⚡ Key Takeaways
- Four product families: press-in nuts with nylon locking, screws (ultra-low head, CD texture), inserts that reinforce plastics, and PCB/SMT nuts.
- Reinforcing plastic: inserts in brass, stainless steel or titanium survive repeated assembly without damaging the plastic boss.
- SMT: tin-plated copper nuts reflow onto small boards, supplied on tape and reel, and create a thread after soldering.
- Ultra-low heads: internal space in a phone is minimal, so CD texture, JIS and Y drives are all customisable.
- Anti-loosening: locking teeth under the head (mechanical) plus pre-applied adhesive (chemical).
- Sealing: adhesive or an O-ring under the head or on the thread reaches IP68.
- Process optimisation case: converting a die-cast part to cold heading cut cost by about RMB 0.75 per piece — RMB 375,000 across 100,000 pieces.
1. What makes consumer electronics different
2. The four product families
3. PCB and SMT nuts
4. Process optimisation: die casting to cold heading
5. Selection logic and FAQ
1. What makes consumer electronics different
Phones, tablets, laptops and wearables ask something quite different of a fastener than automotive does:
- Tiny dimensions: M1.2–M3 micro screws with heads 1–2 mm high;
- Appearance: CD texture, plain anodising, no scratches;
- Automated assembly: tape-and-reel packaging for SMT pick-and-place;
- Repeated assembly: service work must not strip the plastic boss;
- Light weighting: titanium and aluminium where it counts.
2. The four product families
2.1 Press-in nuts with nylon locking
Used to fasten consumer electronics sheet metal. A nylon ring provides the locking and retention, and the part is set with press-in tooling.
2.2 Screws: ultra-low head, CD texture, locking and sealing
- Locking teeth under the head (mechanical) plus pre-applied threadlocking adhesive (chemical);
- Ultra-low head styles with CD texture, JIS and Y drives;
- Adhesive or an O-ring under the head or on the thread gives sealing up to IP68.
2.3 Inserts that reinforce plastics
They strengthen the thread in a plastic part so the screw can be removed and refitted repeatedly. Materials: brass, stainless steel, titanium.
2.4 PCB applications (SMT)
Tin-plated copper nuts and small plates are soldered to the PCB to create a thread, and can also act as a standoff. They are available on tape and reel for SMT placement. Super screws connect stacked PCBs and attach boards to sheet metal.
3. PCB and SMT nuts
| Type | Process | Use |
|---|---|---|
| Tin-plated copper nut | Reflowed onto the PCB | Threaded connection, standoff |
| Tape and reel | Pick-and-place | Automated lines |
| Super screw | — | Stacked PCBs, board to sheet metal |
4. Process optimisation: die casting to cold heading
This is the classic 15%/85% pattern in consumer electronics: the purchase price moves by cents, but process optimisation moves total cost substantially.
5. Selection logic and FAQ
Three questions
- Is the parent part plastic? Then a brass or stainless insert.
- Does it need SMT placement? Then a tin-plated copper nut on tape and reel.
- Is head height limited? Then an ultra-low head with custom CD texture.
FAQ
Q: Why titanium in phones? Very light, strong and non-magnetic, but expensive — reserved for critical parts in flagship models.
Q: How many re-assemblies does a nylon locking nut survive? Typically 5–10; after that the nylon patch wears and locking torque drops.
Q: Do SMT nuts survive reflow? Yes, tin-plated copper handles reflow temperatures with a 260°C peak.
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