Structural Steel Framing
Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
Showing changes from Rev 6
to Rev 7
in Structural Steel Framing.
---
title: Structural Steel Framing
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### Special inspection is required for the categories listed below under IBC 1705.2. {note}
+### The building's IBC Risk Category shall be specified, since it determines the scope and frequency of special inspection required for the structural steel.
+
```datasheet
label: IBC Risk Category
…97 unchanged lines
### QA inspection firms shall have no business, financial, or organizational relationship with the fabricator or erector.
−# Materials {toc}
+# Structural Shapes {toc}
−## Structural Shapes {toc}
+## Wide-Flange Shapes {toc}
−### Wide-Flange Shapes {toc}
−
```datasheet
label: Wide-Flange Shapes (W Sections)
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```
−#### ASTM A992 is the standard specification for wide-flange shapes in the United States and is used for essentially all W-section beams, girders, and columns in commercial construction. {note}
−#### A992 provides three critical properties that distinguish it from older specifications: a minimum yield-to-tensile ratio of Fu/Fy ≥ 1.18 (ensuring the material can strain-harden before fracture), a maximum yield-to-tensile ratio of Fy/Fu ≤ 0.85 (preventing shapes with extremely high, unpredictable yield strength), and a maximum carbon equivalent (CE ≤ 0.45 for Groups 1–3, ≤ 0.47 for Groups 4–5) to ensure reliable weldability. {note}
−#### These controls are essential for predictable connection behavior and for seismic performance. {note}
+### ASTM A992 is the standard specification for wide-flange shapes in the United States and is used for essentially all W-section beams, girders, and columns in commercial construction. {note}
+### A992 provides three critical properties that distinguish it from older specifications: a minimum yield-to-tensile ratio of Fu/Fy ≥ 1.18 (ensuring the material can strain-harden before fracture), a maximum yield-to-tensile ratio of Fy/Fu ≤ 0.85 (preventing shapes with extremely high, unpredictable yield strength), and a maximum carbon equivalent (CE ≤ 0.45 for Groups 1–3, ≤ 0.47 for Groups 4–5) to ensure reliable weldability. {note}
+### These controls are essential for predictable connection behavior and for seismic performance. {note}
−#### ASTM A36 and ASTM A572 Grade 50 W-shapes shall not be substituted for A992 shapes without the SER's written approval.
+### ASTM A36 and ASTM A572 Grade 50 W-shapes shall not be substituted for A992 shapes without the SER's written approval.
−#### ASTM A913 Grade 50 or 65 shapes, produced by the quenching and self-tempering (QST) process, are specified where heavy column sections (W14×257 and heavier or Group 4 and 5 shapes) require enhanced through-thickness toughness, where high seismic demands per AISC 341-22 require Charpy V-notch (CVN) toughness for demand-critical members, or where the structural engineer requires Grade 65 or 70 to reduce member size in heavily loaded columns.
+### ASTM A913 Grade 50 or 65 shapes, produced by the quenching and self-tempering (QST) process, are specified where heavy column sections (W14×257 and heavier or Group 4 and 5 shapes) require enhanced through-thickness toughness, where high seismic demands per AISC 341-22 require Charpy V-notch (CVN) toughness for demand-critical members, or where the structural engineer requires Grade 65 or 70 to reduce member size in heavily loaded columns.
−#### The quenching and self-tempering process achieves higher strength and toughness in large shapes without the penalty in weldability that normally accompanies high-strength steel. {note}
+### The quenching and self-tempering process achieves higher strength and toughness in large shapes without the penalty in weldability that normally accompanies high-strength steel. {note}
−### Hollow Structural Sections {toc}
+## Hollow Structural Sections {toc}
```datasheet
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```
−#### ASTM A500/A500M Grade C is the standard specification for cold-formed welded and seamless HSS (both rectangular and round). {note}
−#### Grade C provides 50 ksi minimum yield and is preferred over Grade B because Grade B offers no procurement cost advantage while providing lower strength. {note}
−#### One persistent issue with A500 is wall thickness tolerance: the standard permits wall thickness to be as much as 10% below the nominal dimension. {note}
+### ASTM A500/A500M Grade C is the standard specification for cold-formed welded and seamless HSS (both rectangular and round). {note}
+### Grade C provides 50 ksi minimum yield and is preferred over Grade B because Grade B offers no procurement cost advantage while providing lower strength. {note}
+### One persistent issue with A500 is wall thickness tolerance: the standard permits wall thickness to be as much as 10% below the nominal dimension. {note}
−#### In calculations for connection strength using A500 HSS — particularly for welded connections to HSS walls or for local wall yielding — designers and fabricators shall apply the appropriate thickness reduction factor (typically 0.93 of nominal) per AISC 360-22.
+### In calculations for connection strength using A500 HSS — particularly for welded connections to HSS walls or for local wall yielding — designers and fabricators shall apply the appropriate thickness reduction factor (typically 0.93 of nominal) per AISC 360-22.
−#### ASTM A1085 is recommended for concentrically braced frames, eccentrically braced frames, and other seismic applications per AISC 341-22 where HSS members serve as primary structural elements, and is also appropriate for architecturally exposed HSS where dimensional precision is required.
+### ASTM A1085 is recommended for concentrically braced frames, eccentrically braced frames, and other seismic applications per AISC 341-22 where HSS members serve as primary structural elements, and is also appropriate for architecturally exposed HSS where dimensional precision is required.
−#### ASTM A1085 closes the tolerance gap: wall thickness tolerance is tightened to −5% (not −10%), a maximum mass tolerance of −3.5% is added, and an upper bound on yield strength of 70 ksi is imposed; the tighter tolerances eliminate the need for the 0.93 wall thickness reduction factor and the bounded yield strength improves connection ductility prediction. {note}
+### ASTM A1085 closes the tolerance gap: wall thickness tolerance is tightened to −5% (not −10%), a maximum mass tolerance of −3.5% is added, and an upper bound on yield strength of 70 ksi is imposed; the tighter tolerances eliminate the need for the 0.93 wall thickness reduction factor and the bounded yield strength improves connection ductility prediction. {note}
−### Channels, Angles, and Tees {toc}
+## Channels, Angles, and Tees {toc}
```datasheet
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```
−#### ASTM A36 is the standard specification for channels, angles, and miscellaneous shapes used in secondary framing, bracing, and kicker connections. {note}
+### ASTM A36 is the standard specification for channels, angles, and miscellaneous shapes used in secondary framing, bracing, and kicker connections. {note}
−#### A572 Grade 50 shall be specified for channels, angles, and tees where secondary member sizes must be minimized or where the SER has noted specific higher-strength requirements on the drawings.
+### A572 Grade 50 shall be specified for channels, angles, and tees where secondary member sizes must be minimized or where the SER has noted specific higher-strength requirements on the drawings.
−## Plates and Bars {toc}
+# Plates and Bars {toc}
```datasheet
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```
−### ASTM A36 plate is the standard for shear tabs, gusset plates, stiffeners, column base plates, bearing plates, and similar connection elements. {note}
−### A36's relatively low yield strength is an intentional design choice for many connection configurations: a "softer" plate yields predictably before fracture and accommodates deformation demands that would be better handled at the plate than at the weld or bolt. {note}
+## ASTM A36 plate is the standard for shear tabs, gusset plates, stiffeners, column base plates, bearing plates, and similar connection elements. {note}
+## A36's relatively low yield strength is an intentional design choice for many connection configurations: a "softer" plate yields predictably before fracture and accommodates deformation demands that would be better handled at the plate than at the weld or bolt. {note}
−### A572 Grade 50 plate shall not be substituted for A36 connection plate without the SER's written approval, because the substitution can shift the failure mode of the connection and may not be conservative.
+## A572 Grade 50 plate shall not be substituted for A36 connection plate without the SER's written approval, because the substitution can shift the failure mode of the connection and may not be conservative.
−### The SER shall explicitly note on the contract drawings where higher-strength plate is required.
+## The SER shall explicitly note on the contract drawings where higher-strength plate is required.
−## High-Strength Bolts {toc}
+# High-Strength Bolts {toc}
```datasheet
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```
−### ASTM F3125 is the consolidated specification for high-strength structural bolts, which superseded the legacy ASTM A325 and A490 individual standards. {note}
−### Grade A325 (120 ksi minimum tensile strength for bolt diameters ≤1 in., 105 ksi for larger diameters) is the standard for the majority of structural steel connections in commercial buildings. {note}
−### Grade A490 (150 ksi minimum tensile strength) is specified where bolt count or gauge distances limit the number of fasteners that can fit in a connection and the higher bolt shear and tension capacity of A490 resolves the constraint. {note}
+## ASTM F3125 is the consolidated specification for high-strength structural bolts, which superseded the legacy ASTM A325 and A490 individual standards. {note}
+## Grade A325 (120 ksi minimum tensile strength for bolt diameters ≤1 in., 105 ksi for larger diameters) is the standard for the majority of structural steel connections in commercial buildings. {note}
+## Grade A490 (150 ksi minimum tensile strength) is specified where bolt count or gauge distances limit the number of fasteners that can fit in a connection and the higher bolt shear and tension capacity of A490 resolves the constraint. {note}
−### Grade A490 bolts shall not be galvanized; the hot-dip galvanizing process can induce hydrogen embrittlement in high-strength steel, and ASTM F3125 explicitly prohibits galvanizing of A490.
+## Grade A490 bolts shall not be galvanized; the hot-dip galvanizing process can induce hydrogen embrittlement in high-strength steel, and ASTM F3125 explicitly prohibits galvanizing of A490.
−### Plain (black) bolts shall be used on the majority of projects.
+## Plain (black) bolts shall be used on the majority of projects.
−### Galvanized bolts shall be used where the connected structural steel is hot-dip galvanized.
+## Galvanized bolts shall be used where the connected structural steel is hot-dip galvanized.
−### When galvanized bolts are specified, the bolts, nuts, and washers shall be from the same lot and shall be furnished as matched assemblies that have been rotational-capacity tested per RCSC 2020 Section 2.3.3.
+## When galvanized bolts are specified, the bolts, nuts, and washers shall be from the same lot and shall be furnished as matched assemblies that have been rotational-capacity tested per RCSC 2020 Section 2.3.3.
−### Galvanized nuts shall be overtapped to accommodate the zinc coating thickness; standard nuts shall not be used on galvanized bolts.
+## Galvanized nuts shall be overtapped to accommodate the zinc coating thickness; standard nuts shall not be used on galvanized bolts.
−## Anchor Rods {toc}
+# Anchor Rods {toc}
```datasheet
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```
−### ASTM F1554 is the standard specification for anchor rods and covers three yield strength grades. {note}
−### Grade 36 is the standard for column base plate anchor rods in most commercial buildings; it provides adequate strength for typical gravity and wind-driven overturning loads, is readily available, and is compatible with standard hook embedment configurations. {note}
−### Anchor rod sizes, diameters, embedment depths, projection lengths, spacing, and group locations are [[drawing: as indicated on the structural foundation plans and anchor rod setting plans]]. {note}
+## ASTM F1554 is the standard specification for anchor rods and covers three yield strength grades. {note}
+## Grade 36 is the standard for column base plate anchor rods in most commercial buildings; it provides adequate strength for typical gravity and wind-driven overturning loads, is readily available, and is compatible with standard hook embedment configurations. {note}
+## Anchor rod sizes, diameters, embedment depths, projection lengths, spacing, and group locations are [[drawing: as indicated on the structural foundation plans and anchor rod setting plans]]. {note}
−### Grade 55 anchor rods that must be welded shall be specified with the optional weldability supplement (Supplement S1); without the weldability supplement, Grade 55 is not reliably weldable.
+## Grade 55 anchor rods that must be welded shall be specified with the optional weldability supplement (Supplement S1); without the weldability supplement, Grade 55 is not reliably weldable.
−### Grade 105 anchor rods are used where high tensile demand, large diameter rods, or seismic overturning moments require higher strength, and shall not be used where 90-degree hooks are required because their high strength and hardness make them unsuitable for bending.
+## Grade 105 anchor rods are used where high tensile demand, large diameter rods, or seismic overturning moments require higher strength, and shall not be used where 90-degree hooks are required because their high strength and hardness make them unsuitable for bending.
−### Anchor rod grades shall be color-coded at the projecting end: blue for Grade 36, yellow for Grade 55, red for Grade 105.
+## Anchor rod grades shall be color-coded at the projecting end: blue for Grade 36, yellow for Grade 55, red for Grade 105.
−### Anchor rod placement templates shall be furnished by the fabricator and used by the concrete subcontractor when setting rods; see [[sync/cast-in-place-concrete]] for concrete placement and anchor rod tolerance requirements.
+## Anchor rod placement templates shall be furnished by the fabricator and used by the concrete subcontractor when setting rods; see [[sync/cast-in-place-concrete]] for concrete placement and anchor rod tolerance requirements.
−## Welding Consumables {toc}
+# Welding Consumables {toc}
```datasheet
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```
−### FCAW-G (gas-shielded flux cored arc welding) is the most widely used process for structural steel fabrication and field welding because it combines high deposition rates, all-position capability, and tolerance of the steel surfaces encountered in structural work. {note}
−### FCAW-S (self-shielded) is used in field conditions where wind disrupts external gas shielding, but self-shielded FCAW is generally prohibited for demand-critical welds in seismic applications per AWS D1.8. {note}
−### SMAW remains common for field welding, repairs, and in positions where continuous wire-feed processes are impractical. {note}
−### SAW is used in the shop for long flat-position welds such as beam flange-to-column flange connections and built-up member assembly. {note}
−### GMAW requires a stable, shielded shop environment and is less common for structural steel than for light fabrication. {note}
+## FCAW-G (gas-shielded flux cored arc welding) is the most widely used process for structural steel fabrication and field welding because it combines high deposition rates, all-position capability, and tolerance of the steel surfaces encountered in structural work. {note}
+## FCAW-S (self-shielded) is used in field conditions where wind disrupts external gas shielding, but self-shielded FCAW is generally prohibited for demand-critical welds in seismic applications per AWS D1.8. {note}
+## SMAW remains common for field welding, repairs, and in positions where continuous wire-feed processes are impractical. {note}
+## SAW is used in the shop for long flat-position welds such as beam flange-to-column flange connections and built-up member assembly. {note}
+## GMAW requires a stable, shielded shop environment and is less common for structural steel than for light fabrication. {note}
−### Welding electrodes, wires, and fluxes shall comply with AWS D1.1:2025 and shall be selected to match the base metal group and the minimum preheat and interpass temperature requirements of the WPS.
+## Welding electrodes, wires, and fluxes shall comply with AWS D1.1:2025 and shall be selected to match the base metal group and the minimum preheat and interpass temperature requirements of the WPS.
−### Filler metals shall meet the matching strength requirements of AWS D1.1:2025 for the applicable base metal; overmatching strength filler metals may be used only where the WPS and the SER permit them.
+## Filler metals shall meet the matching strength requirements of AWS D1.1:2025 for the applicable base metal; overmatching strength filler metals may be used only where the WPS and the SER permit them.
−### Low-hydrogen electrodes (H8 or lower designation) shall be used for all structural welding.
+## Low-hydrogen electrodes (H8 or lower designation) shall be used for all structural welding.
−### Filler metal packaging shall be in accordance with AWS A5-series storage requirements; opened packages of low-hydrogen SMAW electrodes shall be kept in portable electrode ovens or redried before use if exposed to ambient humidity for more than the manufacturer's stated window.
+## Filler metal packaging shall be in accordance with AWS A5-series storage requirements; opened packages of low-hydrogen SMAW electrodes shall be kept in portable electrode ovens or redried before use if exposed to ambient humidity for more than the manufacturer's stated window.
−## Shear Stud Connectors {toc}
+# Shear Stud Connectors {toc}
```datasheet
…7 unchanged lines
```
−### Shear stud quantity, layout, minimum and maximum spacing, edge distances, and deck orientation requirements are [[drawing: as indicated on the composite beam schedules and framing plans]]. {note}
+## Shear stud quantity, layout, minimum and maximum spacing, edge distances, and deck orientation requirements are [[drawing: as indicated on the composite beam schedules and framing plans]]. {note}
−### Shear stud connectors shall conform to ASTM A108 and shall be welded per AWS D1.1:2025 Clause 9 using a stud welding process qualified for the steel deck profile and base metal conditions present.
+## Shear stud connectors shall conform to ASTM A108 and shall be welded per AWS D1.1:2025 Clause 9 using a stud welding process qualified for the steel deck profile and base metal conditions present.
−### Studs shall be tested after welding by the bend test per AWS D1.1:2025 Clause 9.8.1; studs that do not meet visual inspection criteria shall be bent to 90 degrees for further evaluation.
+## Studs shall be tested after welding by the bend test per AWS D1.1:2025 Clause 9.8.1; studs that do not meet visual inspection criteria shall be bent to 90 degrees for further evaluation.
−### Where stud heads are found to be off-center or weld flash is irregular, additional studs shall be added adjacent to the defective stud rather than attempting to remove and re-weld the original.
+## Where stud heads are found to be off-center or weld flash is irregular, additional studs shall be added adjacent to the defective stud rather than attempting to remove and re-weld the original.
# Connections {toc}
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```
−### Preheat is required to prevent hydrogen cracking (underbead cracking) in higher-carbon-equivalent base metals and under conditions of high restraint, thick material, or low ambient temperature. {note}
+### Preheat is required to prevent hydrogen cracking (underbead cracking) in higher-carbon-equivalent base metals and under conditions of high restraint, thick material, or low ambient temperature.
### Minimum preheat temperatures per AWS D1.1:2025 are based on the carbon equivalent of the base metal, the material thickness, and the welding process. {note}
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### Beveled washers (wedge washers) shall be used where bearing surfaces are sloped more than 1:20 from perpendicular to the bolt axis.
−## Bolt Inspection {toc}
+## Bolt Installation Inspection by Tightening Method {toc}
### Snug-tight connections shall be verified by the QA inspector through visual inspection and random spot-checking with a spud wrench, verifying that all bolts are present, that plies are in firm contact, and that bolt heads or nuts have not backed off.
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min: 1
max: 6
− setpoints: [2, 3, 4]
+ setpoints: [1, 2, 3, 4, 6]
default: 2
```
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### Level II personnel shall perform tests and evaluate indications independently; Level I personnel may perform tests under Level II supervision but shall not independently evaluate results.
−## Bolt Inspection {toc}
+## QA Bolt Inspection Extent and Documentation {toc}
### The QA inspector shall verify bolt installation for each connection in accordance with RCSC 2020 Section 9 and AISC 360-22 Chapter N inspection tables N5.6-1, N5.6-2, and N5.6-3.
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## Storing steel directly on soil causes corrosion damage to the coating and introduces contamination at contact surfaces. {note}
+## Structural steel shall be delivered to the project site in the fabricator's standard bundling, with each piece clearly marked with its erection mark.
+
+## Members shall be loaded and transported to prevent distortion, impact damage to members or coatings, and contact with incompatible materials.
+
+## Long members shall be adequately supported during transport to prevent permanent sag.
+
+## At the site, steel shall be stored on timber dunnage or other supports that keep members off the ground surface.
+
```datasheet
label: Site Storage Requirements
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```
−## Structural steel shall be delivered to the project site in the fabricator's standard bundling, with each piece clearly marked with its erection mark.
−
−## Members shall be loaded and transported to prevent distortion, impact damage to members or coatings, and contact with incompatible materials.
−
−## Long members shall be adequately supported during transport to prevent permanent sag.
−
−## At the site, steel shall be stored on timber dunnage or other supports that keep members off the ground surface.
−
## Members shall be arranged to allow drainage; water shall not be permitted to pond on horizontal surfaces or inside HSS members.
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## Where a full exterior paint system is applied in the field, the painting subcontractor's warranty covers the complete coating system applied in the field.