Box Bolts

Box Bolt – is an expansion bolt for structural steel connections to hollow section steel or where there is a “blind connection,” where you only have access to one side of the connection. As the bolt head is tightened, the cone is pulled up the bolt thread, causing the legs of the sleeve to expand until the cone locks the sleeve against the inner wall of the hollow section.

Materials: Mild Steel to BS EN 10083 Grade 1.1151 & Stainless Steel to BS EN 10088 Grade 1.4401

Finish: Zinc plated to BS EN 12329: Class Fe//Zn8//A & Hot Dip Spun Galvanized to BS EN ISO 1461

Installation is simple just insert the fastener into a pre-drilled hole, then tighten with a torque wrench.Boxbolt-installation

Box Bolt - Sizes, Dimensions and Safe Working Loads

Product CodeDiameter (inch) & SizeSetscrew LengthClampingRange (X)
Min - Max
Across Flats of SholderShoulder ThicknessSleeve DiameterHole DiameterSafe Working Tensile(lbs)Safe Working Shear(lbs)Torque (ft lb)
BQ1Z06*1/4 Size 11-3/4"1/8"7/8"11/16"3/16"3/8"7/16"2872479314
BQ1_085/16 Size12"3/16"1"7/8"1/4"1/2"9/16"5071591718
BQ2_085/16 Size22-3/4"11/161-13/167/8"1/4"1/2"9/16"5071591718
BQ3_085/16 Size33-9/16"1-3/162-5/8"7/8"1/4"1/2"9/16"5071591718
BQ1_103/8 Size 12"3/16"7/8"15/16"1/4"11/16"3/4"97181098533
BQ2_103/8 Size 22-3/4"11/16"1-11/1615/16"1/4"11/16"3/4"97181098533
BQ3_103/8 Size 33-9/16"1-3/8"2-1/2"15/16"1/4"11/16"3/4"97181098533
BQ1_121/2 Size 12-3/16"3/16"1"1"5/16"3/4"13/16"130151267659
BQ2_121/2 Size 23-1/8"3/4"2"1"5/16"3/4"13/16"130151267659
BQ3_121/2 Size 34"1-9/16"2-3/4"1"5/16"3/4"13/16"130151267659
BQ1_165/8 Size 13"3/16"1-3/8"1-7/16"3/8"1"1-1/16"2619929578140
BQ2_165/8 Size 24"1-3/16"2-3/8"1-7/16"3/8"1"1-1/16"2619929578140
BQ3_165/8 Size 34-3/4"2-3/16"3-1/8"1-7/16"3/8"1"1-1/16"2619929578140
BQ1_203/4 Size 14"5/16"1-5/8"1-13/167/16"1-1/4"1-5/16"3693233804221
BQ2_203/4 Size 24-3/4"1-3/8"2-13/161-13/167/16"1-1/4"1-5/16"3693233804221
BQ3_203/4 Size 36"2-9/164"1-13/167/16"1-1/4"1-5/16"3693233804221
Minimum edge distance = Dim B + the thickness of hollow section


The loads stated above are based on the LRFD (Load & Resistance Factor Design) method recommended by the AISC for bolted steel connections. This uses a factor of 0.75 of the ultimate load and therefore equates to a 1.33 to 1 factor of safety that we have applied to our published loads above. The overall strength of the connection is governed by the strength of material our BoxBolt is connecting into; therefore, this should be checked for structural capacity by a structural engineer.
Approvals – The published loads are taken from physical testing in hollow structural section which are then verified by Lloyds Register Type Approval. The BoxBolt is also tested and approved by DIBt (Deutsches Institut fur Bautechnik) which complies with the DIN 18800 and Eurocode 3 design methods for bolted steel connections. A design guide and calculator is available when using these methods. Please ask our technical team for more information.

Box Bolt - Hole Dimensions and Positioning

Box Bolt SizeDim (A)Dim (B)Dim (C)
Minimum edge distance = Dim B + the thickness of the hollow section

The Box Bolt by LNA Solutions, A KEE Safety Company

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