While bolts are commonplace in rock and gym climbing there is no universal vocabulary to describe them. Generally, a bolt hanger or a fixed hanger is a combination of a fixed bolt and a specialized stainless steel hanger designed to accept a carabiner, whereas in certain regions a bolt runner or a carrot describes a hangerless bolt (where the climber must provide their own hanger bracket and sometimes lock nut). A ring bolt has a loop on one end so it presents as a U-shape embedded in the wall.
Bolts are subject to corrosion and stress and the combination tends to cause stress corrosion cracking. A bolt in an aggressive tropical climate such as Thailand can fail in as little as 18 months. In more temperate regions, a lifespan of 10–15 years is typical. There is a lack of effective standards and maintenance in many places but new materials such as titanium are now being used to improve the expected lifespan.
- Jeff Achey (23 April 2014), "Built to Last? The Hidden Dangers Of Climbing Bolts", Climbing