Set up a climbing route with expansion bolt

Would you like to set up a climbing route with expansion bolt? Then bolting.eu is the right place for you. Because we are the experts when it comes tobolting a climbing route. We will provide you with comprehensive information below. So that you can establish a climbing route with bolts yourself.

Firstly, the advantages of this fastening system. Secondly, of course, the disadvantages. Thirdly, we systematically list the work steps. Fourthly, we present the materials required.

Would you like to use glue in bolt? Then read our article“Setting up a climbing route with glue in bolt “.

The picture shows a situation that fits the theme "Establishing a climbing route with bolts". A pile of expansion bolt with mounted lugs lies on a granite slab.
expansion bolt are an integral part of climbing culture. The majority of all routes are secured with this type of fixed point. Photo: bolting.eu

Setting up a climbing route with expansion bolt – the advantages

There are several reasons in favor of expansion anchors. To put it simply, installation is very simple. It is also very quick. And on the other hand, the costs are low. In addition, the fixed point can also be loaded immediately.

Time factor

Putting in the expansion bolt is quick. It often only takes a few minutes and all the work steps are done.

Therefore, establishing a climbing route with bolts is a clear decision.

Simplicity

The processing of bolts is relatively simple. On the one hand, the entire process involves very few steps. And secondly, the way the expansion hooks work is very simple. So all in all, you can do very little wrong.

You can find the individual steps in the article “Setexpansion bolt “.

Set up climbing route with expansion bolt -costs

The combination of expansion bolt and bolt hanger is relatively inexpensive. The price is approx:

  • zinc plated steel: € 2,-
  • A2 steel: € 3,-
  • A4 steel € 4,-
  • PLX / Duplex steel: € 6,-
  • Exception HCR steel: € 30,-

In addition, the (thin) SDS drill bits required are relatively inexpensive.

The components for processing and the drill bits themselves are considerably more expensive! glue in bolt themselves are considerably more expensive!

Immediately loadable

Bolts are so handy because you can load them straight away. This is extremely helpful in some situations.

Firstly, when “bolting in the lead”. Secondly, when bolting in overhangs. Thirdly, when installing lower off climbing anchors. And fourthly, when setting up abseil routes.

The picture shows a climber on a rock face. He is about to set up a climbing route with expansion bolt and is therefore leading up a slab. He is looking straight back and raises the drill as if in salute.
One of the many advantages of expansion bolt. You can also bolting in the lead! Photo: bolting.eu

Setting up a climbing route with expansion bolt – the disadvantages

Bolts do not only have advantages. You should therefore be aware of the following six facts.

  • Rock subsoil
  • Explosive effect
  • Torque
  • Influences on the components
  • suitable bolt hanger
  • galvanic corrosion

We want to explain the individual points in detail again.

Rock subsoil

Expansion anchors have enormous holding forces and breaking loads (approx. 20 kN). These are far higher than the forces from climbers’ falls (approx. 4-6 kN). So before a bolt itself fails, the rock base is more likely to break. It is therefore extremely important to check the quality of the rock. This is done with the so-called “hammer test”. If you want to open up a route with bolts, you need to know what they are.

To do this, “tap” the rock at the desired point with a rock hammer. High and “firm” sounds are good. Deep and “dull” tones indicate cavities. In such places, expansion bolt cannot be set.

Only solid and continuously compact rock is suitable for the installation of expansion bolt.

Gerhard Schaar – Founder bolting.eu

Soft or porous rocks are not suitable for expansion bolt! These include sandstone, marl and usually also (very porous) conglomerate. Tuff can also be very porous.

The picture shows a climber on a granite slab, in keeping with the theme "Establishing a climbing route with bolts". He is wearing an orange helmet and T-shirt and stands out conspicuously against the dark rock. The picture illustrates what is probably the best type of rock, granite, for using expansion bolt.
Solid rock such as granite is the best prerequisite for setting up a climbing route with expansion bolt. Photo: Rainer Eder

Explosive effect expansion bolt

For a bolt to hold, it must be donned accordingly. In the process, the so-called “cone” pushes into the expansion links. This means that the axial force of “donning” is converted into radial force. In short.

The expansion links press laterally against the rock. This ensures that the bolt is held firmly in place.

On the other hand, this also has a considerable “blasting effect”. If you want to set up a climbing route with expansion bolt, you need to be aware of this!

This results in the principle of the tear-out cone for expansion bolt. It states the following. If a piece of rock tears out, the radius of the tear-out cone on the surface is 1.5 x the setting depth.

In other words: If a expansion bolt is 10 cm deep, there must not be a crack or another tear-out cone 15 cm around it.

Consequently, expansion bolt must always be 3 x the drilling depth apart at lower off climbing anchors or abseiling points. As a rule, this is a minimum distance of 30 cm!

Set up climbing route with expansion bolt torque

The torque for expansion bolt is a small but very important detail.

This is because it describes the force with which a expansion bolt should be donned. Too little and the bolt does not hold properly. Too much and the hook gets too much material pretension.

To put it better: tighten properly, but not too tight!

The rule of thumb is: If you hear the “crack-crack” (“breaking open the expansion links”) at donning, leave it alone!

You can find the exact torque on the packaging. It can also be found in the manufacturer’s data sheets.

The picture shows a pack of expansion bolt with the torque value marked on the label. If you want to set up a climbing route with expansion bolt, you need to know this value. The picture immediately illustrates where the crucial information is located on the packaging!

Influences on the components

A glue in bolt sits encased in injection mortar “firmly” in the drilling hole. In other words:

  • 1 Component
  • no movement
  • nothing can become “loose”
  • No water in the drilling hole
  • Forces are distributed relatively evenly in the event of a fall

However, this is completely different with the combination of expansion anchor and bracket.

  • 5 (!) components: expansion bolt- shank, expansion links, washer, nut, bolt hanger)
  • There are tiny movements with every fall
  • Mother can become loose
  • Water penetrates into the drilling hole
  • Strong forces on the lug and 1st third of the bolt
The image describes the components of a expansion bolt. The individual components such as the nut, washer, thread, expansion links and cone are described around the expansion bolt. It describes the most important component in line with the topic "Establishing a climbing route with bolts".

It is therefore hardly surprising that the following negative effects occur:

  • Lower overall service life
  • Loose nuts and “wobbly” lugs
  • bent tabs
  • Missing tabs

3mm or 4mm bolt hanger

Would you like to set up a climbing route with expansion bolt? Then you should definitely know about the different bolt hanger. As a rule, lugs made of 3mm and 4mm thick sheet steel are available.

Our recommendations are:

3mm tabs

On the one hand, ideal for routes with normal frequency and where there is little falling. On the other hand, perfect for alpine access due to its low weight.

4mm tabs

On the one hand, ideal for routes with a very high frequency and where there is a lot of falling. On the other hand, for all applications where strong forces are applied, e.g. slacklines, flying fox, ….

Galvanic corrosion

Unfortunately, many developers are not aware of this chemical principle. Do you want to establish a climbing route with bolts soon? Then please take this advice to heart. Avoid mixing galvanized steel and stainless steel components at all costs!
For example, zinc plated expansion bolt and stainless steel lug.

Because this inevitably leads to corrosion!

You can find all the details on this topic in our article on galvanic corrosion at expansion bolt.

The picture shows an example of galvanic corrosion with two adjacent mounts of the same expansion bolt. On the left is the zinc plated expansion bolt with the stainless steel lug fitted, on the right is just the expansion bolt with the lug removed. The corrosion on the shaft is extreme and very obvious.
Galvanic corrosion at expansion bolt. Graphic: bolting.eu

The expansion bolt standard

The EN 959 – UIAA 123 standard defines the specifications for fixed points in alpine sports. It is particularly relevant for climbing crag owners. I.e. bodies that operate “official” climbing areas.

The most important points (simplified) are

  • All fixed points made of corrosion-resistant stainless steel
  • 15kN axial and 20kN radial breaking load for substrate / component
  • Drill hole depth: a fixed point must hold regardless of this
  • Anchoring depth: 5 x the drilling diameter for bolts
  • Eyelet shape and thickness for the lugs: min. 3 mm and 0.2 mm edge radii, as well as accommodation of 2 fasteners

You can find all the details on this topic in our article“EN 959 – UIAA 123 expansion bolt standard“.

Setting up a climbing route with expansion bolt – the diameters

Surprisingly, a frequently asked question from our customers is: Which expansion hook diameter should I buy?

We therefore want to answer this question below.

Standard 10mm and A4 steel

The current standard for climbing routes is clearly 10mm expansion bolts made of A4 steel. If you want to establish a climbing route with bolts, this is the best choice! On the one hand, they have the necessary breaking load values. On the other hand, they also have the right corrosion class for a long service life

You want to establish a climbing route with bolts “privately”? Do you have super solid rock like granite? Then we recommend slightly cheaper “short” bolts around 70mm. Climbing garden owners should fall back on the standard length of around 90mm.

In solid rock, the inexpensive Fischer FBN II in A4 steel performs perfectly. In somewhat more porous rock, the Fischer FAZ II. If you want to choose an even higher corrosion class, you need the bolts made of Fixe PLX / Duplex steel.

So-called HCR expansion bolt have the highest steel quality.

You can find all the details about the different grades in our article“Steel grades at expansion bolt and glue in bolt“.

Set up climbing route with expansion bolt – 12mm?

12mm expansion bolts in climbing routes make no sense from our professional point of view. This is because, as previously mentioned. Even 10mm bolts achieve the necessary holding forces for climbing.

From a technical point of view, a static fall into a expansion bolt with a webbing sling is the worst-case scenario. In other words, fall factor 2, which is why you should consider using 12 mm bolts, especially on multi-pitch routes.

8mm expansion bolt

You want to set up a climbing route with expansion bolt and use 8mm bolts? This is no longer common!

However, some developers use this diameter in alpine or high alpine routes. The reasons are easily explained. Firstly, the low weight of the bolt and lanyard. Secondly, the low battery energy for the drilling hole. And thirdly, the cost.

Incidentally, we only recommend zinc-plated expansion bolt or lugs for temporary fixed points.

Establishing a climbing route with expansion bolt – the steps

In the following, we explain all the steps in their chronological order. We have simplified this somewhat. This makes the article clearer. If you would like more detailed information, read our lead article“Bolting a climbing route“.

Set up a climbing route with expansion bolt

  1. lower off set up


    Always try to set up lower off first.

    – switch the lower off-climbing anchor in series: The expansion bolt must be one above the other. The distance must also be at least 3x the drilling depth of the expansion bolt (tear-out cone!).
    – Chain without tension: The chain of the lower off should sag slightly.
    – Deflection carabiner: This should protrude at a right angle at the lower anchor point. If necessary, use a rapid link to achieve this. The perfect position for the carabiner is hanging freely in the air.
    – Abrasion of the climbing rope: Avoid abrasion of the rope at all costs when climbing lower off. Choose a smart position to avoid rope abrasion on an edge or scale near the belay!

    After installing the lower off, you can clean and boulder out the route.

  2. Cleaning and bouldering


    Take your time if you want to establish a climbing route with bolts.

    On the one hand, this includes proper cleaning. You can find the right wire brushes and hand brushes here.

    And on the other hand, bouldering out the route. The ideal route becomes clear. It simply follows the path of least resistance. In other words, the easiest line.

    The picture shows a climber cleaning a route. He is on a gray rock face, with a lake and a few trees in the background on the left.

  3. Set clip positions


    Finds the best clipping positions when bouldering out. I.e. stable positions in which the quickdraws should be clipped. Pay attention to safe and regular hook spacing.

    Properly setting up a climbing route with expansion bolt means:

    – Adjust the hook density to the level of difficulty: Easy routes usually have a higher hook density. Difficult routes, on the other hand, need fewer fixed points.

    – High hook density at the start: There are deliberately more hooks in the first 5-7 meters. This is to avoid ground falls.

    – Landings and ledges: The same rule applies here as for the entrances. Ensure increased hook density to prevent “hitting” in the event of a fall.

    Due to the clip positions, the exact position of the securing points is automatically narrowed down.

    The picture shows a climber in a top rope on a rock face. He wants to set up a climbing route with expansion bolt and is therefore trying out the best clip positions. The picture illustrates this important step.

  4. Marking the hook positions


    If you want to establish a climbing route with bolts, you have to work very cleanly. That’s why we recommend the “5 point check”.

    – 1. elbow check: Use your elbow to check whether even a small person can hook the hook.

    – 2nd quickdraw check: Check whether the carabiner on the side of the rock or on the side of the rope has a cross-loading. To do this, sloper both a short and a long quickdraw on the rock to clarify this.

    – 3. grip and step check: Am I blocking my grip or step with the clipped quickdraw? You should avoid this at all costs!

    – 4. rope course check: The hook should be in a straight line with the other hooks. An even curve in the course of the rope is also okay. When it comes to “Perfectly setting up a route with bolts”, the following applies: the course of the rope simply has to fit!

    – 5. hammer test: Use the rock hammer to tap the place where the hook should go. There should be no “hollow” sound. It may be necessary to attach an extension from the nearest solid rock surface. This way you can still clip in the desired place!

    You can mark the fixed position of the expansion bolt with a chalk dot.

    The picture shows a climber setting an expansion bolt. He is in the abseiling position on the wall and is drilling into the rock with his left hand. Green trees in the background on the right.

  5. Set up actual climbing routes with expansion bolt – Set hooks


    Mark the drilling depth on the drill bit with climbing tape first. The diameter must be the same as that of the expansion hook.

    It must be possible to sink the bolt completely! Consequently, the drilling depth must be slightly longer than the hook used.

    Drill the holes marked accordingly. Clean the drilling hole with a blow out pumb or a hole brush. Then hammer in the drill hook and tighten it.

    Note the following details:

    – correct torque
    – thread protrusion min. 3mm and max. 6mm
    – tab resting flat on the rock

    The picture shows a climber setting an expansion bolt. He is hanging from a slab of rock and drilling into the rock with a cordless hammer drill in the foreground.

  6. Final theses


    Once the route is finished for the first time, the following usually remains to be done:

    – clean again and, if necessary, prepare the base of the wall
    – test climb to see if everything fits
    – tighten loose bolt hanger again with feeling
    – if hook positions are not successful: if necessary, attach screw links with extensions to the hooks or drill around hooks
    – make an assessment suggestion
    – give the route a name
    – mark it locally if necessary

    The picture shows the inscription of a climbing route with the name

Legal framework

The framework conditions are quite different in the countries of the Alpine region. To list them here would go far beyond the scope of this article.

For Austria, the climbing area handbook published by the province of Tyrol provides a very good overview of the entire topic.

Bolting a climbing route with expansion bolt – practical tips

In the following, we at bolting.eu offer you some practical tips. They should help you to avoid typical mistakes and make your life as a developer easier 🙂

Haulbag

Do you want to bolt multi-pitch routes? Then we advise you to use a small haulbag.

On the one hand, you can use it to transport all drilling materials and carry them on the approach. And you can also take it into the wall.

Simply hang it in the belay loop with screwgate carabiner. It dangles comfortably between your legs when rappelling!

Connect tools!

Murphy’s law. Anything that can fall down will fall down sooner or later!

You should therefore tie up all the important tools. Cordalettes or various lines and leashes are suitable.

Reserve material

Always take enough spare material with you in your bolting haulbag!

Drills, batteries and a second wrench. So you don’t have to go back to the ground if a drill breaks, a battery fails or material falls down!

Material bag

We ourselves use the practical material bags or tool bags for single-rope routes or bolting in the climbing area.

This is where the pitons, lugs, glue or squeeze guns and spare materials go.

Bolting checklist

Below we offer you a bolting checklist as a pdf download. It lists everything you should have in the wall. So you can’t forget anything!

Bolting checklist