Thorlabs nested rotation mounts screw size
M4 · length not stated in the sources
If you are replacing a screw on Thorlabs nested rotation mounts, the thread is M4. None of the sources we found gives an exact length, so measure the original before you order.
Where it is used: page lists 8-32 (M4) tap for post mounting on metric variants.
This entry is marked confirmed and comes from thorlabs.com.
M4 means a 4 mm nominal diameter with a 0.7 mm thread pitch. Imperial look-alike: #8-32 (4.17 mm) — the standard US PC/rack screw, close but not the same.
Thorlabs nested rotation mounts 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 | not stated | 0.7 mm | not stated | not stated | Page lists 8-32 (M4) tap for post mounting on metric variants | Confirmed |
Fitment records and sources
Page lists 8-32 (M4) tap for post mounting on metric variants
pitch 0.7 mm · tap 3.3 mm · clearance 4.5 mm · PH2 / Torx T20
How to check the screw before you buy
- Camera and optics hardware often uses short screws into thin threaded plates, so check engagement before tightening fully.
- 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.
- 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
- Display mounts mix systems: the screen side is metric M4/M6, but the wall side of many mounts uses imperial wood screws such as #14 x 2.5in.
- Pinball machines are historically imperial (UNC/UNF). Metric M4 shows up mainly in specific parts like cooling fans or in European rebuilds.
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Devices whose records share a thread with Thorlabs nested rotation mounts, closest length match first.
- Thorlabs DDR25/M direct drive rotation mount also M4
- Underwater camera housing latch and port also M4
- Tilta TA-RF-LPL adapter ring support (RED KOMODO cage) also M4
- Meade 2" to 1.25" eyepiece adapter / 1.25" visual back also M4
- Newport M-TSP-1 miniature post also M4
- Wooden Camera UMB-1 Universal Mattebox (Base/Clamp On/Swing Away/Pro) also M4
- Thorlabs KS05T/M SM05 kinematic mirror mount also M4
- Thorlabs SMR1/M Ø1" lens mount with SM1 internal threads also M4
Questions about Thorlabs nested rotation mounts screws
- What size screw does Thorlabs nested rotation mounts use?
- M4 for page lists 8-32 (M4) tap for post mounting on metric variants.
- How long are the screws in Thorlabs nested rotation mounts?
- 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 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 Thorlabs nested rotation mounts?
- 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.