Orion Barlows/diagonal/finder screws (2x Deluxe Baffled Barlow 1997, 2x Ultrascopic Barlow 1999, 45-degree Erect-Image Diagonal 1999, 5x finder 3-point adjust 1997) screw size
M3 · length not stated in the sources
Orion Barlows/diagonal/finder screws (2x Deluxe Baffled Barlow 1997, 2x Ultrascopic Barlow 1999, 45-degree Erect-Image Diagonal 1999, 5x finder 3-point adjust 1997) takes M3 metric screws. None of the sources we found gives an exact length, so measure the original before you order.
It is listed for scopeStuff database lists all these Orion accessory screws as M3-.5.
This entry is marked confirmed and comes from scopestuff.com.
An M3 screw is 3 mm in diameter with a 0.5 mm pitch, tapped with a 2.5 mm drill; imperial look-alike: #5-40 (3.18 mm) or #4-40 — neither interchanges with M3.
Orion Barlows/diagonal/finder screws (2x Deluxe Baffled Barlow 1997, 2x Ultrascopic Barlow 1999, 45-degree Erect-Image Diagonal 1999, 5x finder 3-point adjust 1997) 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 |
|---|---|---|---|---|---|---|
| M3 | not stated | 0.5 mm | not stated | not stated | ScopeStuff database lists all these Orion accessory screws as M3-.5 | Confirmed |
Fitment records and sources
ScopeStuff database lists all these Orion accessory screws as M3-.5
pitch 0.5 mm · tap 2.5 mm · clearance 3.4 mm · PH1 / Torx T10
How to check the screw before you buy
- VESA holes are threaded inserts in the back cover; if a screw stops early, back it out rather than forcing it, because a bottomed-out screw can crack the panel housing.
- Diameter: across the threads an M3 screw measures about 3 mm with calipers (usually a hair under). If yours measures noticeably more or less, it is a different thread.
- Pitch: 0.5 mm from one thread crest to the next (20 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 M3 heads take PH1 for Phillips and T10 for Torx, and a 2.5 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 M3 is about 80-130 N·cm into metal threads and 35-60 N·cm into plastic bosses; snug it up and stop.
Common mix-ups with M3
- Telescope thumbscrews are sold in a wide non-metric legacy range too (1/4-20, 8-32, 10-32 on many Meade/Celestron mounts), so metric M3/M4 fitment applies mainly to newer/international accessory ecosystems (SkyWatcher, generic 1.25" accessories) and should not be assumed universal.
- GoPro's own official Dive Housing user guide does not itself state a metric screw size for the housing body; only third-party accessory manufacturer (INON) manuals explicitly cite M6 screws for their add-on arms/adapters attaching to the housing.
More in Displays, TVs & Mounts
The same screw also fits
Devices whose records share a thread with Orion Barlows/diagonal/finder screws (2x Deluxe Baffled Barlow 1997, 2x Ultrascopic Barlow 1999, 45-degree Erect-Image Diagonal 1999, 5x finder 3-point adjust 1997), closest length match first.
- Dell U2212H also M3
- Dell P1913 also M3
- Dell P2720D also M3
- Dell U2713H also M3
- Dell P2219HC also M3
- Dell P2720DC also M3
- Sonos One mid-woofer also M3
- LED strip mounting clips also M3
Questions about Orion Barlows/diagonal/finder screws (2x Deluxe Baffled Barlow 1997, 2x Ultrascopic Barlow 1999, 45-degree Erect-Image Diagonal 1999, 5x finder 3-point adjust 1997) screws
- What size screw does Orion Barlows/diagonal/finder screws (2x Deluxe Baffled Barlow 1997, 2x Ultrascopic Barlow 1999, 45-degree Erect-Image Diagonal 1999, 5x finder 3-point adjust 1997) use?
- M3 for scopeStuff database lists all these Orion accessory screws as M3-.5.
- How long are the screws in Orion Barlows/diagonal/finder screws (2x Deluxe Baffled Barlow 1997, 2x Ultrascopic Barlow 1999, 45-degree Erect-Image Diagonal 1999, 5x finder 3-point adjust 1997)?
- 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 M3 screw?
- 0.5 mm (coarse), which is the standard pitch for M3 machine screws; a 0.35 mm fine pitch exists but is uncommon. The tap drill is 2.5 mm and the normal clearance hole is 3.4 mm.
- What screwdriver do I need for Orion Barlows/diagonal/finder screws (2x Deluxe Baffled Barlow 1997, 2x Ultrascopic Barlow 1999, 45-degree Erect-Image Diagonal 1999, 5x finder 3-point adjust 1997)?
- The sources do not name the drive. For M3, Phillips heads normally take PH1 and Torx heads T10; socket heads take a 2.5 mm hex key.
- Can I use an imperial screw instead of M3?
- No. Imperial look-alike: #5-40 (3.18 mm) or #4-40 — neither interchanges with M3. Use a true M3 screw so it does not cross-thread or strip the hole.