Bolt Threads and Nuts

I've been seeing a lot of hangerless bolts and bad bolts lately, which got me wondering about the threads on the bolt (for removal purposes or putting hangers back on). Seems like the common sizes for expansion bolts are: 1/4", 3/8", 1/2", 8mm, 10mm, 12mm. However, they can have different threads on the bolt. I read that there are three main types: Coarse, Fine, and Extra Fine. Which ones are used in climbing bolts, particularly wedge bolts? I couldn't find the thread info on any site that I know of.

Also, it doesn't seem like bolt companies sell rated nuts by themselves. Is it normal to use generic hardware store stainless nuts, or do they need to be some sort of rolled nut that's tested and rated?

99% of the wedge bolts you'll see in the US are 3/8 coarse

Michael M wrote:

Is it normal to use generic hardware store stainless nuts, or do they need to be some sort of rolled nut that's tested and rated?

All bolts (climbing specific and hardware store) are sold with a nut included

99% of the wedge bolts you'll see in the US are 3/8 coarse

Thanks! Are most metric ones coarse then as well?

All bolts (climbing specific and hardware store) are sold with a nut included

Yeah, I just didn't want to buy a bunch of bolts just for the nuts (If I used the nuts to put hangers on existing bolts, I'd be left with a bolt that doesn't have a nut). I looked at different sites like Fixe and Team-Tough but they don't seem to sell nuts separately from bolts.

I know buying generic hardware store equipment like chains is considered bad practice, which is why I was wondering about nuts.

A 10mm nut will fit 3/8 stud but it will be loose and strip easy. You can buy better quality nuts at industrial supply places like McMaster-Carr.

Stailness nuts are easy to get. Dont bother if the stud is rusty. Put it on the list to replace.

1/2" bolts will usually be sleeve bolts, not wedge bolts. Those have a hex head on the outside, not threads and a nut. The vast majority are going to be 3/8s coarse as others have stated. If you want to throw hangers and nuts on them then go for it. If you want to pull bolts you can learn that online and here on MP (I did) but you'll save a lot of time if you just meet up with a developer and learn their process. Also, most developers replace wedge bolts with glue ins, which is another process to learn. Personally I think replacing with a 1/2" SS sleeve bolt is a cooler thing to do than a glue in (on a time frame of decades to centuries it makes route maintenance easier), but replacing hardware at all is a difficult and thankless job and you certainly won't find me saying bad things about the majority of rebolters that use glue ins. 

I have been fortunate to receive a lot of mentorship from knowledgeable people when it comes to route development and maintenance, and I think that is extremely helpful and perhaps even necessary if you're doing much to the rock. My two cents. 

Where have you been finding these bad bolts? If you get a chance, take a good focus close-up photo of each bolt. Local rebolters can use those to figure out how bad the bolts likely are, and also what tools will likely be needed for replacement. If you don't have contact info for your local climbing organization (or if you're somewhere that doesn't really have one), contact the ASCA by emailing me at greg@safeclimbing.org and I'll do my best to get the photos to local rebolters. If you don't have photos, email me about the bolts with as much detail as you can on exact bolts, routes, etc.

If you do add a hanger and nut to a bolt, just bring a few coarse threaded 3/8" nuts, and maybe a couple 10mm coarse (which will be labelled M10-1.50) and hangers, and make sure to NOT tighten them down that much - use locktite instead of cranking down. If there are hangers missing off of other sized bolts, you don't want to add hangers since the bolts will be super sketchy (or if they are 1/2", you won't likely have a hanger that will fit them).

And Ricky - while glue-ins are certainly gaining in popularity, most rebolters use stainless expansion bolts, the ASCA sends out probably 4 times as many of those as glue-ins (a few years back it was  10 times as many, at least if you're talking about non-seaside crags - for those it's 100% titanium glue-ins).

You can buy better quality nuts at industrial supply places like McMaster-Carr.

Oh these are really nice, thanks. Some of the prices are kinda steep though, you could get a bolt or two for the price of one nut lol.

 1/2" bolts will usually be sleeve bolts, not wedge bolts. Those have a hex head on the outside, not threads and a nut.

With sleeve bolts I was interested in the threads for removal purposes. I know some people use a threaded rod to fish the coned nut out of the hole after they get the bolt and sleeve out.

 If you want to pull bolts you can learn that online and here on MP (I did) but you'll save a lot of time if you just meet up with a developer and learn their process.

Yeah, I learned about bolts and removal from MP, ASCA, and HN2H. I don't plan on dedicating a lot to rebolting because of the time and cost (college student), but I know of a couple routes that could use some new bolts. Definitely going to meet up with someone though. Thanks for your insight!

Edit since I'm out of replies:

Where have you been finding these bad bolts?

A lot of climbs in the South Bay have wedge bolts with no hangers, which is why I was interested in putting hangers on. There are some old bolts there and up north of Hwy 50, but that area is pretty remote and doesn't get many visitors, so replacement isn't urgent. I do want to learn more about bolting/rebolting, so I was contemplating potentially going with someone with experience as opposed to just sending the info off.

Thanks for all of the info on hanger replacement

Greg Barnes wrote:

Where have you been finding these bad bolts? If you get a chance, take a good focus close-up photo of each bolt. Local rebolters can use those to figure out how bad the bolts likely are, and also what tools will likely be needed for replacement. If you don't have contact info for your local climbing organization (or if you're somewhere that doesn't really have one), contact the ASCA by emailing me at greg@safeclimbing.org and I'll do my best to get the photos to local rebolters. If you don't have photos, email me about the bolts with as much detail as you can on exact bolts, routes, etc.

If you do add a hanger and nut to a bolt, just bring a few coarse threaded 3/8" nuts, and maybe a couple 10mm coarse (which will be labelled M10-1.50) and hangers, and make sure to NOT tighten them down that much - use locktite instead of cranking down. If there are hangers missing off of other sized bolts, you don't want to add hangers since the bolts will be super sketchy (or if they are 1/2", you won't likely have a hanger that will fit them).

And Ricky - while glue-ins are certainly gaining in popularity, most rebolters use stainless expansion bolts, the ASCA sends out probably 4 times as many of those as glue-ins (a few years back it was  10 times as many, at least if you're talking about non-seaside crags - for those it's 100% titanium glue-ins).

Hmm, I was referencing reusing the same hole. When doing that don't you have to either go up a size or go glue in? Seems to me many rebolters don't bother with pulling wedge bolts. Are people pulling the bolt and then going longer or bigger wedges?

1/4" =6mm not 8mm. 

Like Greg was getting at, if these hangers were stripped, there's probably a reason. I would be very cautious about using bolts that have been taken apart if you aren't experienced enough to know if they are appropriate hardware for climbing, or the rock in the area.

For example, there's a couple of routes in the Red that have wedge bolts that have been stripped of their hangers, and it's because those are dangerous bolts to use in sandstone. 

Be very cautious, and at a minimum put a red tag on the first bolt if you do go through with it so youre the only person that is taking the risk to climb on unknown hardware.

Ricky Harline wrote:

Hmm, I was referencing reusing the same hole. When doing that don't you have to either go up a size or go glue in? Seems to me many rebolters don't bother with pulling wedge bolts. Are people pulling the bolt and then going longer or bigger wedges?

Yes, you go up in size, so the "average" bolt replacement in many rock types is to replace a 3/8" wedge bolt (or 3/8" sleeve bolt) with a 1/2" stainless 5-piece sleeve bolt. Glue-ins are the standard in limestone and in softer sandstone, and are becoming popular in many rock types. 

Michael M wrote:

A lot of climbs in the South Bay have wedge bolts with no hangers, which is why I was interested in putting hangers on. There are some old bolts there and up north of Hwy 50, but that area is pretty remote and doesn't get many visitors, so replacement isn't urgent. I do want to learn more about bolting/rebolting, so I was contemplating potentially going with someone with experience as opposed to just sending the info off.

I assume you're talking about Castle Rock and nearby crags? There's a long history of bolt issues up there, for decades it was illegal to even replace a bolt. Plus loads of vandalism and hanger theft over the years up there. I'll put you in touch with the BACC who have been doing replacement up there recently (after long negotiations with land managers). Look for my email, I can get you in touch with rebolters, and I'll also ask you for more details on the Hwy 50 crags, there are various folks replacing up in Tahoe.

so, about those nuts and a good example of what not to do...

ran across this gem at clark canyon yesterday ;-)

Michael M wrote:

.....There are some old bolts there and up north of Hwy 50,....

Yes, more detail.
I live in Pollock Pines and will gladly check out the suspect gear and do maintenance as needed!
Bad bolts be gone!

Cheers.