Brompton folding bicycle main/front frame assembly screw size
M3 · length not stated in the sources
Our records put Brompton folding bicycle main/front frame assembly on M3 screws. None of the sources we found gives an exact length, so measure the original before you order.
Where it is used: official Brompton trade datasheet labels an M3 fastener in the main/front frame hinge assembly diagram (fig DR9).
This entry is marked confirmed and comes from trade.brompton.com.
M3 means a 3 mm nominal diameter with a 0.5 mm thread pitch. Imperial look-alike: #5-40 (3.18 mm) or #4-40 — neither interchanges with M3.
Brompton folding bicycle main/front frame assembly 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 |
|---|---|---|---|---|---|---|
| M3 | not stated | 0.5 mm | not stated | not stated | Official Brompton trade datasheet labels an M3 fastener in the main/front frame hinge assembly diagram (fig DR9) | Confirmed |
Fitment records and sources
Official Brompton trade datasheet labels an M3 fastener in the main/front frame hinge assembly diagram (fig DR9)
pitch 0.5 mm · tap 2.5 mm · clearance 3.4 mm · PH1 / Torx T10
How to check the screw before you buy
- Keep material and finish the same as the original (often stainless) on equipment that is cleaned or sterilised.
- Diameter: across the threads an M3 screw measures about 3 mm with calipers (usually a hair under). If yours measures noticeably more or less, it is a different thread.
- Pitch: 0.5 mm from one thread crest to the next (20 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 M3 heads take PH1 for Phillips and T10 for Torx, and a 2.5 mm hex key for socket heads; 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 M3 is about 80-130 N·cm into metal threads and 35-60 N·cm into plastic bosses; snug it up and stop.
Common mix-ups with M3
- The bioprinter M3 reference is a tube-connector thread spec, not a structural chassis screw; verify before assuming interchangeability with fastener screws.
- Pond/aquarium equipment manuals aimed at consumers rarely specify exact thread pitch or length for internal fasteners, since these are considered non-user-serviceable; distributor-level assembly/service manuals (e.g., Maytronics internal documents) are a better source than end-user guides.
More in Medical & Laboratory
The same screw also fits
Devices whose records share a thread with Brompton folding bicycle main/front frame assembly, closest length match first.
- TSC MB241/MB341 industrial label printer also M3
- ResMed VPAP / S8 service hardware also M3
- Thorlabs SP01 blank 16mm cage plate, 0.25" thick also M3
- Kendro / Sorvall Legend T and Multifuge 3S/3L centrifuge also M3
- cab XD4T industrial label printer also M3
- ResMed S9 Elite CPAP chassis also M3
- BMC RESmart CPAP machine also M3
- Kaycee Microfish veterinary tube-feed repeater syringe also M3
Questions about Brompton folding bicycle main/front frame assembly screws
- What size screw does Brompton folding bicycle main/front frame assembly use?
- M3 for official Brompton trade datasheet labels an M3 fastener in the main/front frame hinge assembly diagram (fig DR9).
- How long are the screws in Brompton folding bicycle main/front frame assembly?
- 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 M3 screw?
- 0.5 mm (coarse), which is the standard pitch for M3 machine screws; a 0.35 mm fine pitch exists but is uncommon. The tap drill is 2.5 mm and the normal clearance hole is 3.4 mm.
- What screwdriver do I need for Brompton folding bicycle main/front frame assembly?
- The sources do not name the drive. For M3, Phillips heads normally take PH1 and Torx heads T10; socket heads take a 2.5 mm hex key.
- Can I use an imperial screw instead of M3?
- No. Imperial look-alike: #5-40 (3.18 mm) or #4-40 — neither interchanges with M3. Use a true M3 screw so it does not cross-thread or strip the hole.