Key takeaways
- A bolt is permanent protection drilled into the rock, with a hanger to clip quickdraws.
- Bolts make sport climbing possible with reliable, pre-placed protection, and build fixed anchors.
- Types include mechanical expansion bolts and stronger glue-in bolts.
- Bolts age and corrode — assess their condition and don't trust visibly old, loose, or rusty ones.
What a bolt is
A bolt is a permanent piece of protection installed by drilling a hole into the rock and fixing a metal bolt with a hanger. Climbers clip quickdraws to the hanger and run the rope through them. Bolts provide reliable, pre-placed protection that makes sport climbing possible, and they’re also used to build permanent anchors.
Types of bolt
- Mechanical (expansion) bolts — expand to grip the drilled hole.
- Glue-in bolts — epoxied into the rock; generally strongest and most durable, especially in soft rock.
Stainless steel resists corrosion; quality and longevity depend on type, materials, and installation.
Bolt safety
Because bolts are permanent and weather over time, assessing their condition matters. A sound bolt is solid (not spinning or loose), free of significant rust, with an intact, unbent hanger.
Clipping up a sport route, a climber notices one bolt is rusty and spins in its hole — a warning sign. They clip it but don’t trust it fully, and at the anchor they make sure at least two sound bolts back each other up rather than relying on a single questionable one.
Old, rusty, loose, or homemade-looking bolts deserve suspicion, especially near the coast where corrosion is severe. Bolts are the modern, permanent successor to the hammered-in piton.
The bottom line
A bolt is the permanent, drilled-in protection that makes sport climbing possible — clip a quickdraw to its hanger and climb. Reliable when sound, but bolts age and corrode, so assessing their condition (solid, rust-free, intact hanger) is a real safety skill. Trust good bolts, be wary of old or loose ones, and never bet everything on a single questionable bolt.
Frequently asked questions
What is a bolt in climbing?
A bolt is a permanent piece of protection installed by drilling a hole into the rock and fixing a metal bolt with a hanger. Climbers clip quickdraws to the hanger and run the rope through them. Bolts provide reliable, pre-placed protection that makes sport climbing possible, and are also used to build permanent anchors at the top of routes.
What are the types of climbing bolt?
The two main types are mechanical expansion bolts (which expand to grip the drilled hole) and glue-in bolts (epoxied into the rock, generally the strongest and most durable, especially in soft rock). Both have a hanger for clipping. Quality and longevity vary with the bolt type, materials (stainless steel resists corrosion), and installation.
How do you know if a bolt is safe?
Inspect it: a sound bolt is solid in the rock (not spinning or loose), free of significant rust or corrosion, with an intact, unbent hanger. Old, rusty, loose, spinning, or homemade-looking bolts should be treated with suspicion, especially in coastal or harsh environments where corrosion is severe. When in doubt, back it up or avoid relying on a single questionable bolt.
Sources
- Bolting & fixed protection — American Alpine Club
- Anchors & bolts — UIAA