ISMS Picatinny scope mount rail clamp screw size
M5 · length not stated in the sources
Our records put ISMS Picatinny scope mount rail clamp on M5 screws. None of the sources we found gives an exact length, so measure the original before you order.
It is listed for manual states M5 Torx-20 clamping screws to clamp the mount to the rail.
Head and drive, as the source states them: Torx T20 drive.
This entry is marked confirmed and comes from gunsmoke.eu.
M5 means a 5 mm nominal diameter with a 0.8 mm thread pitch. Imperial look-alike: #10-32 (4.83 mm) — the other common rack thread; check before mixing.
ISMS Picatinny scope mount rail clamp 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 |
|---|---|---|---|---|---|---|
| M5 | not stated | 0.8 mm | not stated | Torx T20 | Manual states M5 Torx-20 clamping screws to clamp the mount to the rail | Confirmed |
Fitment records and sources
Manual states M5 Torx-20 clamping screws to clamp the mount to the rail
pitch 0.8 mm · tap 4.2 mm · clearance 5.5 mm · PH2 / Torx T25
How to check the screw before you buy
- Do not confuse metric mounting screws with the 1/4-20 or 3/8-16 tripod threads that cameras and clamps also carry.
- Diameter: across the threads an M5 screw measures about 5 mm with calipers (usually a hair under). If yours measures noticeably more or less, it is a different thread.
- Pitch: 0.8 mm from one thread crest to the next (12.5 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 names a Torx T20 drive. For comparison, standard M5 heads take PH2 (Phillips) or T25 (Torx), or a 4 mm hex key.
- Tightening: no device-specific torque is published in these records. The site's general figure for M5 is about 4.0-6.0 N·m into metal threads and 1.5-2.5 N·m into plastic bosses; snug it up and stop.
Common mix-ups with M5
- M5x0.8 is the de facto universal bike thread — confirm 0.8mm pitch before threading into carbon or alloy bosses.
More in Cameras & Optics
The same screw also fits
Devices whose records share a thread with ISMS Picatinny scope mount rail clamp, closest length match first.
- Kayak and canoe accessory rail track also M5
- GoPro thumbscrew/nut (scope mount project) also M5
- GoPro Universal Car Mounts also M5
- NewBeeDrone action camera mount kit also M5
- GoPro mount thumbscrew also M5
- Alpine and touring ski bindings (Binding Freedom inserts) also M5
- GoPro HERO action-camera mount thumbscrew/buckle system also M5
- Camera cage accessory arms also M5
Questions about ISMS Picatinny scope mount rail clamp screws
- What size screw does ISMS Picatinny scope mount rail clamp use?
- M5 for manual states M5 Torx-20 clamping screws to clamp the mount to the rail.
- How long are the screws in ISMS Picatinny scope mount rail clamp?
- 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 M5 screw?
- 0.8 mm (coarse), which is the standard pitch for M5 machine screws; a 0.5 mm fine pitch exists but is uncommon. The tap drill is 4.2 mm and the normal clearance hole is 5.5 mm.
- What screwdriver do I need for ISMS Picatinny scope mount rail clamp?
- The source lists a Torx T20 drive. Standard M5 heads otherwise take PH2 (Phillips) or T25 (Torx), or a 4 mm hex key.
- Can I use an imperial screw instead of M5?
- No. Imperial look-alike: #10-32 (4.83 mm) — the other common rack thread; check before mixing. Use a true M5 screw so it does not cross-thread or strip the hole.