Newport M-SP-4 optical post screw size
M4 / M6 · length not stated in the sources
Newport M-SP-4 optical post takes M4 and M6 metric screws. None of the sources we found gives an exact length, so measure the original before you order.
There are 2 separate fitment records for it, including M4 tapped hole one end, M6 the other; 101.6 mm post (M4) and M6 tapped hole one end, M4 the other; 101.6 mm post (M6).
2 of the 2 records are marked confirmed, drawn from 1 source (newport.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.
Newport M-SP-4 optical post 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 | M4 tapped hole one end, M6 the other; 101.6 mm post | Confirmed |
| M6 | not stated | 1 mm | not stated | not stated | M6 tapped hole one end, M4 the other; 101.6 mm post | Confirmed |
Fitment records and sources
M4 tapped hole one end, M6 the other; 101.6 mm post.
pitch 0.7 mm · tap 3.3 mm · clearance 4.5 mm · PH2 / Torx T20
M6 tapped hole one end, M4 the other; 101.6 mm post.
pitch 1 mm · tap 5 mm · clearance 6.6 mm · PH3 / Torx T30
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 M4 screw measures about 4 mm with calipers (usually a hair under). This device also uses M6, so measure each screw rather than assuming they match.
- 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 / M6
- M4 and 6-32 UNC share a nominal diameter with different pitch — a classic cross-thread in US-market kits.
- Optical breadboards are metric only when the part number ends in /M; the default in North America is 1/4-20.
- Optical tables come in metric (M6 on 25mm centres) and imperial (1/4-20 on 1in centres) — mixing them cross-threads the table.
More in Cameras & Optics
The same screw also fits
Devices whose records share a thread with Newport M-SP-4 optical post, closest length match first.
- Cognex In-Sight 9000 machine vision system also M4
- Newport M-SP-2 / M-SP-4 optical posts also M4
- Christie HS / Jazz Series UST lens bracket also M4
- DJI RS upper quick-release plate also M4
- Shield Sights Optic Ready (MOS) Mount also M4
- Cinema camera cheese plates & cages also M6
- Wimberley AP-609 lens foot plate also M4
- ScopeStuff nylon thumbscrew kit also M4
Questions about Newport M-SP-4 optical post screws
- What size screw does Newport M-SP-4 optical post use?
- M4 for M4 tapped hole one end, M6 the other; 101.6 mm post; M6 for M6 tapped hole one end, M4 the other; 101.6 mm post.
- How long are the screws in Newport M-SP-4 optical post?
- 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 Newport M-SP-4 optical post?
- 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.