Flat washers, inch: SAE and USS, 1/4 to 3/4 in (ASME B18.21.1 Type A) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/flat-washers-inch/  (CC BY 4.0)
Basis: ASME B18.21.1 Type A plain washers, narrow (SAE) and wide (USS): ID, OD, thickness (nominal)
Catalog version: 2026-10-20

Sizes: see table below
- SAE washers are narrow (fit under socket heads and in tight spots); USS are wide (spread load on wood and soft material).

size  type  id_in  od_in  thickness_in
1/4  USS  0.312  0.734  0.065
1/4  SAE  0.281  0.625  0.065
5/16  USS  0.375  0.875  0.083
5/16  SAE  0.344  0.688  0.065
3/8  USS  0.438  1.0  0.083
3/8  SAE  0.406  0.812  0.065
7/16  USS  0.5  1.25  0.083
7/16  SAE  0.469  0.922  0.065
1/2  USS  0.562  1.375  0.109
1/2  SAE  0.531  1.062  0.095
5/8  USS  0.688  1.75  0.134
5/8  SAE  0.656  1.312  0.095
3/4  USS  0.812  2.0  0.148
3/4  SAE  0.812  1.469  0.134

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- ASME: ASME B18.21.1 Washers: helical spring-lock, tooth lock, and plain washers (inch) — standard — ASME; dimensions are facts [verify license at link] — https://www.asme.org/codes-standards/find-codes-standards/b18-21-1-washers-helical-spring-lock-tooth-lock-plain-washers-(inch-series)

Free files (CC BY 4.0, Xem Studio; STEP + STL, 14 parts): https://xemstudio.com/files/hardware/flat-washers-inch/index.json
API: https://xemstudio.com/api/geometry?object=flat-washers-inch