Loading…
1
Foreman swore by the 1/8" rule for steel, cost us a full rework in Phoenix
Old timer told me to always add 1/8 inch to every steel dimension for expansion, but the actual spec sheet from the fabricator said 3/16 and we had to cut 14 brackets down on site, has anyone else had a shop override an old school habit?
1 comments
Log in to join the discussion
Log In1 Comment
ray_hernandez1mo ago
Read a metallurgy study a few years back that basically said thermal expansion on carbon steel is way more complicated than a flat number. The temp swing, the length of the piece, and the ambient humidity all change it. That old rule probably worked fine in a cooler shop, but Phoenix heat does weird stuff to metal before you even bolt it down. Had a similar deal on a gate job where the welder swore by the same rule, and we ended up shimming everything. The fabricator's spec sheet is the only thing you can really hang your hat on, because that's what they built to. Those 14 brackets should've been cut by the shop, not on site, but the foreman wanted to save face. Next time, make them put the tolerance on the drawing in writing before it leaves the plant.
2