Threaded standoffs, M2.5 and M3 (hex and round) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/threaded-standoffs-metric/  (CC BY 4.0)
Basis: common vendor dimensions
Catalog version: 2026-10-20

Sizes: see table below
- M2.5 (Raspberry Pi) standoffs: 5 mm across flats; M3: 5.5 mm across flats. Lengths 3–40 mm in 1–5 mm steps; male-female adds a 6 mm stud.
- Pocket for a hex standoff in a print: AF + 0.2 mm.

thread  width_af_mm  corner_mm  common_lengths_mm
M2.5  5  5.8  3, 5, 6, 8, 10, 12, 15, 20
M3  5.5  6.4  5, 6, 8, 10, 12, 15, 20, 25, 30

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- McMaster-Carr: Standoffs (free STEP/IGES/STL per part, for your own design use; no redistribution) — STEP, IGES, STL, PDF — McMaster-Carr site terms: personal design use, no redistribution [verify license at link] — https://www.mcmaster.com/products/standoffs/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 16 parts): https://xemstudio.com/files/hardware/threaded-standoffs-metric/index.json
API: https://xemstudio.com/api/geometry?object=threaded-standoffs-metric