Technical Notice & Instructions

Thank you for your purchasing Holds & Volumes from Serious Climbing. Please read the following instructions carefully and make sure you fully understand them before using our products.

All of the climbing holds featured on this website (Holds from Serious Climbing) are intended for use on wood and concrete surfaces and conform to the European norm EN 12572-3.

Guidelines for understanding Hold Sizes used in this notice

Please note that the definition of Climbing Holds Sizes vary largely from one manufacturer to another. We are therefore using the following guidelines for ease of use and reading.

  • Small holds:
    • Screw-ons, footholds, mini jugs, small crimps, etc.
    • Usually has only one bolt hole.
  • Medium holds:
    • Up to the size of an adult hand,
    • Longest side up to 15cm (approx.)
    • Usually has 1 bolt hole + 1 or more screw holes
  • Large holds:
    • Up to size of a rugby ball,
    • Longest side up to 30cm (approx)
    • Usually has 1 bolt hole + 1 or more screw holes
  • Features and Very large holds:
    • A mini-volume, made of either PU or PE
    • Size of a rugby ball and above
    • Longest side from 30cm and above
    • Usually has 1 bolt hole + a minimum of 2 screw holes


  • A minimum of 3 screw-holes and no bolt hole
  • Volumes
    • Made of wood or fibreglass
    • Does not have a bolt hole, but many screw holes instead

PE Holds – Safety System

All of the Polyester holds (PE) –from size MEDIUM – featuring on this website are fitted with a safety system inside.

The system is designed so that in the event of a hold breaking whilst being fitted or climbed on, both parts of the holds will remain attached to the bolt. Only very small pieces may fall down, thus reducing the hazard to users.

PU Holds – Safety

Polyurethane (PU) holds are not fitted with a specific safety system inside. This is because PU is a flexible material, making it a virtually unbreakable material. Holds are designed not to break in the first place.

Installation and Removal of the holds

Fitting and removal of climbing holds should always be carried out by experienced and qualified people, using appropriate fixings (specified bolts and wood screws) and fitting equipment (allen keys, drills). All of the climbing holds should be checked and cleaned regularly, and should only be used only on flat and even surfaces, which are clean and dry.

When fitted on the wall, holds should be checked regularly within the first few weeks of installation, and then a minimum of every 3 months. Be especially careful if the climbing centre is subject to large temperature changes, as dilatation of the climbing walls may result in premature and frequent loosening of the holds.

Holds should be removed from the wall at least once a year, and carefully inspected, especially around the bolt and screw holes. If any damage is found or suspected, please dispose of the hold or volume imeediately.


Always use common sense and due diligence when route-setting and installing climbing holds. If you are unable to use pinning screws, always carry out a risk-assessment, and determine the implications of a hold spinning. Take the necessary actions to minimize or remove the hazard.

When setting a Lead Route, always make sure that the holds will not interfere with the rope, and will not lead to the rope running directly onto a hold – especially when the climber will be lowered off. This would lead to premature ageing of the rope, and may create a groove in the hold.

Please also pay attention that large holds, features and volumes do not represent a hazard for climbers, in the event that a climber may fall off above the hold / feature / volume, and hit it.

Please be also mindful of setting moves that may be overly dangerous for climbers and/or spectators.

Bolts, Screws and Equipment

All holds presenting a 12mm bolt hole are designed to be used with either a countersunk or cap head bolt. Some thin bolt-on footholds may be better used with Button Head bolts, so the head of the bolt does not stick out.

We recommend using fully-threaded M5 wood screws for all places where a wood screw is required: pinning / wood screw holes on holds, and for fixing fibreglass and wooden volumes to the walls. Please ensure that a minimum of 10 mm is protruding from the back of the plywood.

PU Holds – adding wood screw placements

Feel free to drill as many wood screw placements to PU holds as you wish! PU is a very soft material, and if you are finding that some of the holds would benefit from an extra screw or two, just drill straight into the hold. Just make sure you are drilling no closer than 20mm from the edge of the hold.

Type of holds, and how to install them

You will find that most holds (except screw-ons and footholds) have both a 12mm bolt hole, and 1 or more additional 6mm screw holes. The main bolt hole is designed to take either cap-head or countersunk M10 bolts. Some thin bolt-on footholds may be better used with Button Head bolts, so the head of the bolt does not stick out.

IMPORTANT: The 6mm diameter hole is for placing an additional pinning screw, to prevent spinning of the hold on wooden panels.

Spinning holds are a hazard to climbers, please take all necessary actions to prevent it.

Here’s a general rule on how to fix de holds on plywood panels, depending on their size and shape, and the number of screw holes they present:

Type of Hold

Bolt & Screw Holes

Hold Shape or Size

Fixing method


Bolt-on Foothold, (Small holds)

1 main bolt hole


Single bolt.

You may choose to use a Button head bolt for thinner bolt-on footholds, so the head of the bolt does not stick out.

Standard Fixing Holds


(Most Medium to Large Holds)

1 main bolt hole, 1 screw hole

Medium-sized and above, up to Feature size

1 Bolt, 1 Wood Screw

Always apply the wood screw. This pinning screw is designed to prevent the hold from rotating or lifting off the wall.



(Usually small to Medium holds)

2 or more screw holes. No bolt hole.

Very thin holds

Place wood-screw in every screw hole

Do not overtighten, as such thin holds break easily.

Features, Very Large Holds


(a.k.a. Giga holds, Mini Volumes, BIG holds)

Lots of screw holes, either central in the case of tufas, or around the edges.


Possibly a central bolt hole.

Large or odd-shaped climbing hold. A mini volume that is not made of wood or fibreglass.

Always make use of all fittings provided.


As a rule of thumb, any hold found under the BIG filter of the website, or, any hold bigger than a rugby ball, should be placed using all fittings provided.

If there is one, the main bolt hole is never optional. Always place a bolt, as well as wood screws.

SPECIAL CASE: Dual Fixing Option (Standard or Screw-On)

Dual fixing option:


Standard fixing

or Screw-on fixing


(Usually Medium to Large Holds)


WARNING: Any hold that is: extremely positive (jugs), on which people can hang one-handed, OR that is very big (larger than a rugby ball),

and which present dual fixing options should be treated as a Feature (see row below), and the main bolt should not be omitted.

2 or more screw holes. 1 bolt hole.


Some holds have been designed so you could choose to either fit them the standard way (1 bolt + 1 pinning wood screw) OR to fit them using several wood screws.

Medium. NO JUGS or large catching hold.

Standard fitting: Main bolt + 1 or 2 pinning screws


Screws-only fitting:

Use all screw holes provided.

For long shapes, use one pinning screw on each end of the hold.


For offset shapes, choose the screw-hole that is the furthest from the bolt.


For round-ish shapes, choose the screw hole that is going to most prevent the hold to rotate or lifting off the wall.

Suitable climbing wall surfaces

All holds and volumes should be used on flat surfaces that are clean (free from grease and debris) and dry. Uneven surfaces may result in the holds spinning due to under-tightening, breaking due to over-tightening, or loosening too fast.

Please be aware that different surface and textures will require different torque settings to prevent the holds from spinning.

We recommend that holds are fitted on Plywood that is 18mm minimum. Holds installed on textured plywood (sand-coated or friction paint coated) will require less torque, as the texture will give a better adherence to the holds, and will participate in preventing the holds from spinning.

Smooth and Glossy-painted plywood will require to use more torque when tightening the holds, as the holds will not grip as much as they would on textured plywood, and will tend to spin more.

Holds may also be installed on GRP and concrete walls. However, please be extra careful with setting on such surfaces, as you might not be able to fit the holds with the required anti-spin wood screw. This means assessing the holds and their placement on a case by case basis to evaluate their risk of spinning, and checking the tightening of the holds even more regularly, to ensure none of them are loosening.

Finding the appropriate torque level

Different manufacturers recommend different torque settings, according to how they define hold sizes, and depending on the climbing wall surface. Glossy / painted walls will require more torque, whilst sand-textured walls require a lot less.

Please also check the tightening of the holds regularly, as it is very common for the holds to loosen over time: check regularly, and tighten if needed.


Please ensure sufficient torque to prevent rotational movement of the holds.

However, please do not overtighten, as too much torque could result in the hold breaking, or in damage to fixing points (T-Nuts, anchors) in the climbing wall.

The following recommendations are based on the counter screw / pinning screw being used. For other supports, where it is not possible to use a pinning screw, please increase the torque by 5 Nm.

For textured / sand-coated / friction-painted walls, we recommend the following torque settings

  • 15 Nm for small holds (footholds)
  • 25 Nm for medium holds (approx size of an adult hand, longest side up to 15cm)
  • 30 Nm for large holds (up to size of a rugby ball, longest side up to 30cm)
  • 40 Nm for very large holds (size of a rugby ball and above – 30cm and above)

For untreated plywood walls, we recommend the following settings

  • 30 Nm for small holds (footholds)
  • 35 Nm for medium holds (approx size of an adult hand, longest side up to 15cm)
  • 40 Nm for large holds (up to size of a rugby ball, longest side up to 30cm)
  • 45 Nm for very large holds (size of a rugby ball and above – 30cm and above)


Please do not shock-load the holds.

Please avoid using existing holes in the plywood as fixing points for your woodscrews.

Impact drills are generally not recommended by climbing hold manufacturers, as improper use may result in breakage of the holds. Please be extremely careful if you do decide to use them. Impact drills may damage the holds and create weak spots, lines and cracks within a hold, and could lead to the hold breaking when climbed on later on.

Installation of Volumes – Wood and Fibreglass

Please affix volumes using all screw placements.

Please use fully-threaded M5 wood screws. The screws should be long enough so that they protrude at the back of the plywood wall, by a minimum of 10mm.

Wood screw holes are generally placed every 200mm. For wooden volumes, wood screw placements should be no less than 2 per side.

If this is not the case, it might mean that a hole placement was forgotten during manufacturing.

If in doubt, please check with us, or discuss with a professional, to assess whether the volume is safe to be put on the wall with the number of screw placements, or if it is a manufacturing defect.

Resolving the issue / removing the doubt, is often as simple as drilling an extra hole or two to the side of the volume (drill at 4mm for a M5 wood screw) for additional wood screw placements. Never hesitate to add more screws if in doubt that there are enough for the use you want to make of the volume!

Bolts & Screws

Bolts and Screws are not are not included with the climbing holds.

All of the holds on this website feature a Dual Fixing bolt, and can take both countersunk and cap head bolts.

For smaller footholds presenting a bolt hold, you way wish to use Button Head bolts, so the head is flatter and does not stick out.

Screw-on holds, which present 2 or more wood-screw holes should be placed using as many wood screws, as there are holes.

Cleaning & Maintenance

Climbing holds should be cleaned regularly, depending on the amount of traffic they receive, as magnesium and rubber builds up and reduces friction. We recommend the use of a pressure washer at a temperatures of 30°C maximum. Alternatively, clean under clear water and brush excess chalk and rubber with a hard, non-metallic brush.

Do not use any acid, acetone or any other chemical product as this may damage the surface of the hold, affect the color and/or the structure of the climbing hold.

Be careful when handling the holds, and avoid that the holds fall or bang into each other, as shocks may create structural breaking within a hold.

Please check regularly (visual assessment) for signs of breaking and cracking on a hold. If you spot as much as the beginning of a crack at the back of a hold, discard immediately.

In the event of a chip on the side of a hold, file or sand down the sharp edge with sand paper or a file.

Climbing holds should be stored in a dry & clean area.

Climbing on the holds

We recommend that climbers use clean climbing shoes to climb on the holds, so the surface texture of the hold does not get prematurely polished.

Disposal of holds and volumes

Damaged holds and volumes must be disposed off appropriately, in the appropriate waste container, and in accordance with your local environmental policy.

Damaged holds must not be kept in a place where they could be removed or reused. Please do not donate or hand down damaged holds to anyone.