Watch case-back screw screw size
M1.2 · length not stated in the sources
The screws used on Watch case-back screw are M1.2. None of the sources we found gives an exact length, so measure the original before you order.
Where it is used: stainless steel watch back case screw kit sold explicitly as 1.2mm/1.4mm/2.0mm diameter screws for watchmakers, used to secure watch case backs.
This entry is marked confirmed and comes from gewatchparts.com.
An M1.2 screw is 1.2 mm in diameter with a 0.25 mm pitch, tapped with a 0.95 mm drill; imperial look-alike: #0-80 UNF (1.52 mm) is the closest imperial screw, but it is bigger — not a substitute.
Watch case-back screw screw specifications
One row per fitment record. Head, drive are shown only where the source states them; pitch is the ISO coarse pitch for the thread.
| Thread | Length | Pitch | Head | Drive | Where it goes | Status |
|---|---|---|---|---|---|---|
| M1.2 | not stated | 0.25 mm | not stated | not stated | Stainless steel watch back case screw kit sold explicitly as 1.2mm/1.4mm/2.0mm diameter screws for watchmakers, used to secure watch case backsstainless | Confirmed |
Fitment records and sources
Stainless steel watch back case screw kit sold explicitly as 1.2mm/1.4mm/2.0mm diameter screws for watchmakers, used to secure watch case backs
pitch 0.25 mm · tap 0.95 mm · clearance 1.4 mm · PH000 / JIS 00 / Torx T1–T2
How to check the screw before you buy
- Phone and wearable screws are tiny and often differ by fractions of a millimetre between positions; keep each one next to the hole it came from.
- Diameter: across the threads an M1.2 screw measures about 1.2 mm with calipers (usually a hair under). If yours measures noticeably more or less, it is a different thread.
- Pitch: 0.25 mm from one thread crest to the next (40 crests per centimetre). A thread pitch gauge or the pitch-gauge tool settles it in seconds.
- Length: measure from under the head to the tip for pan, button, wafer and cap heads; countersunk (flat) heads are measured overall.
- Driver: the source does not name the drive. Standard M1.2 heads take PH000 / JIS 00 for Phillips and T1–T2 for Torx; a bit that fits loosely will cam out and strip the head.
- Tightening: no device-specific torque is published in these records. The site's general figure for M1.2 is about 5-8 N·cm into metal threads and 3-5 N·cm into plastic bosses; snug it up and stop.
Common mix-ups with M1.2
- 'Universal' eyeglass kits mislabel diameter vs shaft: a listed 1.2 can measure 1.19-1.3mm between brands.
- M1.2 and M1.4 look identical in an eyeglass repair kit — the wrong one strips soft acetate or metal hinges.
More in Phones, Tablets & Wearables
The same screw also fits
Devices whose records share a thread with Watch case-back screw, closest length match first.
- Valve Steam Deck (LCD) also M1.2
- Watch case back screw (small cases) also M1.2
- Watch dial foot / movement ring also M1.2
- Smartphone antenna clips (some OEMs) also M1.2
- Watch case micro screw (Nylok) also M1.2
- Watch casebacks & bracelet links also M1.2
- Apple Watch strap adapter also M1.2
- Samsung Galaxy S24 also M1.2
Questions about Watch case-back screw screws
- What size screw does Watch case-back screw use?
- M1.2 for stainless steel watch back case screw kit sold explicitly as 1.2mm/1.4mm/2.0mm diameter screws for watchmakers, used to secure watch case backs.
- How long are the screws in Watch case-back screw?
- None of the sources states a length. Remove one screw and measure it from under the head to the tip (overall for a countersunk head).
- What is the thread pitch of an M1.2 screw?
- 0.25 mm (coarse), which is the standard pitch for M1.2 machine screws. The tap drill is 0.95 mm and the normal clearance hole is 1.4 mm.
- What screwdriver do I need for Watch case-back screw?
- The sources do not name the drive. For M1.2, Phillips heads normally take PH000 / JIS 00 and Torx heads T1–T2.
- Can I use an imperial screw instead of M1.2?
- No. Imperial look-alike: #0-80 UNF (1.52 mm) is the closest imperial screw, but it is bigger — not a substitute. Use a true M1.2 screw so it does not cross-thread or strip the hole.