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Camera tripod thread bosses: 1/4-20 UNC and 3/8-16 UNC
What thread is a camera tripod screw? · Hardware · basis: DIN 4503-1 / ISO 1222 tripod threads as given by Threading Tools Guide: 1/4-20 UNC (major Ø6.35, core hole Ø5.35) and 3/8-16 UNC (major Ø9.52, core hole Ø8.25)
Exact dimensions. Every file is drawn at true size with no printing tolerance. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your printer's or process's clearance before making the part. Mating features
- sizes
- 2 in table
Notes
- Cameras, phone clamps, lights and small tripod heads take a 1/4-20 UNC screw; larger heads and most tripod-to-head joints use 3/8-16 UNC. Both are 60° Unified threads.
- Files: a round boss for each with a blind hole at the published core-hole diameter, to cut the internal thread into or to fit a threaded insert of your choice. The boss Ø, height and hole depth are my design.
- The screw side is in the catalog: 1/4-20 socket head cap screws in imperial-machine-screws.
- Arca-Swiss style dovetails are not drawn: there is no published standard; makers' plates measure 38.0 to 38.75 mm across.
Sizes
| thread | major Ø (mm) | core hole Ø (mm) | boss (my design) | from |
|---|---|---|---|---|
| 1/4-20 UNC | 6.35 | 5.35 | Ø16 × 10, hole 8 deep | DIN 4503-1 / ISO 1222 (Threading Tools Guide) |
| 3/8-16 UNC | 9.52 | 8.25 | Ø22 × 12, hole 10 deep | DIN 4503-1 / ISO 1222 (Threading Tools Guide) |
Mating features
Drawn at the exact size. Open press, slide, run and socket features by your process's clearance; leave designed gaps and clamp fits as drawn.
| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| core hole | Ø5.35 (1/4-20 UNC) / Ø8.25 (3/8-16 UNC) | internal thread cut to the screw (DIN 4503-1 / ISO 1222) | designed | camera-boss-* |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| Threading Tools Guide | Tripod thread DIN 4503-1 / ISO 1222: 1/4-20 UNC (Ø6.35, core hole Ø5.35) and 3/8-16 UNC (Ø9.52, core hole Ø8.25) | web | reference verify |
Free files
★ Free files 2 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json
| camera-boss-1-4-20 | 1/4-20 UNC boss: Ø16 × 10 (my size), blind core hole Ø5.35 × 8 deep from the top face for the 1/4-20 UNC internal thread (major Ø6.35) | STEP · STL |
| camera-boss-3-8-16 | 3/8-16 UNC boss: Ø22 × 12 (my size), blind core hole Ø8.25 × 10 deep from the top face for the 3/8-16 UNC internal thread (major Ø9.52) | STEP · STL |
Plain text: sheet.txt · JSON: /api/geometry?object=camera-thread-bosses-1-4-20
How it fits
Goes in or on
Handlebar clamp ringsa boss unioned onto a bar clampConnects to
Imperial machine screws1/4-20 screw into the bossAlternatives
GoPro-style three-finger mountthree-finger action-camera mountYou might also need
Questions
What thread is a camera tripod screw?
1/4-20 UNC on cameras and small accessories, 3/8-16 UNC on larger heads and tripods (DIN 4503-1 / ISO 1222).
What hole size for a 1/4-20 thread?
Core hole Ø5.35 mm per DIN 4503-1 as given by Threading Tools Guide; the major diameter is 6.35 mm.
Is there a standard Arca-Swiss plate drawing?
No published standard; plates measure 38.0–38.75 mm across the dovetail, so none is drawn here.