Re-chase anchor bolt threads
Re-chase anchor bolt threads
(OP)
I was asked to inspect existing anchor rods that are 1.5" diameter, cast in place, located outdoors. They anchored a piece of equipment that had been temporarily removed, but would be re-installed after my inspection.
Overall, they appeared to be in good condition. Almost all of them showed signs of very minor surface corrosion and thread wear but nothing unexpected.
I briefly spoke to the contractor who indicated that he planned to "re-chase the threads". After a quick google search, it seems that this is simply a method of cleaning the threads since no material is actually removed.
Is this correct? Any potential issues with re-chasing threads?
Overall, they appeared to be in good condition. Almost all of them showed signs of very minor surface corrosion and thread wear but nothing unexpected.
I briefly spoke to the contractor who indicated that he planned to "re-chase the threads". After a quick google search, it seems that this is simply a method of cleaning the threads since no material is actually removed.
Is this correct? Any potential issues with re-chasing threads?






RE: Re-chase anchor bolt threads
Mike McCann, PE, SE (WA)
RE: Re-chase anchor bolt threads
RE: Re-chase anchor bolt threads
It is not precise to say that it removes no material, unless the thread is already/still perfect.
"Re-chasing" suggests the threads have been chased already, which may or may not be true. It seems pretentious to me.
The rust will probably remove material from the die, which does the die no good. I'd suggest pre-soaking the rust with "PB Blaster" or something similar, to make the die's life a little easier.
Mike Halloran
Pembroke Pines, FL, USA
RE: Re-chase anchor bolt threads
http://www.grainger.com/product/OTC-Thread-Chaser-...
Maybe "thread restorer" is a gentler still product.
https://www.youtube.com/watch?v=7jgiSjq5Zxs
Some folks just wind a die over the thread, and if the start of the thread is distorted then things can get out of synch, so the threads are narrowed or worse.
RE: Re-chase anchor bolt threads
The NAPA tool comprises what are basically hardened nuts, that may or may not be notched to have a cutting edge. I have chased distorted studs by grinding a notch in one face of the mating nut, chasing the thread, and then using the same nut, reversed, to complete the joint; I'm rarely that lucky.
Mike Halloran
Pembroke Pines, FL, USA
RE: Re-chase anchor bolt threads
RE: Re-chase anchor bolt threads
Mike McCann, PE, SE (WA)