Free Steel Connection Check Calculator — AISC 360
Check all steel connection limit states in one place: bolt group shear and tension, weld group strength, block shear rupture, shear tab capacity, stiffener requirements, and prying action in end plates. Covers AISC 360-22 Chapter J, AS 4100 Section 9, EN 1993-1-8, and CSA S16 Section 13.
Connection types: single-plate shear tabs, double-angle connections, end-plate moment connections, gusset plates, bracket connections, and splice plates.
How to Use
- Select connection type from the library.
- Enter connection geometry: plate dimensions, bolt layout, weld size and length.
- Specify material properties: Fy and Fu for all plies, bolt grade, weld electrode.
- Apply factored loads: moment, shear, axial at the connection interface.
- Review results: individual utilization ratios for all limit states.
Design Checks Performed
| Limit State | AISC 360 | AS 4100 | EN 1993-1-8 | CSA S16 |
|---|---|---|---|---|
| Bolt shear + bearing | J3.6, J3.10 | Cl 9.3 | Cl 3.6.1 | Cl 13.12 |
| Weld strength | J2.2 | Cl 9.7 | Cl 4.5 | Cl 13.13 |
| Block shear | J4.3 | Cl 9.2.2 | Cl 3.10.2 | Cl 13.11 |
| Prying action | J3.6 | Cl 9.3.2.2 | Cl 6.2.4 | Cl 13.12 |
| Shear tab flexure | J4.5 | Cl 9.3.1 | Cl 6.2 | Cl 13.10 |
| Web local yielding | J10.2 | Cl 5.13 | Cl 6.2.6.2 | Cl 14.3 |
| Web crippling | J10.3 | Cl 5.13 | Cl 6.2.6.3 | Cl 14.3 |
Prying Action Overview
Prying action occurs in tension-loaded bolted connections (such as end plates) where bolt tension induces flexure in the connected plate, amplifying the actual tension demand on the bolts. AISC 360-22 Section J3.6 provides the prying action equations. The key parameters are the plate thickness (tp), bolt gauge (g), and the ratio of flange flexural stiffness to bolt axial stiffness. Increasing plate thickness is the most effective way to reduce prying amplification.
Frequently Asked Questions
What is the most common governing limit state for steel connections? For shear connections, bolt shear or bearing at the bolt holes typically governs. For moment connections, either weld strength at the beam flange or prying action in the end plate governs. Block shear frequently governs in gusset plates and coped beams. Always check all applicable limit states — the weakest link determines the connection capacity.
How does block shear differ from bolt bearing failure? Block shear is a rupture failure along a path combining shear planes (parallel to load) and tension planes (perpendicular to load), causing a block of material to tear out. Bolt bearing is a localized crushing failure around a single bolt hole. Block shear typically governs when bolt groups are close to a free edge; bearing governs for interior bolts with adequate edge distance.
What is the minimum edge distance for bolt holes in structural steel? AISC 360-22 Table J3.4 specifies minimum edge distances by bolt diameter and edge type (sheared or rolled/plasma-cut). For 3/4-inch bolts, minimum edge distance is 1-1/8 inches for sheared edges and 7/8 inches for rolled edges. These are absolute minimums — practical edge distances for full bearing capacity are 2-3 times the bolt diameter.
Is this connection check calculator free? Yes, completely free with unlimited calculations. No registration required.
Related pages
- Steel bolted connection design
- Weld group calculator
- Tension member design
- Bolt bearing reference
- Welded connection reference
Disclaimer (educational use only)
This page is provided for general technical information and educational use only. It does not constitute professional engineering advice. All structural designs must be verified by a licensed Professional Engineer (PE) or Structural Engineer (SE). The site operator disclaims liability for any loss or damage arising from the use of this page.