⚡ Key Takeaways
- Range: M0.8–M2.0, covering phones, earbuds, watches and laptops.
- Thread form: machine screw (M, used with a nut or pre-tapped hole) versus self-tapping (B/ST, cuts its own thread in plastic or thin sheet).
- Drive: Phillips, Torx, Torx Plus, eleven-slot, hex socket, slotted, Tri-wing Y and Pozidriv.
- Head: pan C, small pan P and countersunk F.
- Material: carbon steel SWRCH10A/18A/22A; stainless SUS302HQ/304/316/410; titanium TA2.
- Appearance: PVD vacuum coating, CD texture and nano coatings that do not fade or peel.
📑 Contents
1. What makes micro screws different
2. Machine thread versus self-tapping
3. Size table (M0.8–M2.0)
4. Choosing the drive and head
5. PVD CD-texture decorative screws
6. Material choice and torque
1. What makes micro screws different
2. Machine thread versus self-tapping
3. Size table (M0.8–M2.0)
4. Choosing the drive and head
5. PVD CD-texture decorative screws
6. Material choice and torque
1. What makes micro screws different
From the handbook: precision screws for consumer electronics combine micro dimensions with high precision, high strength and vibration resistance, non-magnetic low interference, and stable, reliable driving — a perfect fit for slim, highly integrated products built on automated assembly.
How they work: turning the screw converts torque into axial clamping force (preload is typically 70–80% of the breaking torque), clamping the parts through the engaged thread.
2. Machine thread versus self-tapping
| Type | Characteristics | Applications |
|---|---|---|
| Machine thread (M) | Coarse or fine pitch, used with a nut or a pre-tapped hole; can be reassembled repeatedly; high clamping force with stable torque | Phone mid-frames, metal brackets, metal back covers, mainboard mounting, thermal modules, shield-can pivots, hinges, camera modules |
| Self-tapping (B/ST) | Forms its own thread (sharp point A, blunt point B, wide thread, coarse pitch); driven into a prepared pilot hole in plastic or thin metal; not intended for repeated assembly; below M2 a sharp point is usually omitted | Plastic housings, battery covers, cosmetic parts, earbud charging cases, router shells, light-duty plastic brackets inside small appliances |
Note for self-tapping below M2: match the pilot hole to the industry-standard pitch, keep 3–5 threads engaged and maintain minimum wall thickness to avoid stripping, screw breakage and cracked plastic.
3. Size table (machine thread, M0.8–M2.0)
| Size d×P | Head dia. a (min) | Head height b | Thread length c (min) | Slot depth q | Drive |
|---|---|---|---|---|---|
| M0.8×0.2P | 1.30 | 0.30±0.05 | 0.9 | 0.15 | Phillips 0# |
| M1.0×0.20P | 1.70 | 0.25±0.05 | 1.2 / 0.9 | 0.20 | Phillips 0# |
| M1.0×0.25P | |||||
| M1.2×0.20P | 1.90 | 0.30±0.05 | 1.4 / 1.1 | 0.30 | Phillips 0# |
| M1.2×0.25P | |||||
| M1.4×0.20P | 2.10 | 0.35±0.05 | 1.7 / 1.4 | 0.40 | Phillips 0# |
| M1.4×0.3P | |||||
| M1.6×0.2P | 2.40 | 0.45±0.05 | 1.9 / 1.6 | 0.50 | Phillips 0# |
| M1.6×0.35P | |||||
| M2.0×0.25P | 3.00 | 0.45±0.05 | 2.4 / 2.0 | 0.60 | Phillips 0# |
| M2.0×0.4P |
4. Choosing the drive and head
Drive
- Phillips: the most common choice;
- Torx / Torx Plus: for automated lines and high torque without cam-out;
- Eleven-slot: accepts two different screwdrivers;
- Hex socket: clean appearance, no visible slot;
- Tri-wing Y: tamper-resistant, common in consumer electronics;
- Pozidriv: higher torque.
Head
- Pan head C: the most common;
- Small pan P: low profile;
- Countersunk F: flush with the surface.
5. PVD CD-texture decorative screws
PVD (physical vapour deposition) atomises a target material in vacuum and deposits it on the part as a dense film from nanometres to a few micrometres thick.
- Very high hardness, wear and scratch resistant, so threads resist galling and chipping;
- Corrosion and rust protection, resistant to salt spray and humidity;
- The film is so thin that dimensions are unaffected — no clogged threads, no change in assembly clearance;
- Low friction and self-lubricating: smooth driving, stable torque, no stripping;
- No hydrogen embrittlement, environmentally safe, and an appearance that does not fade or peel.
6. Material choice and torque
| Material | Tensile strength | Characteristics | Applications |
|---|---|---|---|
| Carbon steel SWRCH10A | 300–400 MPa | Economical, easy to form, needs plating | General consumer electronics |
| Carbon steel SWRCH18A | 400–500 MPa | Moderately stronger | Medium structures |
| Stainless SUS302HQ | 500–700 MPa | Non-magnetic, corrosion resistant, most widely used | Phones, wearables |
| Stainless SUS316 | 550–700 MPa | Salt-spray resistant, medical grade | Outdoor, medical |
| Stainless SUS410 | 700–1000 MPa | High strength, hardenable | Structural parts |
| Titanium TA2 | 400–600 MPa | Light, non-magnetic, biocompatible | Medical, premium products |
Recommended driving torque (stainless M1.6)
| Thread | Recommended torque (N·cm) | Assembly location |
|---|---|---|
| M1.2 | 0.6–1.0 | Battery cover |
| M1.4 | 1.0–1.5 | Mid-frame |
| M1.6 | 1.5–2.5 | Mainboard |
| M2.0 | 3.0–5.0 | Thermal module |
The critical factor with micro screws: too little torque and the joint works loose; too much and the screw breaks or the thread strips. Automated lines need a torque-controlled driver held to ±10%.
FAQ
Q: Can M0.8 be run on an automated line? Yes, with a custom bit and a vacuum nozzle.
Q: What thread is used in an earbud charging case? Self-tapping ST1.2–ST1.6 driven straight into the plastic.
Q: Why use a Tri-wing Y drive? To stop users opening the product themselves, so the warranty stays intact.
🛠️ Engineering support: Toprecision supplies the full M0.8–M2.0 micro screw range, including PVD CD-texture decorative screws.
👉 Engineering services ｜ 👉 Request a technical quote
👉 Engineering services ｜ 👉 Request a technical quote