Galvanized TC (tension-control) bolts - corrosion at sheared ends 1

[Geoffre14]

Does anyone have experience using galvanized TC bolts outside? A basic property of TC bolts is the ends are sheared off during install. This leaves a surface without galvanizing, which starts corroding immediately. Is this something I should be concerned with? Why even make galvanized TC bolts at all if the product is inherently flawed?

Appreciate your input.

 

[Ron]

Coat each sheared end with cold galvanizing compound. Not a big deal.

 

[BridgeSmith]

Yeah, what Ron said...especially if it's a corrosive environment or aesthetics are important. However, under normal outdoor exposure conditions, it would take at least several decades for it to rust enough to matter structurally.

Rod Smith, P.E., The artist formerly known as HotRod10

 

[Agent666]

I went to a presentation last night on TCB's given by a guy from the UK who worked for a company called TCB. They don't galv their bolts but have a proprietary coating called Greencote which thermally/chemically changes the surface.

Someone asked this very question, and the answer was either cold galv it and then paint it if it's a visual concern, or just leave it. So similar to Ron's recommendation. In the presentation the durability testing they showed had all the splines still attached, so take from that what you want.

 

[NS4U]

Keep in mind that TC bolts are required to be mechanically galvanized, which is generally less durable than hot dipped galvanized a325 bolts. Depending on the use and exposure, I will typically specify HDG pretensioned A325 instead of galv TC bolts

 

[Geoffre14]

Thank you for the help everyone.