5 piece bolt removal, draw stud options
|
Recently found a 3/8 5 piece that needs some attention, and am getting the tools together to pull it (building on my wedge bolt removal kit). Process seems straight forward. Remove the bolt and hanger, cut threads in the sleeve, thread a draw stud and pull the sleeve using the bolt extractor, then fish the rest of the bolt out of the hole. Only thing I'm having trouble wrapping my head around is whether there is any difference between a draw stud (as recommended) and a piece of 3/8 threaded rod? I can get the rod at the hardware store, draw stud will take more time to get in and I'd have to pay shipping. Any reason to use one or the other? |
|
IIRC, draw studs are usually made of higher tensile steel vs all thread so you'll be less likely to snap the pulling rod during extraction. Otherwise, 3/6-16 is 3/8-16 |
|
Well the size that works best for 3/8 5 piece is 9mm. If the sleeve wont come uneasily with a tap best bet may be to drill out the whole mess with 1/2 inch rebar ready SDS bit. You might have to make the 9mm threads if you want to go that route. |
|
Greg Kuchyt out of Vermont uses grade-5 3/8" threaded rod --> https://www.vtboltreplace.org/knowledge/bolt-removal/5-piece-sleeve-bolts/ |
|
Thanks all, that makes sense. Just wanted to make sure I wasn't missing something and end up not being able to pull the bolt or screwing it up and have to patch and move the placement. Sounds like higher grade threaded rod or a long grade 5 or higher bolt with the head cut off threads cleaned up would be the way to go. |
|
ACE Hardware has 3/8”-16 to 3/8”-16 studs, originally meant for an engine I think, in their hardware section. Black metal with a short unthreaded section in the middle. Maybe only available in 3” length, but it’s sufficient for short 5-piece. |
|
Drew Nevius wrote: The sleeve often fragments when using a 3/8” tap. Pull what you can, and then drill through what’s left of the sleeve if you have to. You can also carry one of those small pinhead-like magnets to fish out the sleeve fragments if it breaks apart. Could help minimize re-drilling issues if that occurs |
|
So 3/8 tap i have handy measures 0.3780 O.D. |
|
The actual size of the hole in the rock is larger than 0.375". I used a 9mm tap for a while, but I found the threads did not bite deeply enough in to the sleeve. |
|
Gregger Man wrote: The actual size of the hole in the rock is larger than 0.375". I used a 9mm tap for a while, but I found the threads did not bite deeply enough in to the sleeve. Thanks Greg! Found those online, but was hoping to get out in the next few days to address this and sometimes the availability of specialty tools is limited in town. Sounds like its worth calling the local auto parts store to see if they have something like this in stock. |
|
shucks, so M9x1 is not the solution? I thought I had it licked! |
|
These are even nicer than the automotive studs since they have a flat ground in the middle for a wrench. |
|
Also- a plug or taper tap cuts the threads gradually deeper. The bottoming tap has full depth threads at the leading edge. Rusty sleeves often break apart right at the lowest-cut thread, and the bottoming tap does not help matters. It might be better to use a plug or taper tap and to slightly chamfer one or two leading threads on the draw stud. That way you aren't expanding the shallow-cut threads at the deepest point, and you'll get a more solid connection with more surface area/thicker sleeve remaining. |
|
You don't pull a 5 piece the same as a wedge bolt. I've pulled and replaced a lot of 5 piece bolts and the best way is to use a framing hammer and take the hanger and washer off, reinstall hanger w/o washer so you can get the claw under the hanger and fing yard on it, tap the bolt head back in to disengage the cone from the sleeve and repeat, and repeat..... sometimes it takes 15 minutes and sometimes and hour. It comes out ever so slightly. Soapy water mixed with a little alcohol helps if you squirt some in the hole. Or you can just drill it out and fish the hole with a magnet. You'll go through bits but you only have one hole not route after route of bolts to replace. Wedge bolts are easy to remove compared to 5 piece. Good luck. |
|
lsdclimber Ellis wrote: Although your framing hammer approach apparently works, calling that the best way is pretty bold. By pulling on the bolt that way you are using the cone to push the sleeve out rather than using tapped threads and a draw stud to actually pull the sleeve using a purely axial force. Knock yerself out if you like the framing hammer - but a low friction linear puller has much more mechanical advantage and is quite a bit faster. When the bolts are just rusty enough to stop being slippery but not yet totally bonded to the rock, you can insert a 5/16-18 draw stud and pull directly on the cone to extract the whole mess. It doesn't work if the bolt is new because the cone will just re-engage. On really rusty bolts the sleeve just won't slide by being pushed. |
|
I've had limited success with the draw stud and pull hard technique-- in the sandstone around Santa Barbara at least, it tends to shatter the rock around the bolt as it comes to the last couple of inches of bolt in the rock. With a longer replacement bolt, you can drill past the blown out part and fill in with some instacrete, but boy it doesn't look that great. Gregger, I've just invested a bunch of time machining a 9mm-3/8-16 draw stud that interfaces nicely with a YABR that I have access to. I'm really hoping that it works better than tapping the sleeve with 3/8-16. In the rock around here the sleeves just tend to split open rather than tap easily with the 3/8 tap, so I'm hoping the 9mm tap will lower the cutting forces enough to not mangle the sleeves. |
|
Just remove the hangar and bolt then drill the rest out, and put in a glue in. Saves a ton of time and money over the whole system required to gently and painstakingly *maybe* get all the pieces out over possibly a long period of time. |
|
Jesse, sometimes this works and sometimes it doesn't. The rock here is soft enough under the hard patina that the cone and remainder of the sleeve sometimes just gets pushed out of the way into the side of the hole. this renders the hole completely unusable |
|
Lincoln, I don't think that is a problem if you are using glue ins. In fact, a hole that is a little wider in the back arguably is better in soft rock with glue. If there is metal left in there it really doesn't matter with glue. At least this is the advice I have followed and it seems to work well. Interested in any flaws to this line of thinking though. |
|
Jesse Morehouse wrote: This. Tapping the sleeve generally just cuts it into pieces because the tolerances are so tiny. The SDS bits for concrete w/ rebar make pretty short work on the sleeve and cone. A magnet wand is also key for fishing prices of metal out of the hole afterwards |
|
Blake M wrote: There is definitely a time vs money trade-off because removing all the hardware will take much longer but you are certainly going to go through more bits when drilling it out. That's really just a personal choice. (Edit: I've done both) As for the concerns about oversized holes or metal remaining in the bottom or side, just buy an epoxy rated for cracked concrete and you'll be fine. Don't take my word for it though. Thankfully folks are doing this kind of testing so we can be confident we aren't making major mistakes. See the video below. https://youtu.be/8pgFzVqVEJY |