.0010.0012.0014.0016.0018.0020.00
M6 x 1.0M68.506.008.0010.0012.0014.0016.0018.0020.0025.00
M8 x 1.25M810.008.0010.0012.0014.0016.0018.0020.0025.00
M10 x 1.5M1012.3010.0012.0014.0016.0018.0020.0025.00
M12 x 1.75M1216.3012.0014.0016.0018.0020.0025.00
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.

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.