Acetal (POM)
- Good flex fatigue for snaps that open repeatedly
- Stable size in humid air compared with nylon
- Brittle in very cold impact if the root is sharp
Molded part guide: clips
Injection Molded Clips and Retainers
Clip is a broad label. Some clips snap onto a panel edge, some push into a slot once, and some spring open for service. The mold cares about the same things: engagement depth, release direction, and whether the stack of tolerances still holds.
The job
A clip is an interface, not a standalone part
Retention lives in the fit between the clip and whatever it catches.
Molded clips show up as trim retainers, wire holders, battery contacts, and cover catches. What they share is a flexible member or spring form that deflects on assembly and pushes back to hold. What differs is how often it opens, how much panel thickness variation you must absorb, and whether the clip or the panel is allowed to flex.
Nominal CAD dimensions rarely tell the whole story. Mold shrink, warpage on a long beam, and the thinnest and thickest panel in tolerance together decide whether the clip rattles or whether assembly feels like a hammer hit. DFM review starts from both parts and the insertion path.
Cantilever snap clips are the most common type in molded enclosures. They have their own guide at /molded-parts/snap-fit-clips. This page covers how to choose among clip styles and what to document before quoting steel.
Styles
Common molded clip types and when each fits
General behavior. Your assembly sequence picks the type.
| Type | How it retains | Molding note |
|---|---|---|
| Cantilever snap | Hook flexes over a ledge or into a window | Hook undercut may need a slide; see snap-fit clip guide |
| Push-on arrow clip | Flexible legs spread and lock in a hole or slot | Legs must eject without tearing; draft on legs matters |
| Spring finger | Curved beam presses on a panel or contact | Fatigue and creep if the finger stays loaded for months |
| Edge clip | Jaws grip panel thickness at the rim | Must span min and max panel thickness without overstrain |
Resin
Acetal, nylon, or PP for a clip
Clip resin is picked for flex fatigue and environment, not peak tensile alone.
Nylon or PP
- Nylon absorbs shock well; moisture changes beam stiffness
- PP suits low-cost push clips and living hinge adjacent features
- Glass fill stiffens the beam and raises assembly force
Drawing
What to send with a clip design
Include the part the clip mates to.
Clip CAD and the panel, slot, or ledge it engages
Insertion direction and whether release is toolless
One-time assembly or expected open cycles
Panel thickness tolerance range the clip must span
Sustained load while engaged, such as seal preload or anti-rattle
Cosmetic face on the clip and whether sink is visible
Keep reading
Related guides
Specialized clip and DFM topics.
Snap fit clips
Cantilever beam clips in detail.
Snap fit clipsCable clips
Routing bundles without crushing conductors.
Cable clipsCantilever snap fit
Beam math and strain limits.
Cantilever snap fitTolerance stack up
Worst-case engagement on clips.
Tolerance stack upLatches
Enclosure-scale catches.
LatchesAcetal (POM)
Common clip resin.
Acetal (POM)Side actions
When the hook cannot strip.
Side actionsEnclosures
Clips on two-shell products.
EnclosuresMolded parts hub
Every part-type guide, grouped by family.
Molded parts hubFAQ
Questions about molded clips
Can you mold a clip onto our enclosure in the same tool?
Yes, when the clip is on the same parting line and resin as the shell. Send the full assembly CAD so engagement with the mate is reviewed.
Our clip is loose at minimum panel thickness. Is that a mold problem?
Often it is a tolerance stack issue first. Check minimum engagement against minimum panel and maximum slot width before changing cavity steel.
Do you publish a standard clip catalog?
No. NetProto quotes clips from your CAD in a hardened steel tool. There is no MOQ beyond your order quantity, and you own the tool.
Can glass-filled nylon be used for a flex clip?
It can, but the beam becomes stiffer and the root is more notch sensitive. Many high-cycle clips stay unfilled acetal or unfilled nylon.
Next step
Quote the clip with its mate geometry
Upload clip and panel CAD with insertion path and tolerance limits. DFM feedback covers engagement, ejection, and beam risk.