Axial fans, 25 to 140 mm: frames and hole patterns — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/axial-fan-frames/  (CC BY 4.0)
Basis: Industry-standard square axial fan frames (hole pattern = frame − 8 mm for 40 mm and larger except 140, which uses 124.5)
Catalog version: 2026-10-20

Sizes: see table below
- Hole patterns: 25→20, 30→24, 40→32, 50→40, 60→50, 70→61.5, 80→71.5, 92→82.5, 120→105, 140→124.5 mm. Holes Ø4.3 from 50 mm up, Ø3.5 (M3) for 40 and Ø2.9 (M2.5) for 25/30.
- Thickness: 10 mm for 25–40, 15 for 50–70, 25 for 80–140 (15 mm slim 120s exist; 4020 is a 20 mm 40). Airflow arrows are moulded on the frame side.
- Print a grille/duct to the frame outer size + 0.5 mm; the files are the frame envelope with a solid hub so the duct can be checked for clearance.

frame_mm  hole_pattern_mm  hole_dia_mm  thickness_mm
25  20  2.9  10
30  24  2.9  10
40  32  3.5  10
50  40  4.3  15
60  50  4.3  15
70  61.5  4.3  15
80  71.5  4.3  25
92  82.5  4.3  25
120  105  4.3  25
140  124.5  4.3  25

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Wikipedia: Computer fan — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Computer_fan
- McMaster-Carr: Equipment-cooling fans (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/equipment-cooling-fans/

Free files (CC BY 4.0, Xem Studio; STEP + STL, 12 parts): https://xemstudio.com/files/hardware/axial-fan-frames/index.json
API: https://xemstudio.com/api/geometry?object=axial-fan-frames