What Is A Climbing Bolt + Should You Trust Your Life To One?


Bolts forever changed climbing. Their introduction in some areas led to fistfights. Now, most climbers wouldn’t think twice about trusting their lives to one in a fall. But should you?

What Is A Climbing Bolt?

A bolt is a metal anchor that is permanently attached to the rock. It allows climbers to quickly clip their rope to the wall using a quickdraw. Most “bolts” are actually made up of two pieces: a literal bolt, and a hanger that is used for the actual clipping.

The common term used for the whole set-up is just the singular bolt. Many people use the slang “clip” to refer to the bolt. For example: “There’s a hard move at the third clip”.

There are a few designs with different metals used depending on the area. Modern bolts are pretty rugged and similarly made, but for a long time bolts were homemade, or bought from hardware stores as cheaply as possible.

Rock Climbing Bolts Explained – Why Use Bolts?

Bolts are a fixed, long-lasting way of safely attaching yourself to a wall. They’re regarded as being incredibly safe, and most climbers will happily take fall after fall on the same bolt for years.

Using bolts means climbers can push themselves as hard as possible without really having to worry about their protection in the rock failing. It makes climbing more of a sport than a dangerous adventure.

What Is A Climbing Bolt - Clipping Bolts Using A Quickdraw
Clip one end of the quickdraw to the bolt, clip your rope to the other – easy!

So, climbing by clipping a quickdraw into bolts is called sport climbing. Climbing without fixed protection (aka bolts) is called trad climbing. While many will do both, most climbers have a preference for one. They also have different cultures and ethics that apply to creating new routes and claiming ascents.

Read more
What Is Sport Climbing?
What Is Trad Climbing?

Are Climbing Bolts Safe?

Yes and no. A properly installed bolt can last for years of repeated falls and poor weather. There are things to look for we’ve listed below. As with everything in climbing though, it’s up to you to make an informed decision on what you deem “safe enough”.

Types Of Climbing Bolts

There are two main types of modern bolts used in climbing – expansion bolts, and glue-ins. Modern bolts are either 1/2″ or 3/8″ thick in the US, or 12mm and 10mm in the EU. Suggested thickness depends on the rock, the method of bolting, and how much money the bolter has available.

Most bolts are stainless steel of different grades, with 304 common but 316 recommended as being higher quality. In some sea cliff areas (Thailand as a great example), steel bolts won’t last long and titanium bolts are required.

Different Types Of Climbing Bolt - Glue in staple, single leg, expansion bolts
Most of the modern climbing bolts you’ll (hope) to see out on the rock

Expansion bolts are normally made up of a hangar, and a bolt made of multiple pieces. There is a metal sleeve over the length of the shaft. Once hammered into the rock, the bolt is rotated, which forces the sleeve to open up at the end by the expander cone.

This pushes the metal sleeve outward, wedging into the rock. It works much like a wall plug you might use on a screw to fix something into plasterboard. With a soft rock like sandstone, the bolt should be longer.

Glue-in bolts are much simpler and work like the name. You can get rounded U-shape staple-like ones that need two holes drilled. Most modern glue-ins use a single hole. The design either has a single, bonded leg or a twisted leg that does the same job.

They look like the letter “P” with a long tail and come in lots of variations, mostly all in one piece. Titanium bolts are nearly always glue-ins. There are lots of different glues with different strengths, drying times, and suggested rock/metal uses. Most are two parts, using an epoxy and a hardener that need to be thoroughly mixed and used at specific temperatures.

There are also hundreds of types of anchor set-ups for the top of the climb to lower or rappel safely. Most use a couple of bolts connected by a chain, and a couple of rings or chunky carabiners to lower from. That’s for another article.

Indoors, climbing bolts are much simple. The hanger is normally exactly the same as you’d see outside, but the bolt is just a long stainless steel bolt. It is drilled directly into the same metal t-nuts that holds are drilled to.

Don’t take any of this as an instructional guide on how to bolt. If you’re interested in putting up new sport climbing routes or anchors, get involved in your community and find a friendly bolter to get mentored by. Bad bolts can lead to serious injury and death.

Why Are Bolts Controversial?

Ethics in climbing are a difficult and still widely debated topic. “Clean climbing” was always a big consideration. For many that used to mean leaving nothing in the rock after topping out a route, as well as leaving the area how you found it.

For many though, falling on a route meant lowering right to the bottom and trying it from the start. Falling and carrying on, hanging on a rope to rest (hang-dogging), or rappeling in from the top to check it out before trying were all big no-nos.

Plus, the danger of falling and pulling out a piece of protection was deemed an integral part of the lifestyle. Bolting led to an entirely new way of doing things. Now, people would practice, fall repeatedly without worry, and the only important thing was how hard the route was.

What Did Climbers Use Before Bolts?

The things we put into the wall are called pieces of “protection”. Back in the day, the common practice was to take a hammer and pound pitons (thin metal wedges with an eyelet) into the rock.

Later, nuts (the first were literally the metal nuts used to screw onto bolts) and other chocks were used by wedging them into crevices and cracks. These are passive types of protection that sit in the rock in places where they hopefully won’t pull out.

Then, active protection in the form of cams became the norm. A cam is a clever mechanical bit of gear that can be placed in a wider range of spaces. You pull back on a trigger to make the cam slimmer to place it in the rock. When you release the trigger the cam expands.

Springs push the lobes out to wedge it into place. Pulling the cam or falling pushes them out further against the rock, which actively protects the falling climber. Cams and nuts are the main types of protection used in trad climbing.

How Are Climbing Routes Bolted?

Most of the time, bolters will scout out a new wall from the ground and look for good lines of possible holds. After that, they’ll figure out a safer way up to the top (via a hike or another route). An anchor is set up then they rappel (abseil) in from the top with a grigri and other gear.

This is the safest way to do it, but some areas’ ethics insist on a ground-up style of bolting on lead! That means placing a bolt with a drill or hammer while resting on traditional gear or hooks.

Ondra bolting ground-up – this isn’t common in most areas.

“Cleaning” a new route normally involves a lot of dirty work. First, the bolter will find any loose rock that might fall off if pulled on with someone’s entire body weight. This will be pried off with a crowbar or knocked off with a hammer. Once the climb is safe enough they’ll start looking at places to put in bolts.

A hammer is indispensable as a bolting tool for many reasons. If you ever see anyone up on a route knocking on the wall, they’re listening to the sound it makes. A high pitch means the rock is reasonably solid, low pitch means there might be a cavity behind the wall.

Choosing bolt placements is part science, part art. The bolts need to be in good rock, and not too close to cracks or seams that could break. They also need to be close enough that the climb is safe but not too close that they’re detracting from the climb.

Then they’ll ideally be easy to clip from decent holds, in a straightish line to avoid rope drag, and in places that won’t cause carabiners to rest on an edge. It’s a hell of a lot of work, and most bolters go into their own pocket for the gear.

Support your local bolt fund!

How Are Bolts Put In?

What Is A Climbing Bolt - Fixe expansion bolt installation
Expansion bolts are hammered in first. Then, a wrench is used to expand the metal “collar” into the rock to secure the bolt

Modern bolting is almost always done with a big, cordless hammer drill, while the bolter hangs on a rope secured at the top of the route. They’ll rappel in on that rope, and can “jug” up or lower down.

Once they’ve found a decent place for a bolt and tested the rock around it, a deep hole is drilled. This is then cleaned with a wire brush and a tube to blow the dust out.

If it’s an expansion bolt it’ll be hammered in with the hanger attached. The nut on the end is tightened and the metal jacket around the bolt will expand into the rock to secure it. Once it’s tightened up to the right torque, that bolt can be used straight away.

For glue-in bolts, one or two holes are drilled depending on the type. Then a two-part glue is mixed and squeezed into the rock and the bolt is placed. The glue needs to cure properly and be set at the right temperature before being used.

Do Bolts Break?

It isn’t common at all for bolts to break, but it does happen. Serious injuries and deaths have occurred because of bolt failures. Things that have caused bolts to break or pull out include: –

  • Poor rock quality leads to the whole chunk of rock pulling out
  • Bolts placed too close to cracks and faults
  • Poorly placed bolts – Not torqued enough, overly torqued, not long enough
  • The wrong type of bolt used for the area/rock
  • Bad or improperly cured glue
  • Corrosion because of the wrong metal or two different metals used corroding each other.
  • Hanger is not fully attached or a loose bolt-head coming off (spinner)
  • Sea water in the air near cliffs corroding metal – Can be hard to spot
  • Old, thin bolts
  • Home-made or hardware store bolts not rated for climbing
  • Quickdraws or carabiner placed incorrectly – Falling can generate enough force to break the bolt, more commonly the carabiner on the quickdraw would break
  • Bolts made with the wrong steel strength – Often Chinese steel
What Is A Climbing Bolt - Bad Bolts

Top three from left to right: An old, home-made hanger and bolt on a classic route (source); Bolt didn’t attach correctly (source); Poor quality steel hanger (source)
Bottom row from left to right: Incorrect metal used for the area leading to rust. Replaced with titanium (source); Cheap hardware store bolt placed by amateurs (source); Bolt placed too close to edge of rock (source)

How To Spot A Bad Bolt

Bad bolts can be tricky to spot, and it’s really up to you to figure out what risk you’ll accept.

  • Rust is the most obvious sign of a bad bolt. If water and moisture enter the bolt hole, frozen, then thawed, the hole may have expanded and be unsafe. Even a little spot of rust on the outside could mean the whole bolt is ruined. Rust is also a sign of mixed metals – a no-no for bolts. However, a little rust might not mean the bolt is completely unsafe.
  • Flaking metal is a sign that the bolt is unsafe. In certain humidities – especially on sea cliffs – stainless steel bolts can corrode fast. A Slight flake can mean the internal metal is completely compromised and unsafe.
  • A loose hanger is fine and can be tightened back on. New climbers are often freaked out by a hanger that isn’t totally tight, but it happens and you are expected to tighten it up if you see them. Many climbers even take a little finger-wrench for the job. Check out the Metolius Torque Nut Tool which does the job.
  • Loose bolts are a different story. If the bolt moves about in the hole then it’s probably unsafe. If it rotates or pulls out at all, avoid using it if possible.
  • DIY or hardware-store bolts used to be the norm 40 years ago but shouldn’t be trusted now. If you see newly placed bolts that just look “off”, don’t trust them. Take pictures, check with local climbing groups, and find out if the bolts are safe or should be chopped.

Is A Piton A Bolt?

A piton isn’t a bolt, but it is a type of fixed protection that generally stays in the route for years. Pitons are simple metal wedges that are hammered straight into the rock and can be used immediately. Falling on a piton isn’t recommended, but if they’re the only option then you should clip them.

Some routes that were established with pitons will get bolted, whereas other areas try to keep old pitons or just replace them when they’re obviously too rotten to use. Climbing ethics vary by area when it comes to “upgrading” gear, and it’s a common point of contention.

What Does Tape On A Bolt Mean?

You may sometimes see tape (often red electrical tape but not always) on the first bolt or two of a climb. It’s most common in new areas or where the bolts are new. If you see this, do not climb the route.

Tape usually means the route is not ready to be climbed, either because

  • The route is new and needs work to make it safe – The could be loose rock to be cleaned, a few bolts might have out to be in bad rock and need redoing, or the glue used takes time to set properly.
  • The bolter is still working the route and wants the first ascent – This is the accepted etiquette. They set the route, it’s theirs to work on until it’s done – aka a closed project. There isn’t any set time limit but if they’re just not getting it, the bolter will either let a friend get that first ascent or open it up. Don’t be tempted to “try” the route or do it without claiming an ascent. It’s not cool.
  • The route is off limits – Sometimes an old route might have a huge loose block that’s finally peeling out, and the local community is figuring out how to make it safe. Sometimes there are bird nesting restrictions and people aren’t checking access before going to the crag.

Whatever the case is, don’t climb routes with tape on the first bolt. Sometimes a padlock is put through the first bolt, or even better a note. However, we have to accept that the less “clutter” on a route, the better it is for others that want to enjoy being outdoors.

Chopping Bolts

When bolts were first introduced, they were hugely controversial. Leaving a bit of metal in a natural area will always detract in some way. The style in which routes were now climbed was the main problem for old-school climbers.

This friction led to people either chopping the bolts off completely, hammering the hangers flat, or otherwise destroying the bolts. For many years there were back and forths over the use of bolts. Nowadays, most areas have specific ethics that dictate whether bolts are allowed.

For example in the UK, disused limestone quarries are seen as mostly fair game to bolt. The rock quality tends to be bad at holding trad gear, and the area isn’t completely “natural” as it was artificially dug out.

However, place a bolt in the stone of the Peak District and it will be removed the next day plus you’ll be shunned from the community, if not worse. Hard Grit is a classic film about the area and the “bold” ethics that forgo bolting.

In some areas, there are mixed ethics depending on the rock. If a climb has a continuous crack that can be protected well by cams, bolts aren’t the first answer. If there are blank sections and no good place for a natural anchor at the top, a couple of bolts and a bolted anchor might be accepted.