“Some slip right on in, some you have to force, but either way it is just a sticky mess”
The Bolting Bible
The Book Of Glue In Bolts
Welcome to our free course as our way of contributing to the bolting community. It's nice to understand what you are clipping and trusting with your life, even if you never plan on installing or removing bolts. Also, if someone is going to spend their time and money to bolt something, I assume, they probably want to do it as good as possible. Hopefully theBolting Bible gives you the tools you need to do a great job. Get it?
Our courses are A-Z content in blog format, glued together with an over arching blog we call a text book. A blog format is easy to read, easy to update, and easy to translate. Be sure to begin at the TEXTBOOK and at the end of each episode we'll point you to the next.
Glue in bolts are a great option for most placements but installation is trickier. They are stronger, last longer and are more convenient to use (not install) since many don’t require hangers. It is thought that the adhesive can help seal the bolt preventing corrosion inside the hole. However, the holes have to be really clean, the glue has to mix correctly AND fill up the entire hole… all without getting glue on your favorite shirt. Also, the bolt isn’t adjustable later so it better be right the first time. Longevity and minimal maintenance requirements makes them a great option, especially in soft or layered rock, so let’s go over what you need to know so you can do it like a pro.
You could just bolt anything inside of a hole, but if you are reading this, we assume you are thinking long term and want to do it right. It is NOT recommended to use mechanical bolts with moving parts like we described in the last section. You get the worst of both options. The glue wouldn’t grab the right parts, like sitting on the sleeves and not the actual stud, and the mechanical parts get gummed up by the glue and aren’t free to do what they need to do. And any properly placed mechanical bolt is going to fit the hole so tightly, there wouldn’t be any room for the glue and therefore push it all out. There are bolts specifically designed for glue, so let’s go over those options.
U shape bolts
Also called staple bolts, these are almost never used in highlining and rarely used in climbing, as they require two holes and have twice the impact. And consider that the 2 legs rarely share the load so you don’t necessarily get 2x the strength. If one leg goes, so do you. AND… when holes are drilled that close together, it could weaken the rock. It also requires more effort to line up the two holes. The benefit to these is that they can test stronger when being pulled straight out than the P shape bolts. These have the potential for one side to open the gate on carabiner if things are pulled around, probably the main reason these are not used on climbing crags, but rather via ferratas where the hardware is fixed. Please don’t buy any ol’ U shape bolt from the hardware store! If you must use them, please use Titan’s or (another climbing specific bolt) because they are very corrosion resistant and rated for 15kn with an MBS rating of 30kn but commonly break above 50kn.
Solid leg glue in bolts
Climbing-specific glue-in bolts generally have an eye designed to sit outside the rock so they don’t need a hanger. These are nice because you can thread it with a static rope eliminating the need for quicklinks. The single rod, or solid leg bolt, has grooves or notches on the shaft for the glue to have something to grab.
This is critical as epoxy glue doesn’t adhere to stainless steel very well (or at all), but stainless is critical for longevity. Solid legs are either welded or forged. Welds aren’t ideal, they are a potential weak point for strength as well as corrosion resistance.
In BoltBusters we have found Fixe’s welded glue ins fail at consistent values but the Crux Monster, while all super good enough, are all over the chart. You can see some home made ones done in this VIDEO. We don’t recommend you make them!! It is important to have some
thing that is thoroughly tested and standardized is important but the process is neat.
“P” shape or Continuous Rod glue in bolts
Another option is a continuous rod that is like a U shape bolt, except it is “P”
shaped, so it shares one hole like the everlasting titanium Titan Eterna bolts, the bomber Twisted Leg Bolts, and the popular wave bolt. Some of these bolts require a hammer which is unusual for a glue in. The wave bolt requires a lot of hammering as it fits tight like a compression bolt, and Titan’s Eterna and Bolt-Product’s Twisted leg bolts only need a few taps to fully seat them. The reason for this is so the bolts don’t fall out before the glue hardens when installed by climbers in vertical or overhanging rock. The titanium bolts will last longer than you will because they are significantly more corrosion resistant than 316SS, which is fine in normal conditions.
We are fortunate to have them available as a glue in option, as titanium is still a bit too expensive to manufacture as a mechanical bolt. The glue holds all these bolts well from either the notches in the legs or the bent/twist pattern which snuggles that bolt in the security of all that gooey glue.
This is literally a threaded rod glued into a hole. It is also important to use stainless steel (SS) and not cut the end that will be exposed to ensure you have really good threads for you to screw your nuts. Cutting exposed ends also risk leaving iron deposits embedded into your precious SS that can cause corrosion, but that is most likely fine if it is embedded in the bottom of a hole surrounded by glue. Many cut the bottom of their rods at an angle so it helps prevent the risk of twisting the bolt in the cured glue (like if the nut seized on the threads and you were trying to remove it with a lot of pressure). “Why cut it at all?” you ask. So you can buy a 12” rod and cut it in half and have two rods. Threaded rod gives the option of using hangers, removing hangers, or turning hangers for multi-use, such as different highlines that go in different directions.
You can also drill a hole in a hand sized rock, glue a nut in the hole and screw the rock onto the threaded rod to hide bolts in sensitive areas. The risk with threaded rod is that the threads can get damaged, especially if removing hangers is frequent and then you are left with a useless stubby sticking out of the rock. These don’t save you any money as you need to buy a SS nut, washer and hanger to match the metal you are using. These also have been used to glue death flakes to the cliff that you can’t seem to remove. Fully bury the threaded rod and throw a little sand over the exposed glue spot and you have a bomber-ish flake.
Glue In Bolt Buying Guide
● Solid legs come in 8mm, 10mm, and 12mm. The large 12mm bolts have a thick rod which means better bend radius for ropes. Popular among highliners who use threaded rope for anchors. Size of the bolt is the size of hole required. Comes in 304SS and 316SS. Bolt buster break tests have these welds breaking all over the board but plenty strong enough and I recommend them.
● Twisted leg series is a continuous rod twisted to give the glue a shape to hold onto and allow more glue in the crevices. The 6mm rod (12mm or ½” hole) has a very similar feel to a wave bolt and is hard to tell the difference after they are installed. The 8mm rod requires a 16mm or ⅝” hole and is very very hard to break in bolt busters. These also come in 304SS and 316SS. There is also a large eye 8mm version.
● The USA distributor is Team Tough but has a limited selection listed online. If you contact them, they can source most of the products listed on the main Bolt Products site.
● General thoughts: Jim Titt makes great bolts. His website was probably made in the 90s and rarely updated but a lot of the bolting bible came from the information found on his website. They are based out of Germany. Jim is very active in the bolting community contributing extensively on Mountain Project forums.
Believe it or not, bolting companies are not lining up to sponsor us; mostly because there is no money in such a niche industry. $1 per episode helps a ton and so does grabbing MERCH if something grabs your eye. Lots of designs and options.
● Martin Roberts is an expert on Titanium and made the first certified TI climbing specific bolts. The continuous rod has no welds and is ideal for corrosive environments like near the ocean. They are more expensive than stainless naturally but not if you consider these could last 200 years. They did great in our Bolt Buster tests. He also sells Titanium U bolts and other titanium quicklinks/rings for anchors. Titan is based out of the UK. Martin has been very helpful in this Bolting Bible project.
Tonga Rock also sells a Titanium bolt that may be sourced from Alibaba.
They are made with a TA2 grade titanium and some have been tested to12kn without deformation. Titan Climbing professionally manufactures and rigorously tests their bolts but Tonga Rock’s bolts are an alternative. Contact SOPHIA if you are interested. Minimum orders are 100 bolts, $7 a piece unless you order a 1000, then it’s $5 each and 3 week lead times. Welcome to Alibaba!
● These win the popular award, are plenty strong enough but I’m not that fond of them. They require a special tool to hammer in and spin as you hammer them so you have to hit them sideways after they are solid in the whole.
The tool isn’t just to keep a carbon steel hammer from leaving iron deposits on your stainless bolt, but it puts the pressure of your smacking on the bottom of the eye which is stronger than hammering the top in. We have bent these installing them during our Bolt Buster tests. The force required to drive them in can cause glue to squirt out leaving air pockets behind. Drill your hole bigger than they recommend to solve some of these issues.
I don’t recommend running a rope through them as the bend radius isn’t very large, reducing the strength in your rope. They broke all of our soft shackles before the bolt broke! Some people think the tight fit means they are bomber and the glue is just added strength. We pulled them out with no glue at 1.5kn to 2kn in tension (straight out) in SAMPLES 9 to 11and got 19kn to 27kn in shear in SAMPLES 47, 72 and 73. Pretty impressive but make sure the glue is doing the work since we can get 40kn-ish properly installed like in SAMPLE 31. Tip: wallow hole or use a 14mm drill bit (slightly bigger than ½” or 12.7mm) and they will be easier to get in and you can skip the fancy hammer tool and use a rubber hammer.
● Manufactured by ClimbTech
● Fixe Hardware is the US distributor for the Spanish Company Fixe.. While you may see products in their proprietary PLX HCR steel they are currently producing bolts in 316L SS.
There is also talk of a Titanium staple. They have a glue in with no name that we keep calling “bell shaped” with an MBS of 35kn that gave us great results in Bolt Busters (45kn to 63kn in tension). It has a weld but is buried under the glue when notched. Notching these bolts hides the weld which is thought to reduce corrosion as well as preventing a pinch point to trap ropes. The large bend radius is great to thread a rope thru for highline anchors.