About Bolt Products Bolt Products Homepage Bolting Information Catalogue
Sustainable Bolting and Bolt Removal

  Bolt Selection

Your choice of bolt will be influenced by many factors;- cost, anticipated traffic, route length, installation difficulties and rock quality to list a few.

The following information is intended to help you decide which of our bolts is most suitable for your application.

Strength and Tests
Bolt Selection
Orders, Delivery and Discounts
Protection Bolts

Belay Bolt

Sea Water Series
Single Point Lower-offs
Chain Extenders
Chain Sets
Stainless Steel Pitons
Maillons, Rings and Chain
Via Ferrata Equipment
Glue and glue guns
Service and support
Terms and conditions



Glue-in or Bolt-in?

For strength, durability and vandal resistance glue-ins are far better and are unbeatable on price so unless you need bolt-ins for the convenient installation these are the first choice.

Protection Bolts.
All our bolts are stronger than any other piece of equipment in the safety chain, the smallest diameter we use gives a minimum bolt strength of ca. 40kN!
The smaller the rod the lower the visual impact.
The smaller the rod the smaller the hole required.
The larger the rod the more robust and durable the bolt will be.

For 99% of routes our standard 6mm bolt will be the best choice, the 12mm hole reduces drilling time and allows economical glue use. The bolt itself has a low visual impact and is twice as strong as anything you will clip into it. Our 8mm rod bolts are primarily intended for use at belays and to replace old bolts which have been removed leaving a larger hole.

Belays and Lower-offs.

6mm rod bolts are suitable for belays and lowering-off but for repeated top-roping directly threaded through will give problems with bolt wear.
8mm rod bolts are much better but have durability issues in areas of very high top-roping use, often with a life of under 10 years.

While climbers should always top-rope through their own equipment experience shows this is generally not done. If the route is likely to be popular then an anchor with higher wear resistance should be chosen, maillons fitted or better still a dedicated lower-off.

Bolt Length
The shortest bolt we produce is 80mm long, this allows the use of inexpensive polyester glues. The unique design of Bolt Products rock anchors ensures that the bolt/glue interface will not fail, the glue/rock interface and the rock strength are the deciding factors.

Unless you are bolting in some very strange rock our stock 80mm long bolts are more than adequate as our test results show, if you want higher pull-out strength then note that for a given amount of rock removed by drilling a higher pull-out resistance is achieved by drilling deeper with a smaller diameter rather than going to a larger diameter.
Pull-out resistance is usually related to the glue strength and the rocks compressive strength, we stock three different lengths of bolts to cater for the most common applications.We have tested bolts in rock with a compressive strength below 10N/mm² (1400psi) which is on the lower limit of climbability and still achieved the required pull out resistance, (this rock is 20% of the strength of the standard test block for EN959 (50N/mm2)).
For rock with a compressive strength of 50N/mm² and over use a 80mm bolt.
For rock with a compressive strength of 25- 50N/mm² use a 100mm bolt.
For rock with a compressive strength of less than 25N/mm² use a 150mm bolt.

For a list of common rock strengths and how to calculate bolt strengths visit our Bolting Information pages.