October 22, 2026
Thought Leadership
Three Things in the AISC 360-27 Draft Worth a Fabricator's Attention
AISC has the next edition of the Specification for Structural SteelBuildings out for public review until 26 October, and threethings in it matter to fabricators.
The first is a new category of connection called a strain sensitivedetail. It covers heavy welded joints in tension where a cope, an access holeor a discontinuous member interrupts the section between intersecting completejoint penetration welds. The engineer identifies them in the contractdocuments, and once identified they carry a set of extra requirements. Plateordered with additional toughness testing. Extra steps at the cut and at theweld. An inspection after erection.
This is a term to watch for in future contracts. It is worthbuilding into your contract review, because the requirements reach intoprocurement, the shop and the inspection program. If they are missed, they arean expensive miss.
The second is that a good deal of the draft codifies practice thatalready lives in shops. Reentrant corner radii. Heat limits for cambering andstraightening. What gets ground before galvanizing, and what should not begalvanized at all.
Most shops do all of this already. What changes is that the writtenversion becomes the one that counts, and that creates an audit job. Housestandards, cope macros, radius libraries and saved programs should match butmight not. Worth double checking before it becomes a compliance problem.
The third is a new option on how welds get sampled for testing.Where the required testing rate is below 100 percent, the draft lets the pool asample is drawn from be defined by the conditions welds were produced under,across jobs, rather than project by project. A user note points directly atshop variables like shift and weld process as the more meaningful thing toassess against.
Every certified shop already holds the weld data this relies on.What it does not usually hold is that data cut by shift, process or cell acrossa rolling period, because QC records are filed by job and the job file is whataudits ask for. The same records organized a second way turn into an argumentfor a lower testing rate. The other half is timing, since this has to be agreedwith the engineer of record before construction, which puts it at contractstage rather than in the middle of a job. It might be time to review how yourweld data is organized so if you wanted to use this option in the future, youcan.
Underneath all three is the same direction shift. The specificationis describing more of what happens where pieces meet, and less about the piecesthemselves. That makes connections even more important.
A new connection type to watch for, a practice audit to run, and a samplingoption to raise are the key takeaways. The comment window closes on 26 October.
