Legs have strong, effective locks to prevent folding while in use.

"It has a strong lock, and a grate on the window."

Both doors were solid, with strong locks and good bolts.

"Is there a cellar with a good strong lock?"

"This box, it has strong lock on it," the other boy said.

This city is also known for hand-made strong locks.

Gloved fingers produced a duplicate key and turned the strong lock.

The door was slightly opened; its strong lock was broken.

The double lock, though strong, was not formidable to The Shadow.

It had a strong lock, and that was enough for the sheriff.