Plastic Enclosure Functional Features

Bosses and Inserts:

• Self tap or brass insert – Less than 2-3 insertions use self tap – 4 mm minimum for self tap depth• Try to keep shorter than 9mm – Otherwise use sidewall tabs – Frames• Combine bosses to save $$• Through-wall brass inserts OK – 4-40 height is .093” – 6-32 short is .125”• Studs tend to fall out prior to fastening• Male/female hex stack-up require brass inserts• Can also use Rivnuts 

Access Doors:

• Slide-in, no fasteners – Requires frame or undercut – Difficult to create good snap• Otherwise use fastener with brass insert and frame 

Pockets & recesses:

• Machined or through with insert from back – Insert is best way to eliminate machine marks, less expensive for pockets larger than approximately 9 square inches• For cosmetic purposes – Labels, nameplates, decals & overlays – Use thicker (.015”) material to hide machine marks• For keypads – May require stiffener; may be less expensive to insert – .010” clearance per side• For rubber feet – Non-skid, feet won’t slip around on plastic over time 

Cooling – Fans & Vents:

• Vents – Machined vent pattern has great flexibility – Holes more expensive than slots – 2mm minimum slot width – If too long, leave in cross supports• Fans – Mount with through holes or bosses – Self taps or brass inserts – Open vent pattern, keep as open as possible to reduce back pressure – Match area of inlet and outlet – Rule of thumb, cool air blows over the fan motor 


• Usually acrylic, solvent bonded into recess from rear• Bezel approach OK for polycarbonate (FR rated)• Acrylic/HIPS bond well• Acrylic/ABS moderate bond• Polycarbonate does not solvent bond• Windows can be flush to front or recessed with chamfer 

Cosmetics & Decorating:

• Decorating – Silkscreening – Paint – can fill seams inconsistently – Decals, nameplates• 2-color inserts – Same installation as windows 

Hinges and Handles:

– Standard hardware usually most economical• Belt clips• DIN clips• Handles• Latches• Acrylic hinges (solvent bonded in place – optimized for Tool-Less process)• Metal hinges• Key locks