# Camera and mic mounts: ISO 518 cold shoe (18.6 mm), Arca-Swiss dovetail (38 mm, 45 degrees), 5/8-27 mic-stand thread + thread files

> How wide is a cold shoe and an Arca-Swiss dovetail, and what is the 5/8-27 microphone stand thread?

- Category: Hardware › Mounting standards
- Kind: Standard part
- Basis: Wikipedia's hot-shoe article and the ISO 518:2006 sample pages for the shoe; Acratech, RRS, Kasson, Leofoto and AstroPix for the dovetail width; Musicalhow for the mic thread; two thread files at the Unified basic profile
- Page: https://xemstudio.com/objects/camera-mic-mounts-cold-shoe-arca-5-8-27/ · JSON: https://xemstudio.com/api/geometry?object=camera-mic-mounts-cold-shoe-arca-5-8-27 · Plain text: https://xemstudio.com/objects/camera-mic-mounts-cold-shoe-arca-5-8-27/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files Xem Studio Design License (free to use and sell from, not to redistribute as files: https://xemstudio.com/license/)
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

## Overall (mm)

| length | width | height |
|---|---|---|
| 19.88 | 19.88 | 7.53 |

**Exact dimensions.** Every file is drawn at true size with no tolerance added. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your process's clearance before making the part.

## Notes

- ISO 518 (accessory shoe): the standard's basic dimensions are in Figures 1 and 2, which are images in the paywalled standard, so the shoe profile is not drawn. What is readable is the internal size 18.6 (+0.2/-0) x 16.0 (+3/-2) x 2 (+0.15/-0) mm, the 12.5 mm tooth spacing (Wikipedia) and the clearance areas A, B and C and the Ø5 mm contact (sample pages of the standard). A 'cold shoe' is the same mechanical shoe without the centre contact.
- Arca-Swiss style dovetail: width 38 mm and a 45 degree flank are what the sources agree on. Depth and tolerance are not published, makers' plates measure 38.0 to 38.75 mm (AstroPix), and clamps accept a range; RRS gives a 35 mm base. A fully dimensioned dovetail profile is therefore not available and no profile file is drawn; use your clamp's jaw width and test-fit.
- 5/8-27 microphone-stand thread: 5/8 in major diameter, 27 threads per inch, described as a unified special thread. Pitch is 25.4 / 27 = 0.9407 mm and the files are drawn at the Unified 60 degree basic profile (H = 0.866025 P, crest flat P/8, root flat P/4), the same method as the lens-thread files. No class or limits for the 5/8-27 were found, so the files are the maximum-material basic shape; add your process allowance on the flanks. The male ring has a bore of Ø10.86 mm and the female ring an outside Ø19.88 mm (wall 2 mm is a design choice); both are 8 turns long.
- Left out: the NATO accessory rail (STANAG 4694) because no page with its dimensions could be read; Picatinny / MIL-STD-1913 is on picatinny-rail-mil-std-1913. Microphone stand adapters between 5/8-27 and 3/8-16 exist (Musicalhow, retailers); their dimensions were not tabulated.
- Maker CAD: Really Right Stuff, Leofoto and Neutrik publish drawings per product; none of the pages read carried a rail or shoe drawing as numbers, so none is linked.

## Mating features (exact size; open press / slide / run / socket by your process clearance, leave designed and clamp as drawn)

| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| 5/8-27 external thread (file mic-thread-5-8-27-male-ring) | major Ø15.875, pitch Ø15.264, minor Ø14.857 mm, pitch 0.9407 mm, Unified basic profile | 5/8-27 internal thread of a microphone clip, holder or adapter (file mic-thread-5-8-27-female-ring) | designed | mic-thread-5-8-27-male* |
| 5/8-27 internal thread (file mic-thread-5-8-27-female-ring) | minor Ø14.857, pitch Ø15.264, major Ø15.875 mm, pitch 0.9407 mm, Unified basic profile | 5/8-27 male thread on a mic stand or boom (file mic-thread-5-8-27-male-ring) | designed | mic-thread-5-8-27-female* |

## Sizes

| item | value as published | source | note |
|---|---|---|---|
| ISO 518 camera accessory shoe (cold shoe), internal size | 18.6 (+0.2/-0) x 16.0 (+3/-2) x 2 (+0.15/-0) mm | Wikipedia 'Hot shoe' (cites ISO 518:2006) | three dimensions in the order printed; the article does not name them |
| ISO 518, spacing between the two teeth | 12.5 (+0.4/-0) mm | Wikipedia 'Hot shoe' |  |
| ISO 518 clearance area A (rectangular, Figure 3) | 12.5 mm in front, 25.0 mm at the back of the shoe; 25.0 mm to the right and left of the centre; nothing higher than 2.0 mm above the top surface | ISO 518:2006 sample pages (iTeh) | text of the standard, not an image |
| ISO 518 clearance area B (circular) | diameter 30.0 mm | ISO 518:2006 sample pages |  |
| ISO 518 area C (foot insertion) | extends 25.0 mm from the back of the shoe, 20.0 mm wide | ISO 518:2006 sample pages |  |
| ISO 518 centre contact; insulation | contact surface Ø5 mm (Figure 1); insulation resistance not less than 30 MOhm at 0 to 40 C | ISO 518:2006 sample pages | the shoe's basic dimensions are in Figures 1 and 2, which are images |
| Arca-Swiss dovetail, plate width | 38 mm (1 1/2 in); 38.1 mm in two reader sources; Leofoto 'a consistent 38 mm (1.50 in) width' | Acratech, The Last Word, Leofoto, AstroPix | AstroPix measured plates at 38.0, 38.05, 38.1, 38.15 and 38.75 mm |
| Arca-Swiss dovetail, angle | 45 degrees | Acratech; RRS | stated as 'the Arca-Swiss style dovetail is 45 degrees' |
| RRS dovetail, base width | 35 mm (about 1.38 in) wide base | Really Right Stuff | RRS calls its product 'RRS 1.5 in Dovetail Standard'; the page does not say what 1.5 in measures, so it is not equated with the 38 mm width |
| Arca-Swiss dovetail, depth and tolerance | not published | RRS, Acratech, Kasson, photomacrography.net | readers describe depth as the distance between the dovetail faces' meeting lines but give no value |
| Microphone stand thread, large | 5/8-27 ('unified special thread'); major Ø 15.875 mm (5/8 in); pitch 25.4 / 27 = 0.9407 mm | Musicalhow (name); diameter and pitch from the designation | a reader measured an old stand at 0.622 in outside diameter (not used) |
| Microphone stand thread, small | 3/8-16; 1/4-20 on camera gear | Musicalhow | 3/8-16 and 1/4-20 bosses are on camera-thread-bosses-1-4-20 |
| 5/8-27 files (Xem-drawn) | major Ø15.875, pitch Ø15.264, minor Ø14.857, pitch 0.9407, 7.53 long | Unified basic profile (ISO 68-1 / ASME B1.1) | limits and class of the 5/8-27 are not published in the sources read; the files are the basic profile |

## Where the files are

- Wikipedia: [Hot shoe: ISO 518 internal dimensions 18.6 (+0.2/-0) x 16.0 (+3/-2) x 2 (+0.15/-0) mm; spacing between the two teeth 12.5 (+0.4/-0) mm](https://en.wikipedia.org/wiki/Hot_shoe) — web — CC BY-SA 4.0 (text); dimensions are facts
- iTeh Standards (ISO 518:2006 sample pages): [ISO 518:2006 camera accessory shoes: clearance areas A, B, C and contact in the text; Figure 1 and 2 dimensions are images](https://cdn.standards.iteh.ai/samples/36330/0f7a221b5b7647cc972f7403f522191a/ISO-518-2006.pdf) — web — Publisher's page; dimensions are facts
- Acratech: [Arca-Swiss vs Bogen / Manfrotto plates: Arca-Swiss style dovetail is 45 degrees, plate 1 1/2 in (38 mm) wide](https://www.acratech.net/blog/arca-swiss-vs-bogen-manfrotto-camera-plates/) — web — Publisher's page; dimensions are facts
- Really Right Stuff: [What is the RRS dovetail standard: 45 degree dovetail, 35 mm (about 1.38 in) wide base on most plates; no depth or tolerance given](https://kb.reallyrightstuff.com/knowledge/what-is-the-rrs-dovetail-standard-1) — web — Publisher's page; dimensions are facts
- The Last Word (Jim Kasson): [Plate width 38.1 mm (1.5 in) matched to RRS spec in a reader comment; no angle, depth or jaw dimensions given](https://blog.kasson.com/?p=24422) — web — Publisher's page; dimensions are facts
- Leofoto USA: [BPL series Arca-type rails: 'a consistent 38mm (1.50 in) width'](https://leofotousa.com/products/leofoto-bpl-series-arca-type-double-dovetail-rails) — web — Publisher's page; dimensions are facts
- AstroPix: [Dovetail sizes: Arca-Swiss 38 mm, measured plates 38.0 to 38.75 mm](https://astropix.com/wp/dovetail-sizes) — web — Publisher's page; dimensions are facts
- Musicalhow: [Microphone stand thread sizes: 5/8-27 unified special thread, 3/8-16, 1/4-20](https://www.musicalhow.com/microphone-stand-thread-sizes/) — web — Publisher's page; dimensions are facts
- Bureau of Indian Standards (via Public.Resource.Org): [IS 4218 (Part 1):2001 ISO general purpose metric screw threads, basic profile (identical with ISO 68-1:1998): H = 0.866025404 P, 5H/8 = 0.541265877 P, 3H/8 = 0.324759526 P](https://law.resource.org/pub/in/bis/S01/is.4218.1.2001.pdf) — web — Public.Resource.Org (public law); dimensions are facts
- Wikipedia: [Unified Thread Standard (ASME B1.1): same 60 degree basic profile as ISO 68-1](https://en.wikipedia.org/wiki/Unified_Thread_Standard) — web — CC BY-SA 4.0 (text); dimensions are facts

## Free STEP/STL (2 parts, Xem Studio Design License, Xem Studio)

Index: https://xemstudio.com/files/hardware/camera-mic-mounts-cold-shoe-arca-5-8-27/index.json · license: https://xemstudio.com/files/hardware/camera-mic-mounts-cold-shoe-arca-5-8-27/LICENSE.md

- mic-thread-5-8-27-male-ring: [STEP](https://xemstudio.com/files/hardware/camera-mic-mounts-cold-shoe-arca-5-8-27/mic-thread-5-8-27-male-ring.step) · [STL](https://xemstudio.com/files/hardware/camera-mic-mounts-cold-shoe-arca-5-8-27/mic-thread-5-8-27-male-ring.stl) — 5/8-27 UN external thread ring section (microphone-stand thread): Unified basic profile, major Ø15.875, pitch Ø15.264, minor Ø14.857, pitch 0.9407; 7.53 long (8 turns), bore Ø10.857 (wall is a design choice); exact nominal, no tolerance
- mic-thread-5-8-27-female-ring: [STEP](https://xemstudio.com/files/hardware/camera-mic-mounts-cold-shoe-arca-5-8-27/mic-thread-5-8-27-female-ring.step) · [STL](https://xemstudio.com/files/hardware/camera-mic-mounts-cold-shoe-arca-5-8-27/mic-thread-5-8-27-female-ring.stl) — 5/8-27 UN internal thread ring section (microphone clip / holder thread): Unified basic profile, minor Ø14.857, pitch Ø15.264, major Ø15.875, pitch 0.9407; 7.53 long (8 turns), outside Ø19.875 (design choice); exact nominal, no tolerance

## Questions

**How wide is a cold shoe?**

ISO 518 (via Wikipedia): the internal size is 18.6 (+0.2/-0) x 16.0 (+3/-2) x 2 (+0.15/-0) mm, tooth spacing 12.5 mm.

**How wide is an Arca-Swiss plate?**

38 mm (1 1/2 in) with a 45 degree dovetail; plates measure 38.0 to 38.75 mm in practice and RRS gives a 35 mm base. Depth is not published.

**What is the 5/8-27 thread?**

The large microphone-stand thread: 5/8 in (15.875 mm) major diameter, 27 threads per inch (0.9407 mm pitch); a unified special thread. The files draw it at the Unified basic profile.

## Fits with

- [Camera tripod thread bosses: 1/4-20 UNC and 3/8-16 UNC](https://xemstudio.com/objects/camera-thread-bosses-1-4-20/)
- [Lens filter threads: M40.5 × 0.5 to M112, pitch table and thread rings](https://xemstudio.com/objects/lens-filter-threads/)
- [Picatinny rail (MIL-STD-1913): profile, grooves and mount jaw](https://xemstudio.com/objects/picatinny-rail-mil-std-1913/)
- [Scope dovetail rails: 11 mm (European) and 3/8 in (US), and Weaver](https://xemstudio.com/objects/scope-dovetail-rails/)
- [DJI Mic 3 transmitter (DMT03)](https://xemstudio.com/objects/dji-mic-3-transmitter/)
- [RODE PodMic](https://xemstudio.com/objects/rode-podmic/)
- [VESA mount hole patterns: 75, 100, 200×100, 200×200, 400×200, 400×400, 600×400, 800×400](https://xemstudio.com/objects/vesa-mount-patterns/)