top of page

Bolting For Highlining

Funny phrase here

The Bolting Bible

Bolting For Highlining

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 the Bolting 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.


Going All Natural

Like any good hippie, going all natural is more fun. In highlining, if we can string up our massive bag of 1" wide plastic across the sky with no bolts used, that is what we call "all natural" rigging. It's held as a higher form of rigging but it isn't rocket science how we do it. Wrap a tree or rock like you would to slackline in the park or place a whole bunch of climbing trad gear and get good at equalization.

Rigged off cams, backed up to the rappel rope

Highliners often times play on top of the cliffs and if we place 3 or 4 bolts on the top where a lot of people can see them, it can negatively affect access. Especially if there are multiple lines in one area. The Fruit Bowl in Moab is now a highline destination but notice it has hundreds of bolts littering the tops of the cliffs. You can't do that just anywhere today.

It is a higher form of rigging to take with everything you came with. Aim to rig highlines all natural and really consider if that spot needs bolts before installing them. Also, know your area first to see if you can legally install the bolts!

You can see many examples of different ways to rig in our HIGHLINE RIGGING PLAYLIST.

Sharing Space

It's less of an issue today, but climbers can get upset about highliners using their bolts. Oftentimes, climbing anchors are in the perfect spot to rig a highline and from a safety perspective, we are not damaging the bolts. That was an argument for years! It's not in case you were wondering. But we have to share and figure out how to do that without pissing anyone off. Be kind, communicate clearly and consider not highlining in a spot during a busy time if it is preventing climbers from enjoying that space as well.

Eichorn Pinnacle has bolts on top for climbers to rappel. We can just wrap the boulder on top as our anchor instead.


Highliners play with more force than any other sport. Climbing gear may see 8kn sometimes in gnarly factor two falls but it's short and rare. Highlines, especially freestyle or > 1 KM long highlines are constantly playing at 8kn. High tricklines can be even 12kN! Most highlines are 2-3kn when they are tensioned and 3-4kn when are walking on it and 4-6kn when you whip.

How much can a bolt hold? Minimum 20kN. In the Book of Numbers, you can see most of them are in the 30kn-40kn range, and some we can't even break because the hanger breaks first at 50+ kN. Now, you can't put short 3/8" (10mm) in sandstone and cyclically load it to 8kn without it failing so it's important to follow good bolting principles taught in the Bolting Bible but if you do a half-decent job it is super good enough!



There are a couple of deserts on earth where a zinc-plated bolt will last about 50 years, but aim to install hardware that will last longer than you and put in stainless. No one wants to highline on rusty bolts. The bolts we replaced in Yosemite were barely 20 years old and they were very rusty and even the bolts replaced in Moab's desert were rusty. Also consider that if they are installed on top of a cliff, the hole will hold water even if it doesn't rain that often. And of course, use Titanium if rigging near the ocean.


How do you drill a straight hole? Go read the Book of Holes for those details. Let's talk about where are you going to put the bolts. The goal is that your master point is barely over the cliff edge so you don't risk abrasion but it's not a PITA to reach way out to work on the master point. In Yosemite with good rock, the bolts are fairly close to the cliff edge so you tie a bfk and it sits right on the edge. However, the bolts in the sandstone at the Fruitbowl are several meters back because that is where the good rock is and then everything needs to be extended.

How many bolts do you need? Two is redundant, and 3 is awesome. Installing 4 and 5 bolts must be a very rare circumstance of shit rock because most of the time, 2 bolts are holding most of the force anyways since it is difficult to properly equalize a cluster of bolts.

What is the best pattern to place your bolts? The bolts most in line with the master point see the most force and the bolts closest to the master point see the most force. If you set the center bolt in a 3 bolt pattern back further than the outside two bolts, they will be very close to truly equalized. If you can equalize 3 points well, then no bolt is ever going to see more than 3kn giving you a 10:1 safety ratio for each anchor point.

Old School Bolts

1/2" x 6" zinc plated wedge bolts in Yosemite

Back in the day when the forces were more of a mystery, many highliners put in big bolts and lots of them. Some old school bolts were big 5/8" (16mm) wedge bolts with 2-3 chain links sitting on a stack of washers as the hanger. Terry Acomb established the Fruitbowl area and these were bomber and affordable. Many of them have been replaced with the new stainless glue in standards for that area by Balance Community for GGBY. Many bolts in Yosemite were also much bigger wedge bolts than climbers would ever need but it was a mixed bag of what was put in. They are all now Fixe 1/2" glue ins so the rope can be directly threaded into them since lightweight is key in Yosemite.

Terry bolt in action here

Today's Bolts

Even though a 3/8" (10mm) mechanical bolt is ok, it's standard to use 1/2" (12mm) bolts. The type of bolt doesn't matter for highline safety but depends on the quality of the rock. Also, it's not only about ultimate failure but when a bolt starts to bend. A wave bolt glue in is strong and is in a 1/2" hole, but the 6mm metal bends at forces you can get in a highline like in this EPISODE. If you are going to use a 1/2" glue in, use a welded type so the metal is truly 1/2" and not 6mm folded in a P shape.

It's ideal to be able to thread a rope directly into the anchor since many anchors are built with rope bfks. Any solution for this is compatible with delta quick links + spansets which is another way of rigging. Glue in bolts are all made of some sort of round stock metal so these solve that problem and are bomber in any rock and don't have hangers for people to steal. There are a handful of hangers out there that can have a rope directly threaded through them if you want to use a mechanical bolt.

A rare but clever solution to keep bolts hidden was to drill a big hole in a small rock and carefully glue a nut to the inside of the hole, keeping the threads clean, so you could screw on the rock to the bolt. Just remove rocks and nut on a hanger when you want to use it!

Get Started In Highlining

We have Highlining 101, a free course on our website to help anyone learn everything they need to know how to use a highline that is already rigged. Go to our COMMUNITY page to find people and places to slackline. It was a massive effort by ISA and HowNOT2 to create that database and get it on a map but it's to help anyone new get plugged into our community. It also has a calendar of festivals, comps, and education events.

Sexy Photos

Just to make highlining look more fun than it really is.

10% Supports HowNOT2

Climbing, Caving and Canyon Gear

& Over 30 Bolting Products


HowNOT2 Contribute

If you see a typo, or see a resource online we haven't linked to, or have something to share, we'd love to add it. If you are contributing a video, image, or words, please be kind by delivering something ready to add and tell us where you think it best fits.

What's Next?

This course is free but not free to make.

If it really helped you, please consider SUPPORTING US.