Strut U fittings, Z fittings and post bases, 1-5/8 in: B116-12 U-support — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/strut-u-z-fittings-post-bases/  (sheet CC BY 4.0)
Basis: Distributor listing of B-Line B116-12ZN; leg and hole drawings could not be read, numbers only, no file
Catalog version: 2026-10-20

Sizes: see table below
- Listed: 3 holes, 5-7/16 in long, 1-5/8 in wide, 1/4 in thick, 9/16 in holes, depth 2-7/16 in (the listing's own label; the listing also contradicts itself on width, so treat as unconfirmed).
- Z fittings and post bases (B279, B280, B281A families) show 3/4 in holes in the catalog, but the hole pattern per part number could not be matched, so nothing is published.

part  holes  length  width  depth  thickness  hole
B116-12  3  5-7/16 in (138.1 mm)  1-5/8 in (41.3 mm)  2-7/16 in (61.9 mm)  1/4 in (6.4 mm)  9/16 in (14.3 mm)

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Eaton B-Line: B-Line series strut systems: Strut fittings catalog section (flat plate, 90° angle, U, Z fittings, post bases) — web — Publisher's page; dimensions are facts — https://www.eaton.com/content/dam/eaton/products/support-systems/strut-systems-&-accessories/strut-fittings-and-accessories/strut-fittings-catalog-section.pdf
- Steiner Electric (distributor): B-Line B116-12ZN 3-hole U-support: 5-7/16 in long, 1-5/8 in wide, 1/4 in — web — Publisher's page; dimensions are facts — https://steinerelectric.com/Catalog/ConduitFittings-And-Wireway/Cable-Trays-And-Struts/Strut-Channels-And-Accessories/Channel-U-Shaped-Fittings/B-Line-B116-12ZN-3-Hole-U-Support5-7-16-in-L-x-1-5-8-in-W-x-1-4-in-THKSteel-218807
- McMaster-Carr: Strut channel fittings (free STEP/IGES per part, for your own design use; no redistribution) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution [verify license at link] — https://www.mcmaster.com/products/strut-channel-fittings/

No true-size file yet: the published figures do not fix the whole shape; a measured scan is planned.
API: https://xemstudio.com/api/geometry?object=strut-u-z-fittings-post-bases