Design Tools

Technical Services

The Excel tools available from BlindBolt have been prepared to ease some common connection design tasks.

The tools cover:

  • The calculation of bolt bearing resistance
  • The calculation of the resultant maximum load on a bolt subject to an in-plane moment and a shear (typically an end plate connection on a hollow section carrying a torque and a shear)
  • The calculation of wall resistance when fixings to a hollow section are subject to tension (typically an end plate connection to a hollow section)

NOTE: Each tool includes macros which must be enabled in Excel to correctly use the tools.  Security issues may prevent the downloading of files with macros, which is why the files are offered here in zip format.

Technical Design Tools from Blind Bolt

BlindBolt accept no liability for the use of these tools.
Users should confirm that the results are correct.

Errors, bugs and suggestions for improvement should be sent to

Blindbolt bearing resistance to
BS EN 1993-1-8

Calculate the bearing resistances of Blind Bolts, HD bolts and TW bolts in accordance with BS EN 1993-1-8 and the UK National Annex.

  • Minimum pitch, gauge, end and edge distances are verified.
  • Designer can select from steel grades S235, S275 and S355.
  • “inner” and “end” bolt bearing resistances calculated.

Blind Bolt
Bolt Group

Independent of design standards, this tool determines the resultant shear force (in kN) on the outermost bolt of a bolts group subject to a torsion and a shear.

  • A load eccentric to the bolt group
    (causing a moment)
  • End plate connection on a hollow
    section carrying torsion.

The tool does not verify the bearing resistance.

Wall Resistance

Calculate the wall resistance of a hollow section when a group of fixings are subject to tension.  Resistance calculated in accordance with CIDECT Design Guide 9, or AISC Design Guide 24 (2024)

  • Common grades of hollow section
    are included
  • Calculate the load on the fixings,
    allowing for an unequal distribution
    where necessary, following the guidance
    of AISC DG 24.

Contact the Blind Bolt Technical Team

If you have a question or query, or would like to arrange a webinar for your company, please complete the short form below and a technical representative will contact you to discuss your requirements.

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