Heat-Lok
PSM Heat-Lok is a special insert designed primarily for thermoplastic applications where you want low stress insertion, strong torque and pull-out performance, and high alignment reliability. It is a double-ended, self-aligning brass insert that is installed using heat (rather than ultrasonics), making it ideal for amorphous plastics and precision applications.
Advantages
- Low stress generating characteristics - ideal for amorphous thermoplastics
- Double ended - assists automatic feeding
- High torque resistance
- Self-aligning - assists installation
Heat-Lok Selection of Inserts
Key Features & Strengths
Low stress generation: Heat-Lok is designed to minimize radial or bursting stresses inside the plastic boss, which is especially important for amorphous thermoplastics.
Double-ended design: This assists automatic feeding in high-speed production and allows insertion from either side.
High torque resistance: The insert maintains strong thread engagement against twisting or loosening under load.
Self-aligning during installation: Its geometry helps center it in the hole as it heats and inserts.
Available in both insert and stud forms, and with headed variants, giving flexibility in mounting and design.
ISO Metric
Unified
Other materials and lenghts possible on quotation.
Specifying an Insert & Stud
Boss Design Specification
Hole Preparation
Moulded holes are recommended wherever possible. The taper on a moulded hole should be 0.5° inclusive and the hole diameter recommended should apply at the point reached by the bottom of the insert. The top of the hole should not be chamfered or counterbored and care must be taken to avoid bell mouthing. Hole diameter tolerance:-0.00 +0.10mm.
Moulding Practice
Mould design should be arranged to eliminate residual stresses in the area of the boss or hole into which the insert is to be installed.
Installation
Heat-lok has been designed for installation using heat rather than ultrasonics, since direct heat best suits the plastic flow required by the insert profile.
Wall Thickness
A general guide to minimum wall thickness is given in the data table but this will vary depending upon the nature of the plastic. Where thinner walls are required these can often be accommodated, but consultation with the PSM Technology Centre or local sales office and pre-production testing is strongly advised.
Performance Data
The complexity of materials and variations in service conditions make it impossible to detail fastener performance for specific applications. The chart below gives a general guide and show the relative performance of the inserts in the range.