Bolt length for pretension in AISC 348 1

[canwesteng]

AISC 348/RCSC spec gives the amount of rotation for turn of the nut based on the bolt length. Is this the length of the bolt itself or the length of connected parts between the bolt head and nut? It doesn't make sense to me that the length of bolt past the nut affects the amount of pretension afforded by turn of the nut, since it is unstressed.

 

[jhnblgr]

Flat faces under bolt head and nut.

https://cdn.docsie.io/document/workspace_xDo6jFMbRlfjgA3QD/doc_SOJ6SQXTep0RsYduq/file_XTQitHzjysNafitTr/tds_012_turn_of_nut_installation_6cb35249-37e6-76b7-213a-65d9523f0e6d.pdf

 

[HTURKAK]

...Is this the length of the bolt itself or the length of connected parts between the bolt head and nut?

Additional info. for the doc . provided by JHNBLGR , the use of washers are required depending on the installation method, bolt , and hole type. So the length of the bolt should cover length of connected parts and thk of washer.

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[DrZoidberWoop]

If you want to go on a deep dive, read through ASME B18.2.6. It contains the manufacturing spec's for high strength hex and TC bolts. The AISC manual length formulas are OK, but over the years I've found that their bolt length recommendations tend to be long and occasionally result in bolt jamming or thread run-out.