8mm bolts?

Anyone use or can source expando 8mm bolts/hangers (for high quality granite/quartzite)? Placing 3/8 on lead is exhausting and I don't see the point, plus nobody makes 3/8 RBs anymore.

Are you looking for the 8mm drop in style anchors that Petzl use to make?  It appears Kong still makes them.

Kong 8mm bolt

Not sure of your specifics but you can also just use a 1/4” split drive bolt.  They come in 1 1/4” lengths. I’ve placed hundreds of them on lead.  Easy to pull and replace after getting the rope up.

Steel drive bolts (scroll down a bit)

Are you talking temporary bolt that you are upgrading yourself?

Cause 8mm/5/16 is really marginal except for real low fall factor situation like slab.

A 5/16 5 piece is a decent temporary bolt that would easy to upsize. About 3000 lb in shear. Way stronger than 1/4 Rawl drive.(compression bolt). 

Self drives are hard to remove and you end up with a 12mm hole. Thats fine if you are gonna deal with them yourself.  

Raumer sells 8mm wedge studs in SS but i dont know if there is a good domestic source. 

I'm with Mikey, just use 1/4" buttonheads. Bring a mix of those and 3/8" and use the 3/8" if you have a good stance, the 1/4" if it's dicey, then upgrade them right away.

The 5/16" 5-piece haven't been made for a long time.

Hadn't thought of them being discontinued but should have Greg.

FWIW Rawl drives dont work well in quartzite. Hole is usually undersize and rock often fractures placing the bolt.  

timothy fisher wrote:

Hadn't thought of them being discontinued but should have Greg.

FWIW Rawl drives dont work well in quartzite. Hole is usually undersize and rock often fractures placing the bolt.  

Yes, they also are not a good choice for limestone, basalt, most sandstone, or any "brittle" rock - they tend to spall/fracture the rock surface, sometimes quite severely. Same thing with patina on granite in some spots, which is why you want "long" 1/4" in some granite (1.5" instead of 1.25").

Back to the original question - I don't know if there's a (relatively) strong 5/16" expansion bolt option available these days, particularly one that is removable.

You can get the Raumer 8mm stainless wedge from Oliunid.com

Raumer 8mm wedge

Problem I see with these is they'd be hard to replace in an area where power tools aren't allowed, which I assume is the case for the OP.   

And regarding the spall/fracture of drive bolts, when I'm starting the hole I create a wide opening by holding the bit at 45 to the wall.  I just do that in a circle to create an oversized hole for the first 1/8 to 1/4".  I've found this reduces the fracturing.  I've only done this on granite so have no idea if it works on other rock types.

Have you looked at 5/16” Redhead sleeve bolts (lok-bolt style)? If they’re strong enough, they’d be pretty easy to remove using Vice grips, especially if you add extra washers between the hanger and nut so more of the sleeve is exposed

https://www.lowes.com/pd/Red-Head-1-1-2-in-x-5-16-in-Sleeve-Anchors/3043971?cm_mmc=shp-_-c-_-prd-_-hdw-_-ggl-_-LIA_HDW_126_Fastening-_-3043971-_-local-_-0-_-0&ds_rl=1286981&gbraid=0AAAAAD2B2W9zuNxLJE7YL5lp_6ystU6oV&gclid=EAIaIQobChMIudahkqK-9QIVDRpMCh3M3QuTEAQYAiABEgI5uPD_BwE&gclsrc=aw.ds

Mikey Schaefer wrote:

You can get the Raumer 8mm stainless wedge from Oliunid.com

Raumer 8mm wedge

Problem I see with these is they'd be hard to replace in an area where power tools aren't allowed, which I assume is the case for the OP.   

And regarding the spall/fracture of drive bolts, when I'm starting the hole I create a wide opening by holding the bit at 45 to the wall.  I just do that in a circle to create an oversized hole for the first 1/8 to 1/4".  I've found this reduces the fracturing.  I've only done this on granite so have no idea if it works on other rock types.

I have no idea what the description of that bolt says, but it's sold in USD?

Also, your assumption is usually wrong, but bolting 3/8 on lead is exhausting in any case. If you're lucky you'll get 3 bolts per fully charged Bosch 36v battery in quartzite.

I guess one question I have is, would anyone complain if the permabolts in good granite (or better) were 8mm 304 stainless expando. I know they have a bad rap due to people in euroland and straya placing them in soft rock, but I'm having difficulty finding issues with hard rock like good granite, basalt, and quartzite.

Trad Man wrote:

I have no idea what the description of that bolt says, but it's sold in USD?

The tech specs are in English.  Not sure what else you need to know.  And you can choose whatever currency you'd liked to be displayed on that website.  It is an Italian website that ships worldwide.

Also, your assumption is usually wrong, but bolting 3/8 on lead is exhausting in any case. 

Cool.  Next time you want people to help you google shit and provide some suggestions maybe be a bit more specific.  I guess I've just never been in a situation when using a power drill is as remotely exhausting as hand drilling.  

You need 4 amp hour battery for the 36v bosch. You can drill a bunch in very hard quartzite with that combo. 

It sure sounded to me that you were hand drilling.

Really no excuse for drilling smaller than 3/8 with a power drill IMO.

Mikey Schaefer wrote:

The tech specs are in English.  Not sure what else you need to know.  And you can choose whatever currency you'd liked to be displayed on that website.  It is an Italian website that ships worldwide.

Cool.  Next time you want people to help you google shit and provide some suggestions maybe be a bit more specific.  I guess I've just never been in a situation when using a power drill is as remotely exhausting as hand drilling.  

I don't see why you're jumping down my throat. I didn't even bring up drilling methods because it didn't seem relevant. You're the one making assumptions.

I'm perfectly capable of searching for shit (like the galvanic potential of 316 vs 304) but a lot of this stuff is esoteric and search engines (especially Google) are only interested in normie consumerism plus they like to take out search terms if they don't think they're going to make a buck on commissions. Google had largely become a waste of time and yes I did try their shit engine before posting here (maybe I should have tried it in eyetalian)

Why not drill 3/8 ss from stances and have a well equipped route for others to safely climb later, eh?

Trad Man wrote:

I guess one question I have is, would anyone complain if the permabolts in good granite (or better) were 8mm 304 stainless expando. 

I think the short answer is "Yes", because there aren't any which are strong enough (as far as I am aware). Except a 6mm glue-in in an 8mm hole, I think Jim Titt did testing on those and found them to be plenty strong - but I also remember him saying he wasn't making any 6mm solid-leg glue-ins.

One thing to note is that a wedge bolt is not really the stated diameter - the threads cut way into the actual diameter, which is why a 3/8" 5-piece with a 5/16" bolt core is still stronger than any 3/8" wedge bolt. A good example of this is how a 1/2" wedge bolt will easily fit into a 12mm bolt hole hanger, while a 1/2" sleeve can't - and that's the diameter of the "top" of the threads, let alone if you were to measure between the "troughs" of the threads. Considering that a 8mm or 5/16" wedge bolt, no matter how nice, is basically a 1/4" bolt, I would instead look into optimizing battery life and testing out some different drill bits to see if you can get a few more holes in the quartzite.

Trad Man wrote:

I guess one question I have is, would anyone complain if the permabolts in good granite (or better) were 8mm 304 stainless expando. I know they have a bad rap due to people in euroland and straya placing them in soft rock, but I'm having difficulty finding issues with hard rock like good granite, basalt, and quartzite.

I took a 60 foot fall when an 8mm wedge bolt pulled out of good granite.  Pretty sure it was only 16 years old.  I'd complain.

Haven't read all posts but 8mm A4 stainless are readily available from most European manufacturers (Fischer, Würth, MKT, Hilti, ...). I'm sure they have suppliers in the US or you can find a European site that ships internationally. Raumer sells 8mm hangers and might also sell bolts. Oliunid (linked above) is a legit website from Italy.

Pino Pepino wrote:

Haven't read all posts but 8mm A4 stainless are readily available from most European manufacturers (Fischer, Würth, MKT, Hilti, ...). I'm sure they have suppliers in the US or you can find a European site that ships internationally. Raumer sells 8mm hangers and might also sell bolts. Oliunid (linked above) is a legit website from Italy.

They (Raumer) do stipulate that they (8mm) are for caving and not climbing.

timothy fisher wrote:

They (Raumer) do stipulate that they (8mm) are for caving and not climbing.

That's not what OP was asking for. I haven't used them either and probably wouldn't. I think some alpine routes in the Alps may be equipped with these.

I wouldn't have been worried if I encountered them and my intuition would be that they are probably fine given the technical specifications. I haven't seen a test though and could be wrong. But aren't the screws in the 3/8" sleeve bolts common in the US essentially the same diameter (5/16") as 8mm wedge bolts?

Pino Pepino wrote:

I wouldn't have been worried if I encountered them and my intuition would be that they are probably fine given the technical specifications. I haven't seen a test though and could be wrong. But aren't the screws in the 3/8" sleeve bolts common in the US essentially the same diameter (5/16") as 8mm wedge bolts?

You should read Greg Barnes’ above post about bolt diameters…

C Williams wrote:

You should read Greg Barnes’ above post about bolt diameters…

Huh, I missed that post. Good to know.