Screw clamps. Screw clamps are types which use a screw mechanism to adjust the jaws and clamp a workpiece in place. The types which are found in the screw clamp category include G clamps (also known as C clamps), F clamps, edging clamps, wooden hand screw clamps and rack clamps.
Dry drowning usually happens soon after exiting the water, but with secondary drowning, there can be a delay of up to 24 hours before the person shows signs of distress. Both can cause trouble breathing and, in worst-case scenarios, death.
A rare phenomenon known as secondary, or dry, drowning may occur hours after a child leaves the pool, as water inhaled while swimming causes lung irritation and trouble breathing. The rare, potentially fatal, condition happens when someone breathes in small amounts of water during play, or a struggle.