Bolts are used on all metal buildings. So whether you are a general contractor or a DIY-er, bolts are important to your metal building makeup. Bolts make connections in both primary and secondary framing members. These bolts might differ in the type used. It’s important to understand the difference in bolt tightness as the installer is responsible in assuring the proper tightness of all bolts.

 

Turn of Nut Bolt Pretensioning

Unless indicated on construction drawings, turn of nut tightening does not require hardened washers to be used. All bolts are to be installed with washers positioned a specific way. The nut or head rotation should be applied to all fastener assemblies in the joint, progressing from the most rigid part of the joint in which pre-tensioned bolts have minimized relaxation.

 

Snug Tight Bolt Tightening

In simple terms, snug tight means that a contractor ensures that bolts cannot be removed by hand. All bolt holes should be aligned to allow the bolts to be inserted without damage to the threads. Bolts should be placed in all holes with washers and nuts threaded to complete the assembly. Compacting the joint to the snug-tight condition should progress systematically from the most rigid part of the joint. The snug-tightened condition is the tightness that is attained with a few impacts of an impact wrench or the full effort of an ironworker using an ordinary spud wrench to bring the connected plies into firm contact.

If you have difficulties imagining the above scenario, let’s give a visual description. Essentially, a snug-tight bolt is installed in the same way as the lug nut on the wheel of a car. For example, each lug nut is turned until it won’t turn anymore, and the pattern is cycled and repeated. The same is true with bolts. When snug tight bolts are used, loosening will not occur.

It’s important that bolts are properly installed to ensure the safety of the building frame. Contact our project consultants today to discuss your next metal building project. If your building has already delivered and you have questions, please contact your project consultant or our Field Service Team. For more information regarding steel buildings, visit Heritagebuildings.com.