# Wing screws, inch (type A, cold formed, ASME B18.17 family): #8 to 3/8 in wing spread, height, thickness, boss

> How wide is a 1/4-20 wing screw, and how tall are its wings?

- Category: Hardware › Fasteners
- Kind: Standard part
- Basis: CDE Fasteners' type A wing screw sheet (ASME B18.6.8-2010 as printed) cross-checked with Tanner Bolt's cold-forged wing nut sheet (ASME B18.17), whose wing and boss dimensions are the same for the shared sizes; numbers only
- Page: https://xemstudio.com/objects/wing-screws-inch-asme-b18-17/ · JSON: https://xemstudio.com/api/geometry?object=wing-screws-inch-asme-b18-17 · Plain text: https://xemstudio.com/objects/wing-screws-inch-asme-b18-17/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

- Inches (max / min in each cell; the last column converts the maxima of A and B to mm). Sizes #8 to 3/8 in. A wing spread, B wing height, C wing thickness, E boss diameter, G boss height. CDE prints the wing screw table under ASME B18.6.8-2010 (type A: a two-piece screw, cold-formed winged head permanently installed on the shank) and gives length tolerances by nominal length: ±0.03 in up to 1 in, ±0.06 over 1 to 2 in, ±0.09 over 2 in. No lengths are listed on that sheet.
- Cross-check: Tanner's cold-forged wing nut sheet (the ASME B18.17 table, already tabulated on wing-nuts-din-315-asme-b18-17) prints identical A, B, C, E and G max / min for #8, #10, 1/4, 5/16 and 3/8 (e.g. 1/4: A 1.10 / 0.97, B 0.57 / 0.43, C 0.18 / 0.14, E 0.50 / 0.45, G 0.22 / 0.17). The dimension D (between the wings), printed for wing nuts, is not on the wing screw sheet and is not shown. Types B and C (other head forms) were not found with numbers.
- No files: the wing outline (curve, cross-section) is not published as numbers in any table read, so no model is drawn. Metric forms: wing-screws-din-316. McMaster-Carr sells wing screws with per-part STEP; linked, not copied.

## Sizes

| size | TPI | A wing spread (in) | B wing height (in) | C wing thickness (in) | E boss diameter (in) | G boss height (in) | mm (max) |
|---|---|---|---|---|---|---|---|
| #8 | 32 | 0.91 / 0.78 | 0.47 / 0.34 | 0.14 / 0.10 | 0.43 / 0.39 | 0.18 / 0.14 | A 23.1 mm, B 11.9 mm |
| #10 | 24 & 32 | 0.91 / 0.78 | 0.47 / 0.34 | 0.14 / 0.10 | 0.43 / 0.39 | 0.18 / 0.14 | A 23.1 mm, B 11.9 mm |
| 1/4 | 20 | 1.10 / 0.97 | 0.57 / 0.43 | 0.18 / 0.14 | 0.50 / 0.45 | 0.22 / 0.17 | A 27.9 mm, B 14.5 mm |
| 5/16 | 18 | 1.25 / 1.12 | 0.66 / 0.53 | 0.21 / 0.17 | 0.58 / 0.51 | 0.25 / 0.20 | A 31.8 mm, B 16.8 mm |
| 3/8 | 16 | 1.44 / 1.31 | 0.79 / 0.65 | 0.24 / 0.20 | 0.70 / 0.64 | 0.30 / 0.26 | A 36.6 mm, B 20.1 mm |

## Where the files are

- CDE Fasteners: [Wing screws type A, cold formed (sheet cites ASME B18.6.8-2010): wing spread A, height B, thickness C, boss E and G max / min, sizes 8 to 3/8](https://cdefasteners.com/sites/default/files/product-specs/wingscrtypea.pdf) — web — Maker datasheet; numbers only
- Tanner Bolt (wing nut sheet, ASME B18.17): [Cold-forged wing nuts: A, B, C, D, E, G (cross-check of the shared wing and boss dimensions)](https://www.tannerbolt.com/media/akeneo_connector/Nutsforgedwing.pdf) — web — Maker datasheet; numbers only
- McMaster-Carr: [Wing screws (category)](https://www.mcmaster.com/wing-screws/) — web, STEP — McMaster-Carr site terms: personal design use, no redistribution (verify at link)

## Questions

**How wide is a 1/4-20 wing screw?**

Wing spread A is 1.10 in max / 0.97 in min (27.9 / 24.6 mm), wing height B 0.57 / 0.43 in (CDE sheet).

**What are the boss dimensions of a #10 wing screw?**

Boss E 0.43 / 0.39 in, boss height G 0.18 / 0.14 in.

**Are wing screws and wing nuts the same wing size?**

Yes for the shared sizes: A, B, C, E and G match between CDE's wing screw sheet and Tanner's ASME B18.17 wing nut sheet.

## Fits with

- [Wing screws, DIN 316 (round wings, German form), M4–M24: boss, wing span, height and nominal lengths](https://xemstudio.com/objects/wing-screws-din-316/)
- [Wing nuts: DIN 315 M4–M24 and ASME B18.17 #4 to 3/4 — boss, wing spread, height, wing thickness](https://xemstudio.com/objects/wing-nuts-din-315-asme-b18-17/)
- [Knurled thumb screws, low type (DIN 653), M1–M10: head diameter, head height, shank, nominal lengths + 6 models](https://xemstudio.com/objects/thumb-screws-din-653-low-type/)
- [Knurled thumb screws, high type (DIN 464), M2–M10: head diameter, head height, shank, thread length, slot](https://xemstudio.com/objects/knurled-thumb-screws-din-464/)
- [Imperial machine screws: #4-40, #6-32, #8-32, 1/4-20](https://xemstudio.com/objects/imperial-machine-screws/)
- [Star knobs, DIN 6336 (cast iron), Ø32–80: thread, bore, height and depth](https://xemstudio.com/objects/star-knobs-din-6336/)