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Atlas TubeAtlas TubeWhere you can use this: Atlas Tube HSS Connections Hub onlyStatus: Beta · Region: US · Design codes: AISC 360-22, AISC Steel Construction Manual (16th ed.), AISC Design Guide 24

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What this calculator does

Sizes and checks a single-sided shear connection between an HSS beam and an HSS girder, to AISC 360-22, the AISC Steel Construction Manual (16th edition) and AISC Design Guide 24. Framing an HSS beam into an HSS girder rather than a column is standard in transfer and podium framing, and it introduces limit states a column connection never needs: the girder carries its own axial load, it can twist under the eccentric beam reaction, and its walls need a slenderness classification at the connection. Before this calculator those checks had to be hand-built by combining the beam-to-column procedure with Design Guide 24’s chord-stress and axial interaction tables.

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Video walkthrough

This video covers the coped shear connection into an HSS column. The girder presets below add the girder-side limit states on top of the same beam-side procedure.

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Choosing a preset

Five presets share the same template. Pick the one that matches your detail before entering geometry.
The through-bolt presets exist because there is no accessible back face inside a closed section. A proprietary blind fastener solves the access problem but restricts you to a narrow diameter range with longer lead times and higher unit cost. A through bolt is cheaper and more available, and capacity is governed by bolt shear rather than a slip-resistance limit state.

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Inputting key properties

  1. Select the preset and connection type. This sets which geometry inputs appear below.
  2. Set the plate configuration. Conventional or Extended, per AISC Steel Construction Manual Part 10. Extended unlocks multiple bolt rows, variable spacing, out-of-plane moment on the girder, and the combined axial, shear and flexure interaction indices.
  3. Choose the girder and beam HSS sections and grade. The girder can be rotated in both the top and side views to match field conditions.
  4. Enter cope dimensions (coped presets only): cope height and cope length.
  5. Enter plate geometry: thickness, width, vertical length, and beam setback.
  6. Enter weld size.
  7. Enter bolt properties: size, grade, thread condition, vertical and horizontal spacing, edge distances. On blind-fastener presets the diameter list is restricted to Shuriken-compatible sizes. On exterior-plate presets the sheet also checks plate-to-plate spacing and the clearance needed for the bolt heads on the exterior faces.

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Applying loads

Enter either individual load types, swept through the ASCE 7 combinations automatically, or pre-factored demands under LRFD or ASD. Available demands:
  • Factored shear in the beam
  • Factored axial tension and compression in the girder (extended plate configuration)
  • Torsion demand in the girder (extended plate configuration)
Governing load combinations are tracked separately for tension and for compression.

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Girder torsion restraint

The sheet carries a Girder Restrained Against Torsion? toggle. Torsion resistance is checked under AISC 360-22 Section H3.1, and once torsion demand exceeds roughly 20% of capacity the sheet raises an H3.1 / H3.2 interaction note.

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Reviewing the calculations

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Girder-side limit states

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Beam-side and connection limit states

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Reading the results

Results report as governing demand-to-capacity ratios grouped by element. The connection detail diagram reflects the cope, the plate position (interior or exterior), the through-bolt or blind-fastener group, and the rotated girder geometry.

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Assumptions and exclusions

  • Single-sided connections only.
  • Where the girder is not restrained against torsion, the torsion check governs more often than engineers expect. Check the toggle matches your framing.
  • Blind-fastener presets are limited to Shuriken-compatible bolt diameters by design, not by code.