3/8" Hilti Threaded Rods

Hello,

I am looking to pick up some threaded rods for protection bolts. I can get the HILTI HAS-R in 316.

https://www.hilti.com/c/CLS_FASTENER_7135/CLS_CAPSULE_ADHESIVE_ANCHORS_7135/r4234

My question is will 3/8" be enough or will I need to go up to 1/2"?

The "steel design strength" for the Hilti in shear is ~12 KN, but it comes with this note:

Shear = ϕ 0.60 Ase,V futa as noted in ACI 318-14 Chapter 17. For 3/8-in diameter threaded rod, shear = ϕ 0.50 Ase,V futa

Does this mean that the strength is higher, but a reduction factor was worked in to meet certain standards?

I prefer to stick with 3/8" because I already have the hangers for that size.

Thank you

Please don’t use threaded rod for glueins, even if it’s the designed as such for construction purposes. Your hangers will always be loose, the  maximum torque for glued in threaded rod is too  low to keep them from constantly loosening. You are better off using glueins designed for climbing. Also, 3/8 threaded rod is generally too weak for climbing applications. 

Thank you for your comment.

I do not see hangers loosening as any worse on 1/2" hilti rods than their KB3 bolts. The torque is 30 ft-lb for 1/2" HAS-R rods vs 20 ft-lb for 3/8" KB3 bolts.

I have used loctite and nylon lock nuts successfully on KB3 bolts over the years.

Thank you

Fishy Boi wrote:

Thank you for your comment.

I do not see hangers loosening as any worse on 1/2" hilti rods than their KB3 bolts. The torque is 30 ft-lb for 1/2" HAS-R rods vs 20 ft-lb for 3/8" KB3 bolts.

I have used loctite and nylon lock nuts successfully on KB3 bolts over the years.

Thank you

Well damn, sounds like you’ve already made up your mind... so why are you asking for advice? Especially when you are going to discount the advice of someone with decades of route development and replacement experience?

For the record, nylon lock nuts are a terrible idea on wedge bolts. The bolt WILL loosen over time as the stainless steel relaxes (I’m assuming you are being responsible...) and the nylock will cause the bolt to spin when you attempt to snug it down. Now you have a true spinner, with the nut stuck on, and cleanly replacing a wedge bolt with a stuck nut is difficult and time consuming. Same with loctite btw. If you are concerned about a bolt loosening use a stainless split washer, those are specifically designed for stainless “creeping” and will allow for any needed loosening or tightening.

There's a reason most on here will not be supportive of threaded rod for glue in use.  To quote Jim on this beaten-to-death topic - 

Cheap threaded stainless rod is shockingly weak, the expensive still pretty grim in the smaller sizes and really hard to get. With a hanger, nut and washer more expensive than a glue in bolt anyway.
Glued-in threaded bar is usually annoying as hell as the hangers come loose, the resin creeps under long-term load.

Threaded rod is something of a half-way solution and has no real advantages and some big disadvantages.
First off it´s usually not cheaper as you have to buy the rod (and cut it) then buy a washer, nut and hanger + you need all the stuff to do glue-ins as well.
Second the quality of most threaded rod is appalling, from a 10mm rod you are lucky to see 8-9kN before it shears off. There is good threaded rod available but this isn´t cheap! Many of the anchor manufacturers also supply threaded rod fasteners, Hilti for example supply a large range in both Imperial and Metric threads.
Bonding to the threads isn´t an issue, that the resin manufacturers also supply threaded fasteners makes this obvious
As Francis mentioned creep can be an issue, the Australians has problems with this if I remember rightly. All resins creep to some extent when they are under continuous load and keeping a hanger tight takes a fair amount of force so the resin can start to release the bolt especially in high temperatures.
Since you have to go to all the effort of glueing the bolt in but you still end up with a hanger that can be stolen or come loose, will damage your karabiners and can´t be lowered from the whole idea seems a bit silly, probably why it isn´t popular!

Hello,

I have used nylon lock nuts and purple loctite for years and have not had any spinners with the Hilti KB3 bolt.

I check many of the bolts I have placed every few years for spinners and have had none so far. Nor have I had any issues with any seizing with nylon lock nuts or blue loctite coming off if needed.

I have read stories of some people having issues here, perhaps they use cheaper bolts with machined threads?

As to the original question, it was simply one of 3/8" versus 1/2" strength with the Hilti HAS-R.

For access reasons having the first few bolts with removable hangers is quite important.

Some climbers here do not respect "keep off" signs and crag closures. Potentially jeopardizing access.

Thank you.

To the original question yes that strength value is not the breaking load limit. 

Just because junk stainless wedge bolts are bad is not an argument against all wedges. The same is true for threaded rod. I buy stainless rod from reliable industrial sources like McMaster Carr. 

I have an engineering background and have been working in a technical field for over 30 years. I can think for myself and have no problem doing things that are not trendy or popular. 

I will use threaded rod in 7/16 in or 1/2 diameter or mechanical bolts for top anchors. Some time 3/8 in great rock.  I have only rarely used glue in bolts for top anchors. When i do I am carefull to limit the mechanical wear that could take place as maintaining the glue ins is an issue.

Hello timothy,

Thank you for your advice.

I believe I will just go with 1/2" threaded rod to be certain. For the first 2-3 bolts anyways for removability due to access issues.

The nice thing about using Hilti anchor rods is that there is little question about its quality.

May I ask what glue you are using with your threaded rods? And what drill bit diameter you are using with the 1/2" rods?

Thank you

If resin has an issue with creep, then could you mix small individual batches of cement?

I've installed about 20 bolts (two routes) with quick-setting cement, it's quite entertaining! Taught by a master of the trade, he'd bolted maybe 1000 bolts and climbed 8b.

You need a dessert spoon bent to more of a scoop shape, a mixer wire and a prodder to get the stuff down the hole, a dentists mirror ground smaller to go in the hole is what we had. Then a black-powder pouch to dose the cement (or guess) and a water bottle and a plastic tube. Dose the cement, suck some water up then spit it slowly in as you mix, poke the mixture in the hole and install the bolt. Climb the next day but they aren't real strong, I tested a series and you need a week to get to the standard with my 6x80 twisted bolts. Good is the stuff just keeps getting better for a month and lasts forever. Bad is you only have a couple of minutes so do each hole at a time hanging on the rope.

Resin capsules are cheap, fast and the strongest system, the way to go.

Jim Titt wrote:

I've installed about 20 bolts (two routes) with quick-setting cement, it's quite entertaining! Taught by a master of the trade, he'd bolted maybe 1000 bolts and climbed 8b.

You need a dessert spoon bent to more of a scoop shape, a mixer wire and a prodder to get the stuff down the hole, a dentists mirror ground smaller to go in the hole is what we had. Then a black-powder pouch to dose the cement (or guess) and a water bottle and a plastic tube. Dose the cement, suck some water up then spit it slowly in as you mix, poke the mixture in the hole and install the bolt. Climb the next day but they aren't real strong, I tested a series and you need a week to get to the standard with my 6x80 twisted bolts. Good is the stuff just keeps getting better for a month and lasts forever. Bad is you only have a couple of minutes so do each hole at a time hanging on the rope.

Resin capsules are cheap, fast and the strongest system, the way to go.

Jim - any insight into using these Dewalt Capsules with your say 6x80mm or 6x100mm?  They're 3/8in but for 88mm hole depths.  The 1/2" size is LONG at over 4 1/2"   I've got a few anchor replacements where it's only 2 bolts going in a WAYS from the road so would be nice to just use something like this.  Anyone else have insight here?  at $2.50ea vs a $3 nozzle plus glue the costs seem within the margin of error for small projects...   I suspect there's some trial and error to get the capsule volume to right bolt correct.

Dewalt Capsules

Specs PDF

Fishy Boi wrote:

Hello timothy,

Thank you for your advice.

I believe I will just go with 1/2" threaded rod to be certain. For the first 2-3 bolts anyways for removability due to access issues.

The nice thing about using Hilti anchor rods is that there is little question about its quality.

May I ask what glue you are using with your threaded rods? And what drill bit diameter you are using with the 1/2" rods?

Thank you

9/16 (14mm) is the correct drill diameter for 1/2 rod. I use the A7+ because I can buy it locally and check expiration date. I usually do glue work in cooler weather. The working time is very limited in hot weather with that Acrylic.

I have been only using 7/16 rod as of late. It is crazy strong and is perfect with a half in hole. Hangers with 12mm holes  are a good fit. 

I wouldn't be a fan of the big rod for a protection bolt since the nut can interfere with the carabiner on many hangers. Maybe the Fixe hangers (or similar) would be the best for a big nut.

Have you considered using a sleeve bolt like a Powers bolt? When you remove the bolt and hanger the sleeve stays in the hole and would be hard to see by a non climber.

1/2 Powers Bolt uses a 3/8 bolt which would fit your hangers. You discard the washer that comes with the bolt when you use it that way.

mattm wrote:

Jim - any insight into using these Dewalt Capsules with your say 6x80mm or 6x100mm?  They're 3/8in but for 88mm hole depths.  The 1/2" size is LONG at over 4 1/2"   I've got a few anchor replacements where it's only 2 bolts going in a WAYS from the road so would be nice to just use something like this.  Anyone else have insight here?  at $2.50ea vs a $3 nozzle plus glue the costs seem within the margin of error for small projects...   I suspect there's some trial and error to get the capsule volume to right bolt correct.

Dewalt Capsules

Specs PDF

Please give us feed back on these if you try them! Seem like a great solution to small remote projects.

Hello timothy,

Thank you again for the advice!

My concern with the powers is that if I remove the bolts for a time and I were to leave or otherwise be indisposed, it will be harder to put those bolts back in commission when access is granted again. 

While with threaded rods it is just a matter of a nut and hanger, which can be both positive and negative.

Also I am uncertain about leaving open holes over longer periods of time, especially on lower angle routes where dirt and debris might accumulate. With exposed threads it is easy to brush off and lube. I am not familiar with how easy it will be to clean the mating surfaces on a powers bolt that has been placed and removed.

As to the nut and threads interfering, if I can get the exposed thread the same length as what would be exposed on a 1/2" expansion wedge bolt. This should have the same risk I believe?

I have been using fixe hangers for all my 3/8" and 1/2" bolts.

One thing I do like about threaded rods is that one can go to fairly deep placements if I think it will be needed.

Thank you

timothy fisher wrote:

1/2 Powers Bolt uses a 3/8 bolt which would fit your hangers. You discard the washer that comes with the bolt when you use it that way.

No one should he using 1/2" Powers bolts with a 3/8 hanger, and you should 100% be using the washer. This was realized many years ago, and only a percentage of the bolting community got that memo. 

If you use a 3/8 hanger, youre effectively only using the bolt itself, and not the sleeve too, to take all of the force of a fall. This is not how it was designed to be used. And removing the washer means you'll likely see spinners before they would have occurred with the washer installed. 

P.S. thanks Jim. Concrete sounds like a tough way to go.

Matthew Jaggers wrote:

No one should he using 1/2" Powers bolts with a 3/8 hanger, and you should 100% be using the washer. This was realized many years ago, and only a percentage of the bolting community got that memo. 

If you use a 3/8 hanger, youre effectively only using the bolt itself, and not the sleeve too, to take all of the force of a fall. This is not how it was designed to be used. And removing the washer means you'll likely see spinners before they would have occurred with the washer installed. 

P.S. thanks Jim. Concrete sounds like a tough way to go.

HMMM I believe you are quite incorrect about this.  Not just a little. The 2 3/4  long  1/2" Powers bolts that I use most have a plastic sleeve at the surface of the hole. The sleeve plays no real part in the shear strength of the bolt.  The solid shank of the 3/8 bolt is where the shear strength of the bolt comes from. I have been placing these things for 31 years.  The stainless ones. Don't have a spinner problem. You are not the only one who has this opinion, but it is not based on fact. 

Well, Fixe and a ton of other industrial reps disagree with you, and have for a decade. Just because you've been doing it wrong for 31 years doesn't mean you're right. The sleeve gets placed through the hanger too, and it doesn't just sit inside the rock, allowing the bolt to contact the hanger directly. Call Fixe if you dont believe me. They sold 3/8th hangers with 1/2" bolts for a long time before realizing that was wrong.

Matthew Jaggers wrote:

Well, Fixe and a ton of other industrial reps disagree with you, and have for a decade. Just because you've been doing it wrong for 31 years doesn't mean you're right. The sleeve gets placed through the hanger too, and it doesn't just sit inside the rock, allowing the bolt to contact the hanger directly. Call Fixe if you dont believe me. They sold 3/8th hangers with 1/2" bolts for a long time before realizing that was wrong.

Climb tech who also sell Dewalt Powers agree with me. I witnessed the argument between Chis and Kevin at the first "Future of fixed Anchor" conferance.  Kevins argument has always been just as weak as yours is. 

If you have something in writing from Dewalt on how to use these for climbing I would love to see it. I dont think they are going to do that. 

The only sleeve that would go through the hanger on a 2 3/4  5 piece is the plastic one. I prefer the hanger to load the bolt directly. I will use a 3/8 hanger for a 3/8  Powers Bolt just because few hangers are availible with 5/16 holes. 

timothy fisher wrote:

Climb tech who also sell Dewalt Powers agree with me. I witnessed the argument between Chis and Kevin at the first "Future of fixed Anchor" conferance.  Kevins argument has always been just as weak as yours is. 

If you have something in writing from Dewalt on how to use these for climbing I would love to see it. I dont think they are going to do that. 

The only sleeve that would go through the hanger on a 2 3/4  5 piece is the plastic one. I prefer the hanger to load the bolt directly. I will use a 3/8 hanger for a 3/8  Powers Bolt just because few hangers are availible with 5/16 holes. 

3/8th bolts do use a 3/8th hanger. It's the 1/2" that need a 1/2" hanger. Do what you want, im not trying to win an argument, it just is what it is. If you want to keep installing your bolts incorrectly, then go right ahead.