AISC 360
The governing specification for designing structural steel buildings in the U.S.
Quick Answer
AISC 360, the Specification for Structural Steel Buildings, is published by the American Institute of Steel Construction and sets design requirements for steel members and connections. It supports both load and resistance factor design (LRFD) and allowable strength design (ASD), and the International Building Code references it for steel buildings.
The Full Picture
AISC 360 is the main U.S. specification for designing structural steel buildings. It is developed by the American Institute of Steel Construction through a consensus committee, and the IBC adopts specific editions by reference, which makes it enforceable wherever that code applies.
The specification covers general design requirements, stability, and the design of tension members, compression members, beams, and composite members, as well as connections, fabrication, erection, and quality control provisions. It allows two design philosophies: LRFD, which compares factored loads to factored strength, and ASD, which compares service-level demands to allowable strengths.
AISC 360 works within a family of related documents. AISC 341 addresses seismic provisions for steel structures, AISC 303 is the Code of Standard Practice that defines roles and responsibilities among owner, designer, fabricator, and erector, and the AISC Steel Construction Manual packages the specification with design aids. Loads still come from ASCE 7.
For preconstruction teams, steel design choices influence tonnage, connection complexity, fireproofing, and erection sequencing, all of which affect estimates. Structural drawings and specifications typically reference AISC documents, and the Code of Standard Practice is a useful reference for understanding what is included in a fabricator's scope.
Real Examples
Common Misconceptions
People assume: AISC 360 is the only document governing steel buildings.
Actually: It works with ASCE 7 for loads, AISC 341 for seismic systems, and the Code of Standard Practice for project roles and practices.
People assume: LRFD and ASD produce wildly different safety levels.
Actually: Both are intended to provide comparable reliability when used consistently. The difference is how loads and resistances are factored.
Does MeltPlan Solve This?
Partially — adjacentMeltPlan Code can help teams research steel-related code requirements and surface potential compliance questions. It does not design steel members or connections, which remain the engineer's responsibility. MeltPlan Takeoff can quantify steel from the drawings.
Research steel code requirements →Frequently Asked Questions
What does AISC 360 cover?
Design of steel members and connections, stability, composite construction, and related fabrication, erection, and quality provisions for structural steel buildings.
What is the difference between LRFD and ASD?
LRFD applies load factors and resistance factors for strength limit states. ASD compares service loads to allowable strengths that include a safety factor. Both are allowed under AISC 360.
How does AISC 360 relate to the IBC?
The IBC references a specific edition of AISC 360 for structural steel design, making it part of code compliance where the IBC is adopted.
What is AISC 341?
The AISC standard for seismic provisions for structural steel buildings, used with AISC 360 for steel lateral systems in seismic regions.