Formally noting on a drawing to marr exposed bolt thread?

[cadialg]

Hi all,
I have recently designed some steel supports bolted to ex. concrete for electronic signage at a train station. Client is concerned about people stealing/tampering with the exposed nuts on the epoxied anchors - I am not too concerned but have suggested that we specify Loctite 263 (~permanent thread locker). They have come back and suggested marring the bolt threads above the nut as a 'permanent' solution. I have specified this approach in the field before but never as a notation on a formal drawing - looking for input on how to specify this (or if it is even necessary). Thanks!

 

[SnTMan]

cadialg, have seen / done similar. Drawing note, "peen" or "stake" exposed threads, words to the effect.

Put it on the drawing only if you want it done

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[racookpe1978]

"Peen exposed threads after torqueing to xxxxd.x foot-lbf. Then prime and preserve per Note yyyy of Spec zzzz."

 

[Tmoose]

What thread size on the anchors ?

Something like this would likely be more secure than a few chisel marks, and look more professional too.

https://www.fastenal.com/products/details/11137456

https://www.fastenal.com/products/details/11102355

 

[desertfox]

Hi

Try using vandal proof nuts or make some, these consist of a smooth spherical shape body with a threaded hole and at one end have a small hexagon section which allows tightening to a pre-determined level at which point the hexagon section breaks off the threaded sphere.

see this link:-

https://www.bolt.com.au/stainless-steel-vandal-proof-nuts-c-1010_3669_1753_1771.html

“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein

 

[Screwman1]

The railroad industry requires that bolt threads are "chisel checked or tack welded" after torquing. This is actually an AAR regulation to prevent loss of the the nut on threaded connections. Of course the chisel checking doesn't prevent initial loss of clamp load, but it makes the powers that be feel good.

 

[SnTMan]

Well, let's recognize that in some situations loss of the fastener is far worse than loss of the preload.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand