# Split key rings 1/2 to 1-1/4 in: outside diameter, inside diameter and wire diameter (Key Ring maker table)

> What is the actual outside diameter and wire diameter of a 1 inch split key ring?

- Category: Mechanisms › Mechanism parts
- Kind: Standard part
- Basis: four keyring.com product pages (actual dimensions per nominal size); numbers only. mm values are the inch figures × 25.4
- Page: https://xemstudio.com/objects/split-key-rings/ · JSON: https://xemstudio.com/api/geometry?object=split-key-rings · Plain text: https://xemstudio.com/objects/split-key-rings/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

**Exact dimensions.** True size, with no tolerance added.

## Notes

- A split key ring is sold by a nominal diameter ('1 in'), which is approximate: keyring.com's actual figures are, for the stainless 1 in ring, outside diameter 1.100 in, inside diameter 0.932 in, wire diameter 0.072 in; for the 1/2 in stainless ring 0.670 / 0.510 / 0.050 in. Its pages also print dimensions called A and B for each ring (A .070 to .090 in, B .105 to .130 in); the pages do not define A and B, so the meanings are not given here.
- Different materials and origins of the same nominal size differ: the 3/4 in solid-brass ring is 0.875 in outside diameter and the 3/4 in stainless ring is listed at 0.880 in (its other dimensions are not printed). One page lists the 1-1/4 in ring as 'approximately 33 mm' outside diameter, against 1.255 in (31.9 mm) in its table; the table values are used. The 1 in nickel-plated and the 1-1/2 and 2 in rings are listed without dimensions in the pages read, and a retailer page for a 2 in Lucky Line ring gives only '2 in diameter' without saying outside or inside, so none of these is tabulated.
- S-hooks and other closed ring types were not tabulated: no maker table with wire diameter and opening was read. A split ring is two turns of wire; the turn spacing is not defined by the numbers published, so no ring is drawn.
- No file. McMaster-Carr lists split rings and tag rings with per-part CAD; linked, not copied. Ball chain, which also ends in a split ring or connector: ball-chain-sizes.

## Sizes

| ring | nominal | outside diameter | inside diameter | wire diameter | A / B (as printed) |
|---|---|---|---|---|---|
| stainless steel, USA (type 304, spring tempered) | 1/2 in | .670 in (17.02 mm) | .510 in (12.95 mm) | .050 in (1.27 mm) | .070 / .105 in |
| solid brass, USA | 3/4 in | .875 in (22.22 mm) | .707 in (17.96 mm) | .072 in (1.83 mm) | .084 / .110 in |
| stainless steel, USA | 1 in | 1.100 in (27.94 mm) | .932 in (23.67 mm) | .072 in (1.83 mm) | .084 / .110 in |
| nickel plated, China | 1-1/4 in | 1.255 in (31.88 mm) | 1.060 in (26.92 mm) | .090 in (2.29 mm) | .090 / .130 in |

## Where the files are

- Key Ring (keyring.com): [Split key rings: stainless 1/2 in USA, solid brass 3/4 in USA, stainless 1 in USA, nickel plated 1-1/4 in (China): outside / inside / wire diameter, A and B dimensions](https://www.keyring.com/stainless-steel-split-keyring-1_2-diameter-usa.aspx) — web — Maker page; numbers only
- Key Ring (keyring.com): [Solid brass split key ring 3/4 in (USA), actual dimensions](https://keyring.com/solid-brass-split-key-ring-3-4-inch-diameter-usa) — web — Maker page; numbers only
- Key Ring (keyring.com): [Stainless steel split key ring 1 in (USA)](https://keyring.com/stainlesssteelsplitkeyring1diameterusa.aspx) — web — Maker page; numbers only
- Key Ring (keyring.com): [Split key ring 1-1/4 in nickel plated (China)](https://keyring.com/split-key-ring-1-1-4-inch-diameter-nickel-plated-china) — web — Maker page; numbers only
- McMaster-Carr: [Split key rings and tag rings (free STEP/IGES per part, for your own design use; no redistribution)](https://www.mcmaster.com/chain/tag-rings-6) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution (verify at link)

## Questions

**What is the outside diameter of a 1 in split key ring?**

1.100 in (27.9 mm) for keyring.com's stainless 1 in ring, inside diameter 0.932 in (23.7 mm), wire 0.072 in (1.83 mm). The nominal 1 in is approximate.

**What is the wire diameter of a 1/2 in split ring?**

0.050 in (1.27 mm) for keyring.com's stainless 1/2 in ring (outside diameter 0.670 in, inside 0.510 in).

## Fits with

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