Expansion bolts

Has anyone researched to find which expansion bolt has the highest tensile and shear strength in oh lets say 3/8" x 3"? I'm using Powers now, wondering if I could be using better.

What alternatives (appropriate for the application) are out there?

What is the application? I am assuming you are rap bolting? Would like to see someone place a powers on lead. I have also had good results from hilti kb3. (Kwik bolt). But if you want to spend the money, the fixe triplex are bomber, but you need a 12mm bit for em. Also check out the petzl longlifes.

Don't have data for any of these. But plenty strong...

I think Powers is pretty much the industry leader. Hilti may have slightly higher strength. You can download the data sheets from their websites. That data is a lot more accurate than a bunch of yahoos on the web.

"Would like to see someone place a powers on lead". I have placed Powers Power Bolts on lead. They are the strongest but they are expensive in stainless and are hard to install right (at all in fact). They are also so hard to replace that most will not be replaced in the original hole, at least the 3/8" ones I replaced.

I have switched to Powers Power Studs in stainless. They are easy to install and are very strong in the hard granite I am using them in.

Glue-ins are becoming all the rage on the net. Apparently you can heat them up with a blow torch and pull them out when the time comes. Data sheet is available on those too at Powers web site. These are what failed in "The Big Dig" in Boston. They used the quick set glue, not the recommended glue.

If you want them to be really strong, go to 1/2". The ASCA prefers that rebolters use 1/2" if they can power drill. Obviously it's a bit overkill on rarely repeated granite slab, but definitely best for anchors and for steep or heavily traveled routes.

If you are power drilling, 3/8" Power-bolts are easily replaced by upgrading to 1/2". Simply unscrew the old bolt, pull whatever you can get out with pliers, and blast through with a 1/2" SDS bit and a 36V power drill. Hard on bits but not that bad. With some patience it is possible to remove the old bolt without power tools - it depends how much you really want to remove it. But you definitely can NOT remove stud/wedge bolts.

Stud/wedge bolts are slightly weaker and can't be replaced in the same hole. If you must use them, please use 316 stainless steel (best) or 304 stainless steel (not as good), and never the carbon steel ones.

Power-bolts are one of the easiest bolts to install and are more resistant to poor installation (poorly sized hole, etc). Not sure what happened with you mschlocker, but those are very easy to use.

Tons of people use those on lead, it's no big deal. You can't place them one handed though (unless tricks are used that may decrease bolt strength)...

The most common error that can screw up any of these sorts of bolts is over-tightening the bolt - you can snap the bolt off entirely. Over torquing the bolt is probably the single biggest error made by experienced bolters...

WiledHorse wrote: Would like to see someone place a powers on lead.

Here you go:

Great shot, Mike!

I've place powerbolts on lead too, on slightly overhanging rock. Stainless is sorta soft enough you can jab the bolt in the hole, then, you get one well placed tap to start it...

Sounds like you better make sure you have a few extra bolts in the bag Brian!

But that's a whole lot better than the old-school tactics I've heard for one handed placement of 5-pieces (Power-bolts) - such as wallowing out the start of the hole, or pounding down the cone a bit before hand so that it will fit in the hole, yet not so much that it won't grab when you start tightening it - yikes!

Lots of good info, thanks everyone.

Greg Barnes wrote:Sounds like you better make sure you have a few extra bolts in the bag Brian! But that's a whole lot better than the old-school tactics I've heard for one handed placement of 5-pieces (Power-bolts) - such as wallowing out the start of the hole, or pounding down the cone a bit before hand so that it will fit in the hole, yet not so much that it won't grab when you start tightening it - yikes!

Yikes indeed. Used to do the smush the cone thing on the non-stainless powerbolts. They can take a bit of that abuse. The stainless are much more finicky. After jackin' out a few spinners, I learned to not smush the cone.

Yeah, always carry a few extra. How's that go? When you have everything to lose, you learn to play the game? Ha ha.

Could have down climbed I suppose...

Cheers, Greg!

Greg Barnes wrote:Tons of people use those on lead, it's no big deal. You can't place them one handed though (unless tricks are used that may decrease bolt strength)...

that's what i meant when i said would like to see someone place a powers 5pc on lead. should have clarified one-handed.

I did it in a big horizontal roof hanging by one arm once with a power drill. It took a lot of climbing back and forth to the last bolt to hang and rest. To get the bolt in I had to hold the head of the hammer against the bolt and jab it a few times until it stuck and then carefully tapped it in. People have been whipping on it constantly for almost 20 years. It is one I would like to replace with a glue-in though. Nowadays I would have just aided out on a couple little work bolts then removed them and patched

Nathan Scherneck wrote:Has anyone researched to find which expansion bolt has the highest tensile and shear strength in oh lets say 3/8" x 3"? I'm using Powers now, wondering if I could be using better. What alternatives (appropriate for the application) are out there?

Yep, powerbolts are the strongest, followed by Hilti KB-3s.

kennoyce wrote: Yep, powerbolts are the strongest, followed by Hilti KB-3s.

And you can make the Power-Bolt even stronger if you replace the grade-5 machine bolt with a grade-8 bolt. Of course that is overkill for rock climbing and a waste of time, but it will up the strength to that of most 1/2" bolts.

mschlocker wrote:Glue-ins are becoming all the rage on the net. Apparently you can heat them up with a blow torch and pull them out when the time comes.

3 questions.
Has hauling a blow torch to the crags become a rage on the net?
At what point in the route's history does it become time to remove these bolts?
If I lock off a bi-doight in the empty hole above, while scumming off the previously melted/now hardened epoxy below, would this be considered aid?

You can "prep" a 5-piece for lead bolting. Drill a hole in hard rock at home, hammer in the cone about 1/8-1/4", then yank it out. Voila, a slightly deformed end that can be shoved into a hole with one hand.

Tom-o Erectus wrote: 3 questions. Has hauling a blow torch to the crags become a rage on the net? At what point in the route's history does it become time to remove these bolts? If I lock off a bi-doight in the empty hole above, while scumming off the previously melted/now hardened epoxy below, would this be considered aid?

To answer:
1) A Mapp gas torch is like 2 lbs and the size of a water bottle.
2) I've seen plated last over 25 years now without even turning red, high grade stainless that is not subject to sea air should last a lifetime.
3)No, b/c that scenario ain't happening.

Nathan Scherneck wrote:Has anyone researched to find which expansion bolt has the highest tensile and shear strength in oh lets say 3/8" x 3"? I'm using Powers now, wondering if I could be using better. What alternatives (appropriate for the application) are out there?

I recommend stainless, even in dry climates. Greg is right on torque, buy or borrow a torque wrench to get a good feel. The torque on 3/8in power stainless is very low (max torque is 12 ft/lbs)!

On Powers, the tightening is just to set the cone/sleeve and prevent spinners. As long as it is set,any outward forces create additional expansion.

Tightening is even less important on wedge anchors. If the hole is good, once the bolt is in...it is NOT coming out...even before you tighten. Tightening will prevent spinners and properly set the wedge.

There is no reason to overtighten bolts.

The DATA you want:

Hilti Kwik Bolt 3 (See: Ultimate Loads in Normal-Weight Concrete) Table:
us.hilti.com/fstore/holus/t…(328-352)r020.pdf

Powers (See: Ultimate Load Capacity table on page 4):
powers.com/pdfs/mechanical/…

M Sprague wrote:I did it in a big horizontal roof hanging by one arm once with a power drill. It took a lot of climbing back and forth to the last bolt to hang and rest. To get the bolt in I had to hold the head of the hammer against the bolt and jab it a few times until it stuck and then carefully tapped it in. People have been whipping on it constantly for almost 20 years. It is one I would like to replace with a glue-in though. Nowadays I would have just aided out on a couple little work bolts then removed them and patched

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That's an old carpenter trick for one handed placement. Can be edgy on a delicate stance