PEM®

Self-clinching fasteners

Thread support for thin sheets: firm, durable and economical installation

The idea

to develop an easily installable self-clinching fastener that can be used to provide a high load-bearing thread in thin sheets, printed circuit boards and plastic parts was initiated by PEM® way back in 1942. These new types of fastener save time, weight and the number of components. The technology of self-clinching fasteners became accepted during the economic revival in the fifties and the product range has grown due to the reduction of the thickness of sheet materials. The original parts were modified over the years and nowadays they are appropriate for a wide range of applications.

Advantages of self-clinching fasteners

• Provide high load-bearing threads in thin sheets from 0.5 mm onwards
• Can be installed using any parallel installation method
• Have high torque-out and pull-through values
• Do not require special processing of the bore like countersinking or deburring
• Back side of the sheet is not damaged, no bulging
• Threads need not be cut again
• Lesser installation costs
• Can also be mounted on coated surfaces
• High accuracy in positioning
• Exact rectangularity with respect to the sheet

Why, how and where self-clinching fasteners are used

A PEM® fastener is simply a part, mostly having threads, which when installed in a fluid material, removes the material in the hole in such a manner that it flows in a special undercut in the shank area due to cold-forming. Twisting is prevented with the help of knurls or a special shape of the head. The fastener thus forms a unit along with the work piece in which it was installed. PEM® fasteners are mainly used when high torque-out and pull-through values are required in thin materials since this cannot be ensured by other methods. Use of these fasteners may prove to be economical in sheets where threads could be provided. Thinner sheets can be used to save costs in the entire assembly. PEM® products have been accepted in diverse areas long ago: from aviation and space industry to mechanical engineering, telecommunications, general instrumentation, office equipment, electronics and automobile design and where firm and durable anchoring is required in thin-walled sheets, printed circuit boards or plastic parts.

Installation:

1. Drill a hole

2. Insert PEM®

3. Press

4. Screw

Installation instructions

• Determine the hole sizes from the relevant data sheets
• Do not deburr or countersink mounting holes
• Fastener should be installed in purchside of hole
• Install PEM® parts (do not drive in parts with a hammer)
• Maintain minimum edge distances (avoid deformation near the edges of a sheet)
• Install PEM® parts made of steel or stainless steel only after anodizing while using them in aluminium

Technical specifications

• Thread tolerance: nuts 6H, studs 6g/4h
• Also available with UNC/UNF threads on demand
• Surface protection: zinc-plated steel parts, plating thickness of 5-6 µ, stainless steel = passivated
• Other finishes can be provided
• All dimensions in mm