Finger locks and hand jams are crack-climbing techniques sized to the crack. A finger lock slots and torques the fingers into a thin crack; a hand jam inserts the whole hand into a hand-width crack and expands it to lock. Hand jams are generally more secure and restful; finger locks are thinner and more strenuous.
| Aspect | Finger Lock | Hand Jam |
|---|---|---|
| Crack size | Finger-width | Hand-width |
| Method | Slot + torque fingers | Expand the whole hand |
| Security | Precise, strenuous | Very secure, restful |
| Comfort | Hard on fingers | Scrapes hands (use tape) |
| Key skill | Torquing | Cupping & thumb |
Finger-lock when…
- The crack is too thin for a hand
- You can slot fingers and torque
- It's a finger crack
Hand-jam when…
- The crack is hand-width
- You can insert and expand the hand
- You want a secure, restful jam
Verdict
Frequently asked questions
What's the difference between a finger lock and a hand jam?
A finger lock is for finger-width cracks and works by slotting and torquing the fingers; a hand jam is for hand-width cracks and works by inserting and expanding the whole hand. Hand cracks generally feel more secure and restful.
What size is a hand crack?
Roughly the width of a hand, where a hand jam fits and locks comfortably — the most secure and restful crack size. Narrower cracks need finger locks; wider ones need fist jams or offwidth technique.
Does crack jamming hurt?
It can scrape and bruise the hands, especially while learning, which is why many climbers wear tape gloves. Finger locks can also stress the finger tendons. Done well, jams are secure, but the skin takes time to toughen.
Related: Finger Lock · Hand Jam · Jamming · Crack climbing