| Placed in | Solid ice |
| Function | Lead protection & anchors |
| Holding power | Depends on ice quality |
| Difficulty | Advanced |
An ice screw is a hollow, threaded tube that an ice climber twists into solid ice to create protection or build an anchor. Modern screws have a hanger and a fold-out crank for fast placement with one hand. Their holding power depends entirely on ice quality, so reading the ice is as important as the placement itself.
How it works
The threaded tube cuts into solid ice and the surrounding ice column provides strength. Used for ice climbing lead protection and anchors.
Ice quality is everything
The ice, not the screw, is usually the weak link — solid, cold ice holds far better than aerated or sun-baked ice. Choose the best ice and back up key placements.
Sizing
Carry a range: long screws for thick ice, stubbies for thin.
Frequently asked questions
How do ice screws work?
You start the threaded tube into solid ice and crank it in until the hanger sits flush. The threads and the column of ice inside and around the tube give it holding power. A well-placed screw in good ice is strong; a screw in poor, aerated, or sun-baked ice can be alarmingly weak.
How strong is an ice screw?
In solid, cold ice a modern screw can hold well over the forces of a typical fall, but strength varies enormously with ice quality, temperature, and placement angle. Because the ice — not the metal — is the weak link, climbers favour the best ice and back up critical placements.
What length ice screw should I use?
Longer screws (around 16–22 cm) are stronger and preferred when ice is thick enough; shorter 'stubbies' (around 10 cm) are for thin ice. Climbers carry a range and choose based on the ice depth at each placement.
Sources
- Ice protection technical notice — Petzl