Thorlabs 25mm pedestal pillar posts (large tap option) screw size
M6 · length not stated in the sources
If you are replacing a screw on Thorlabs 25mm pedestal pillar posts (large tap option), the thread is M6. None of the sources we found gives an exact length, so measure the original before you order.
It is listed for same page lists 1/4-20 (M6) taps as the metric large-thread option.
This entry is marked confirmed and comes from thorlabs.com.
For reference, M6 is 6 mm across the threads at 1 mm pitch. The imperial size people confuse it with: 1/4in-20 (6.35 mm) — the tripod/camera thread; visibly larger than M6.
Thorlabs 25mm pedestal pillar posts (large tap option) 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 |
|---|---|---|---|---|---|---|
| M6 | not stated | 1 mm | not stated | not stated | Same page lists 1/4-20 (M6) taps as the metric large-thread option | Confirmed |
Fitment records and sources
Same page lists 1/4-20 (M6) taps as the metric large-thread option
pitch 1 mm · tap 5 mm · clearance 6.6 mm · PH3 / Torx T30
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 M6 screw measures about 6 mm with calipers (usually a hair under). If yours measures noticeably more or less, it is a different thread.
- Pitch: 1 mm from one thread crest to the next (10 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 M6 heads take PH3 for Phillips and T30 for Torx, and a 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 M6 is about 7-10 N·m into metal threads and 2.5-4.0 N·m into plastic bosses; snug it up and stop.
Common mix-ups with M6
- TS-Optics Losmandy-style dovetail bars drill through-holes sized to accept either M6 metric screws or 1/4" imperial screws interchangeably in the same countersunk holes.
- 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 Thorlabs 25mm pedestal pillar posts (large tap option), closest length match first.
- AV equipment rack cage-nut kit also M6
- Windshield ADAS camera bracket also M6
- Newport M-RS2000-410-8 optical table also M6
- TS-Optics Vixen-EQ5 Style Dovetail Bar (255mm) also M6
- Newport M-RPR-46-8 optical table also M6
- Newport M-SG-36-2 honeycomb optical table also M6
- Newport M-RPR-410-8 optical table also M6
- Newport M-UCS-310-8 cleanroom optical table also M6
Questions about Thorlabs 25mm pedestal pillar posts (large tap option) screws
- What size screw does Thorlabs 25mm pedestal pillar posts (large tap option) use?
- M6 for same page lists 1/4-20 (M6) taps as the metric large-thread option.
- How long are the screws in Thorlabs 25mm pedestal pillar posts (large tap option)?
- 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 M6 screw?
- 1 mm (coarse), which is the standard pitch for M6 machine screws; a 0.75 mm fine pitch exists but is uncommon. The tap drill is 5 mm and the normal clearance hole is 6.6 mm.
- What screwdriver do I need for Thorlabs 25mm pedestal pillar posts (large tap option)?
- The sources do not name the drive. For M6, Phillips heads normally take PH3 and Torx heads T30; socket heads take a 5 mm hex key.
- Can I use an imperial screw instead of M6?
- No. Imperial look-alike: 1/4in-20 (6.35 mm) — the tripod/camera thread; visibly larger than M6. Use a true M6 screw so it does not cross-thread or strip the hole.