Bolting Position and Technical Guidelines

10mm Ring Hanger10mm Ring hanger

NZAC consulted with members and the wider climbing community in 2010 on a Bolting Position which covers both alpine and cragging environments. This Position has a philosophical and ethical focus, whereas our previous bolting policies have taken more of a technical focus (see below). 

For more information on rock climbing and code of conduct practices in New Zealand see this webpage: Rock Climbing

NZAC Bolting Technical Guidelines (Updated November 2005)
This policy is to set a standard for bolting practices and hardwear. Its aim is to ensure high levels of safety, user friendliness and minimizing the environmental impact of bolts at crags. By using the appropriate technology, time, energy and money will be saved long term through not having to re-bolt routes frequently. 



  • Only stainless steel is to be used for all parts of the bolt, attachments and anchor.
  • If there is a choice between stainless grades 304 and 316, then the latter has greater corrosion resistance.
  • All parts of the bolt and anchor should be rated to at least 2000kg.

Expansion bolts: For hard rock only. Shouldn’t be used in roofs.

  • Trubolts (PDF 328kb) are the correct type of expansion bolt. Dynabolts are not to be used as they have under-sized shaft diameter in relation to the overall bolt diameter; e.g. a 10mm bolt has only an 8mm shaft.
  • 10mm diameter minimum for most places and 12mm diameter minimum for sea crags or areas with higher corrosion environments.
    75mm long minimum.
  • The hole drilled for the expansion bolt must be over drilled by 15-20mm (for the eventual hammering in and hiding of the bolt after re-bolting in the future).
  • Initially the rock behind the hanger will be rough - over time this roughness will be worn off which means the hanger will become loose. At this stage the nut needs to be retightened, and the nut should be ‘Locktighted’ on to prevent additional loosening over time.
  • By using a ring-ended spanner for tightening (not an adjustable spanner) the correct tightness will be reached and there is no chance of damaging the nut.

Eye Bolt 10mm x 120mmEye Bolt 10mm x 120mmGlue-in bolts: For all rock and especially good in roofs.

  • 10mm diameter minimum and 12mm diameter minimum for sea crags or areas with higher corrosion environments.
  • 75mm long minimum for hard rock.
  • 100mm long minimum for soft rock.
  • The hole must be over-drilled in diameter by 2mm to ensure enough glue is used between the rock and bolt; e.g. 10mm bolt and 12mm hole. Recommended glue = C6 epoxy resin.
  • The hole must be cleaned immaculately as the strength of the bolt is proportional to how well the hole was cleaned. Thorough cleaning will ensure the glue bonds to the pores of rock rather than sticking to dust. Water is very effective in cleaning the hole, however it should then be allowed to dry before gluing.
  • The head of the eyebolt should be slightly set into the wall to minimize the chance of rotational forces breaking the glue bond. This is done by chipping or drilling in 2-3mm, above and below the hole thus allowing the eyebolt to sit-in slightly.


  • An anchor must comprise of two bolts with some hanger or attachment which one can abseil off and not damage the rope: e.g. ring bolts, mallions or hangers with rap rings.
  • The anchor bolts should be level with one another and between 20 and 25cm apart.
  • All equipment on the anchor must be stainless.


  •  Re-bolting - 12mm diameter minimum for all places.
  • Glue-in bolts are encouraged as they can be removed for re-bolting.
  • The new bolt hole needs to be at least 8cm away from the old bolt hole.
  • The old bolt should be removed if possible or hammered in if it’s an expansion bolt and the hole covered by some glue or a rock fragment.


  • Ensure that where you are placing a bolt is very solid and part of the main wall. Not part of a block system and not near or on lines of weakness, joins, lips or edges.
  • The bolt hole must be exactly 90 degrees to the rock wall.
  • The 1st bolt should be at a reasonable height, no less then 3 meters but never at a dangerous height. 
  • The distances between the bolts should be in keeping with the climbing. Often the spaces between bolts do increase near the top unless it is cruxy terrain. 
  • At no point after the 1st bolt should there be ground fall potential (even with rope out for clipping). This is critically important and unfortunately a problem with many routes.
  • Long run-outs are acceptable as long they are safe and clean falls.

Other points to consider

  • The height of the route; can it be climbed and abseiled on standard rope lengths?
  • Does the line wander and cause too much rope drag, complicating climbing and abseiling?
  • Are the bolts placed at logical clipping positions (able to be lead ground up) and suitable for the height of all climbers.
  • Does the carabiner or quickdraw sit well on the rock. An incorrect placement can cause extra rope drag and wear the carabiner/webbing/rope on falls or resting? 
  • By using rounded hangers or ring bolts on popular sport routes which get climbed/worked frequently will extend the life of carabiners.

The NZAC is committed to the use of bolts only where necessary, while aiming for minimal impact.

  •  Hire from National OfficeBolting Drill: Hire from Canterbury/Westland SectionDo not bolt questionable routes. Some are just too dirty, loose, contrived or insignificant to warrant bolting.
  • Do not bolt naturally protectable routes. This is absolutely unacceptable if the line has good or even adequate natural protection. If the route has virtually no gear and is thus deadly or dangerous, then the new-router has discretion to add bolts if necessary. 
  • Use bolts which will last a very long time before needing to be re-bolted.
  • If possible reuse the old bolt holes (only possible with glue-ins).
  • If bolting a route in highly visible place, paint the hanger and bolt to help disguise it.
  • Respect local flora and fauna (birds such as falcons and other animals)
  • The use of chalk and tick marks should be minimized to avoid tagging the crag and to leave visiting climbers with the joy of the on-sight.
DOC_CMS_National_Consistency_Fixed_Anchors.pdf133.19 KB