{"$schema":"nativecad-dfm-pack/1","id":"consumer","title":"Consumer products — housings, enclosures, handheld devices","sector":"consumer","version":"2026-09-03","summary":"Nominal wall by material, draft, ribs, bosses, snap fits, living hinges, ultrasonic welds, gaskets, textures, clamshell joints, battery doors, buttons, and the drop/tumble/cycle tests and standards a plastic consumer housing is held to.","aliases":["consumer product","housing","enclosure shell","clamshell","snap fit","living hinge","remote control","handheld","gadget","case","injection moulded housing","3d printed case"],"crossSector":false,"size":"core","sources":[{"id":"bayer-snap-fit","title":"Bayer/Covestro Snap-Fit Joints for Plastics — A Design Guide","accessed":"2026-09-03"},{"id":"dupont-living-hinge","title":"DuPont Engineering Polymers — Living Hinge Design Guide","accessed":"2026-09-03"},{"id":"protolabs-guide","title":"Protolabs Injection Molding Design Guide","url":"https://www.protolabs.com/resources/design-tips/","accessed":"2026-09-03"},{"id":"fictiv-guide","title":"Fictiv Injection Molding Design Guidelines","url":"https://www.fictiv.com/articles/injection-molding-design-guidelines","accessed":"2026-09-03"},{"id":"hubs-3dp-guide","title":"Hubs (Protolabs) 3D Printing Design Guidelines — FDM/SLS/SLA","url":"https://www.hubs.com/knowledge-base/","accessed":"2026-09-03"},{"id":"iec-60086","title":"IEC 60086 Primary Batteries — cell dimensions (AA, AAA, coin cells)","url":"https://webstore.iec.ch/publication/3049","accessed":"2026-09-03"}],"entries":[{"id":"wall-thickness-abs","kind":"dimension","tier":1,"title":"Nominal wall thickness, ABS injection moulding","summary":"ABS consumer housings run a 1.5-3.5 mm nominal wall, 2-2.5 mm typical; thinner short-shots the cavity, thicker sinks and slows cycle time.","applies":["abs","injection molding","housing"],"value":{"min":1.5,"max":3.5,"typical":2.5,"unit":"mm"},"basis":"Standard ABS moulding wall-thickness guidance for enclosure-class parts","sources":["protolabs-guide"],"tags":["wall","abs","injection-molding"],"check":{"process":"injection_molding","rule":"min_wall_thickness"}},{"id":"wall-thickness-pc","kind":"dimension","tier":1,"title":"Nominal wall thickness, polycarbonate (PC) injection moulding","summary":"PC housings run a 1.5-3.0 mm nominal wall; PC's higher viscosity fills thinner sections than ABS but sinks badly above 3 mm on a boss or rib root.","applies":["pc","polycarbonate","injection molding","housing"],"value":{"min":1.5,"max":3,"typical":2,"unit":"mm"},"basis":"Standard PC moulding wall-thickness guidance","sources":["protolabs-guide"],"tags":["wall","pc","injection-molding"],"check":{"process":"injection_molding","rule":"min_wall_thickness"}},{"id":"wall-thickness-pp","kind":"dimension","tier":1,"title":"Nominal wall thickness, polypropylene (PP) injection moulding","summary":"PP housings and living-hinge parts run a 1.0-3.0 mm nominal wall; PP's low shrink-sensitivity tolerates the thin end of the range better than ABS/PC.","applies":["pp","polypropylene","injection molding","housing","living hinge"],"value":{"min":1,"max":3,"typical":2,"unit":"mm"},"basis":"Standard PP moulding wall-thickness guidance","sources":["protolabs-guide"],"tags":["wall","pp","injection-molding"],"check":{"process":"injection_molding","rule":"min_wall_thickness"}},{"id":"wall-thickness-pa","kind":"dimension","tier":1,"title":"Nominal wall thickness, polyamide (PA/nylon) injection moulding","summary":"PA/nylon housings and clips run a 1.0-3.0 mm nominal wall; PA's fast crystallisation and moisture uptake favour the thinner, more uniform end of the range.","applies":["pa","nylon","injection molding","housing","snap fit"],"value":{"min":1,"max":3,"typical":2,"unit":"mm"},"basis":"Standard PA66/PA6 moulding wall-thickness guidance","sources":["protolabs-guide"],"tags":["wall","pa","nylon","injection-molding"],"check":{"process":"injection_molding","rule":"min_wall_thickness"}},{"id":"wall-thickness-pom","kind":"dimension","tier":1,"title":"Nominal wall thickness, acetal (POM) injection moulding","summary":"POM (acetal) parts, common for latches and gears in a housing, run a 1.5-3.0 mm nominal wall; POM shrinks more than ABS/PC so wall uniformity matters more, not less.","applies":["pom","acetal","delrin","injection molding"],"value":{"min":1.5,"max":3,"typical":2,"unit":"mm"},"basis":"Standard POM/acetal moulding wall-thickness guidance","sources":["protolabs-guide"],"tags":["wall","pom","acetal","injection-molding"],"check":{"process":"injection_molding","rule":"min_wall_thickness"}},{"id":"wall-thickness-tpe-overmold","kind":"dimension","tier":1,"title":"Nominal wall thickness, TPE overmould layer","summary":"A TPE (thermoplastic elastomer) soft-touch overmould skin runs 1.0-2.0 mm thick over a rigid substrate; thinner tears on demould, thicker adds cost and can telegraph substrate features.","applies":["tpe","overmold","soft touch","housing"],"value":{"min":1,"max":2,"typical":1.5,"unit":"mm"},"basis":"Common two-shot TPE overmould skin-thickness guidance","sources":["protolabs-guide"],"tags":["wall","tpe","overmold"],"see":["hardware/screw-boss-plastic"]},{"id":"wall-thickness-fdm","kind":"dimension","tier":1,"title":"Nominal wall thickness, FDM-printed housing","summary":"An FDM-printed housing wall runs 1.6-2.4 mm, i.e. 4-6 perimeters at a common 0.4 mm nozzle/extrusion width, to be self-supporting and hold a heat-set insert.","applies":["fdm","3d printing","housing"],"value":{"min":1.6,"max":2.4,"typical":2,"unit":"mm","note":"4-6 perimeters at 0.4mm extrusion width"},"basis":"Wall-loop multiples of a common 0.4 mm nozzle width for a self-supporting rigid shell","sources":["hubs-3dp-guide"],"tags":["wall","fdm","3d-printing"]},{"id":"wall-thickness-sls","kind":"dimension","tier":1,"title":"Nominal wall thickness, SLS (PA12) housing","summary":"An SLS PA12-printed housing wall runs 1.0-1.5 mm; SLS's self-supporting powder bed lets it go thinner than FDM but thinner than 1 mm warps in the thermal cycle and breaks in depowdering.","applies":["sls","pa12","3d printing","housing"],"value":{"min":1,"max":1.5,"typical":1.2,"unit":"mm"},"basis":"PA12 SLS printable wall floor with a margin for depowdering handling","sources":["hubs-3dp-guide"],"tags":["wall","sls","pa12","3d-printing"]},{"id":"wall-thickness-sla","kind":"dimension","tier":1,"title":"Nominal wall thickness, SLA/resin housing","summary":"An SLA (resin) printed housing wall runs 1.0-2.0 mm; below 1 mm an unsupported wall warps or detaches during the build-plate peel.","applies":["sla","resin","3d printing","housing"],"value":{"min":1,"max":2,"typical":1.5,"unit":"mm"},"basis":"SLA unsupported-wall floor before peel-induced warping/detachment","sources":["hubs-3dp-guide"],"tags":["wall","sla","resin","3d-printing"]},{"id":"wall-uniformity","kind":"rule","tier":1,"title":"Wall thickness uniformity across a housing","summary":"Keep adjoining wall sections within ±25% of the nominal wall; a bigger step changes cooling rate enough to sink, warp or void at the transition, whatever the resin.","applies":["housing","injection molding"],"value":{"max":25,"unit":"%"},"basis":"Uniform-wall moulding guidance: differential shrinkage across a wall-thickness step is what drives sink and warp","sources":["protolabs-guide","fictiv-guide"],"tags":["wall","uniformity","sink"]},{"id":"draft-angle-minimum","kind":"rule","tier":1,"title":"Minimum draft angle on moulded housing walls","summary":"Draft every wall parallel to the pull direction at least 1°, 1.5-2° on a lightly textured (VDI 18-24) surface, 0.5° acceptable only on a high-polish (SPI A) surface with no texture.","applies":["housing","injection molding"],"value":{"min":0.5,"max":2,"typical":1,"unit":"deg"},"basis":"Published minimum 1-2 deg per side on any wall parallel to the pull; texture needs more draft to release cleanly, polish needs less","sources":["protolabs-guide","fictiv-guide"],"tags":["draft","mold-release"],"check":{"process":"injection_molding","rule":"min_draft_angle"}},{"id":"corner-radius-inside-outside","kind":"rule","tier":1,"title":"Internal and external corner radii","summary":"Radius every internal corner to at least 0.5x the local wall thickness and every matching external corner to the internal radius plus one wall thickness, so the wall stays a constant section around the bend.","applies":["housing","injection molding"],"value":{"min":0.5,"unit":"ratio","note":"inside >= 0.5x wall; outside = inside + wall"},"basis":"A sharp internal corner is the classic moulded-part stress riser and flow restriction; matching the outside radius keeps the wall a constant section","sources":["protolabs-guide","fictiv-guide"],"tags":["corner","radius","stress"],"check":{"process":"injection_molding","rule":"min_internal_corner_radius"}},{"id":"rib-design","kind":"rule","tier":1,"title":"Rib thickness, height and draft off a housing wall","summary":"Size a rib to <=0.6x the wall thickness at its root, <=3x the wall in height, with 0.5-1° draft per side and >=2x the wall between adjacent ribs, or the rib sinks the show surface and starves the mould of flow.","applies":["housing","rib","injection molding"],"value":{"max":0.6,"unit":"ratio","note":"root thickness/wall; height <= 3x wall; spacing >= 2x wall; draft 0.5-1 deg"},"basis":"Rib thickness <=60% of nominal wall avoids a sink mark on the opposite show surface; height/spacing limits keep the rib fillable and coolable","sources":["protolabs-guide","fictiv-guide"],"tags":["rib","sink","stiffener"],"check":{"process":"injection_molding","rule":"max_rib_thickness_ratio"}},{"id":"hole-depth-ratio-consumer","kind":"rule","tier":1,"title":"Blind cored-hole depth-to-diameter ratio","summary":"Keep a blind cored hole (screw boss bore, standoff pocket) to <=3x its diameter deep; a through hole supported at both ends can go to ~6x before the core pin deflects or breaks under injection pressure.","applies":["housing","boss","injection molding"],"value":{"max":3,"unit":"ratio","note":"blind hole depth:diameter; ~6x for a through hole"},"basis":"An unsupported core pin is a cantilever; beyond ~3x diameter it deflects enough to produce an off-axis or short hole","sources":["protolabs-guide","fictiv-guide"],"tags":["hole","core-pin","boss"],"check":{"process":"injection_molding","rule":"max_hole_depth_ratio"}},{"id":"snap-fit-cantilever-basics","kind":"feature","tier":1,"title":"Cantilever snap-fit beam proportions","summary":"A cantilever snap beam runs 5-10x its own thickness in length, deflecting within an allowable strain of ~3% for ABS or ~6% for PP, with a 0.5-1.5 mm undercut at the catch — go longer/thinner rather than deeper to stay under the strain limit.","applies":["snap fit","housing","clamshell"],"value":{"min":5,"max":10,"unit":"ratio","note":"beam length:thickness; strain limit ~3% ABS, ~6% PP; undercut 0.5-1.5mm"},"basis":"Beam-bending allowable strain for the resin sets the deflection a given length:thickness ratio can take without yielding on repeated cycles","sources":["bayer-snap-fit"],"tags":["snap-fit","cantilever","beam"]},{"id":"living-hinge-pp","kind":"feature","tier":1,"title":"Living hinge geometry in polypropylene","summary":"A PP living hinge runs 0.2-0.3 mm thick at the hinge web, 1.0-1.5 mm land on either side, 0.5-0.8 mm fillet radius into the land, and must be flexed in the mould within minutes of moulding while the polymer chains are still oriented.","applies":["living hinge","pp","housing"],"value":{"table":[{"param":"hinge-thickness","min":0.2,"max":0.3},{"param":"land-width","min":1,"max":1.5},{"param":"fillet-radius","min":0.5,"max":0.8}],"unit":"mm"},"basis":"PP's high fatigue resistance only develops when the hinge web is flexed while molecular orientation from the fill is still fresh, typically within minutes of ejection","sources":["dupont-living-hinge"],"tags":["living-hinge","pp","flex"]},{"id":"battery-aa-compartment-consumer","kind":"dimension","tier":1,"title":"AA/AAA battery compartment for a consumer housing","summary":"An AA cell (⌀14.5x50.5 mm) needs a pocket of ⌀15.5x51.5 mm and an AAA cell (⌀10.5x44.5 mm) a pocket of ⌀11.5x45.5 mm, each with 3-5 mm of spring-contact travel at one end to take up cell-length tolerance.","applies":["battery","aa","aaa","housing"],"value":{"table":[{"param":"aa-pocket","diameter":15.5,"length":51.5},{"param":"aaa-pocket","diameter":11.5,"length":45.5}],"unit":"mm"},"basis":"IEC 60086 cell envelope plus 0.5-1mm assembly clearance and 3-5mm spring-contact travel","sources":["iec-60086"],"tags":["battery","aa","aaa","compartment"]},{"id":"button-key-travel","kind":"dimension","tier":1,"title":"Button/keycap travel and key gap","summary":"Size a moulded button or keycap for 0.3-1.5 mm of travel before it bottoms out, with a 0.2-0.3 mm gap to its neighbour so adjacent keys don't bind or let liquid track sideways between them.","applies":["button","keycap","housing","remote control"],"value":{"min":0.3,"max":1.5,"unit":"mm","note":"travel; key-to-key gap 0.2-0.3mm"},"basis":"Tactile-dome and silicone-pad button travel range balancing feel against bottoming-out force spikes","sources":["protolabs-guide"],"tags":["button","keycap","travel"]}]}