Shimano derailleur limit screws (H/L limit and B-tension) screw size
M4 · 10 to 12 mm long
If you are replacing a screw on Shimano derailleur limit screws (H/L limit and B-tension), the thread is M4 in lengths from 10 to 12 mm.
Where it is used: shunTool guide states 'Shimano derailleur limit screws are typically M4 size ... DA screws are M4 x 11.5 for the rear RD and M4 x 10 for the FD. The B screw is M4 x 12'.
This entry is marked reported and comes from shuntool.com.
For reference, M4 is 4 mm across the threads at 0.7 mm pitch. The imperial size people confuse it with: #8-32 (4.17 mm) — the standard US PC/rack screw, close but not the same.
Shimano derailleur limit screws (H/L limit and B-tension) 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 |
|---|---|---|---|---|---|---|
| M4 | 10–12 mm | 0.7 mm | not stated | not stated | ShunTool guide states 'Shimano derailleur limit screws are typically M4 size ... DA screws are M4 x 11.5 for the rear RD and M4 x 10 for the FD. The B screw is M4 x 12' | Reported |
Fitment records and sources
ShunTool guide states 'Shimano derailleur limit screws are typically M4 size ... DA screws are M4 x 11.5 for the rear RD and M4 x 10 for the FD. The B screw is M4 x 12'
pitch 0.7 mm · tap 3.3 mm · clearance 4.5 mm · PH2 / Torx T20
How to check the screw before you buy
- On vehicles and bikes, use the original strength class and finish; outdoor hardware is usually stainless or coated to resist corrosion.
- Diameter: across the threads an M4 screw measures about 4 mm with calipers (usually a hair under). If yours measures noticeably more or less, it is a different thread.
- Pitch: 0.7 mm from one thread crest to the next (14.29 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.
- The records span 10–12 mm, which means different positions take different lengths — match each hole to its own screw.
- Driver: the source does not name the drive. Standard M4 heads take PH2 for Phillips and T20 for Torx, and a 3 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 M4 is about 2.0-3.0 N·m into metal threads and 0.8-1.4 N·m into plastic bosses; snug it up and stop.
Common mix-ups with M4
- M4 and 6-32 UNC share a nominal diameter with different pitch — a classic cross-thread in US-market kits.
Buy these screws at TechSpare Warehouse
In stock and shipped from South Carolina. Our black screws are Phillips wafer head (low profile); match the head style and length to the original before you order.
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M4 x 10mm Black Wafer Head Charging Port Screws for GOTRAX G3, G4, GMAX & GMAX Ultra – 10-Pack Replacement
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M4 x 10mm Black Wafer Head Fender Clamp Base Screws for Minoura KODACHI DYK-1R Rear Fender – 8-Pack Replacement
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M4 x 12mm Black Wafer Head Chainsaw & Cut-off Saw Screws for STIHL MS 460, MS 362, TS480i & TS500i (IS-M4x12) – 10-Pack Replacement
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M4 x 12mm Black Wafer Head Monitor VESA, Neck & Stand Screws for Dell UltraSharp U4320Q & Sceptre Monitors – 8-Pack Replacement
$5.49Choose size
More in Vehicles, Marine & Mobility
The same screw also fits
Devices whose records share a thread with Shimano derailleur limit screws (H/L limit and B-tension), closest length match first.
- Phoenix Contact CHARX EV-T1CCS charging inlet repair kit also M4 × 10 mm
- Car badge / emblem studs also M4 × 10 mm
- RV / camper cabinet hardware also M4 × 10–12 mm
- Shimano BL-M785 hydraulic brake lever also M4 × 12 mm
- Car centre console and vent trim also M4 × 10–12 mm
- NovAtel SMART7 GNSS smart antenna also M4 × 12 mm
- EVBox Troniq Compact Modular also M4 × 12 mm
- Shimano Ultegra RD-6700 rear derailleur also M4 × 11.5 mm
Questions about Shimano derailleur limit screws (H/L limit and B-tension) screws
- What size screw does Shimano derailleur limit screws (H/L limit and B-tension) use?
- M4 × 10–12 mm for shunTool guide states 'Shimano derailleur limit screws are typically M4 size ... DA screws are M4 x 11.5 for the rear RD and M4 x 10 for the FD. The B screw is M4 x 12'.
- How long are the screws in Shimano derailleur limit screws (H/L limit and B-tension)?
- The records range from 10 to 12 mm depending on the position, so match each screw to its own hole.
- What is the thread pitch of an M4 screw?
- 0.7 mm (coarse), which is the standard pitch for M4 machine screws; a 0.5 mm fine pitch exists but is uncommon. The tap drill is 3.3 mm and the normal clearance hole is 4.5 mm.
- What screwdriver do I need for Shimano derailleur limit screws (H/L limit and B-tension)?
- The sources do not name the drive. For M4, Phillips heads normally take PH2 and Torx heads T20; socket heads take a 3 mm hex key.
- Can I use an imperial screw instead of M4?
- No. Imperial look-alike: #8-32 (4.17 mm) — the standard US PC/rack screw, close but not the same. Use a true M4 screw so it does not cross-thread or strip the hole.