Use a hammer only if it is in good condition. The head should not be mushroomed and it should be firmly attached to the handle.
Be certain that both the hammer and your hands are clean.
Hammers with damaged heads or broken handles should be repaired or replaced.
When replacing a wooden handle, apply glue to the wedge before you drive it into the handle.
Grip a hammer close to the end in order to make the tool weight work for you. Choking it is awkward and increases the chances for a smashed finger. Choking the handle also makes for a less effective blow.
Always wear safety glasses or goggles while using a hammer. This includes driving nails. A flying nail or other flying material can cause the loss of an eye.
Always keep your mind on your work, or you are apt to hit your fingers. Start driving nails by holding them near the head and hitting the nail with a light blow. This will minimize the possibility of flying nails and finger injuries. Use a flat-faced hammer to drive nails, never a machinist’s hammer.
Hammer handles are meant for gripping only. Don’t tap objects with them or use them as pry bars.
Don’t use a wrench, rod, or bolt or other piece of equipment for a hammer.
Never strike hardened objects such as a wrench or another hammer with a hammer or wrench. Use a rawhide, wood, rubber (weighted plastic hammer), or soft metal hammer.
Be sure you have an unobstructed swing when using a hammer. Watch out particularly for overhead obstructions.
Have a helper use tongs or other proper holding device when holding work to be hit with a sledgehammer. The helper should be positioned to the side of the person swinging the hammer, never in front. Be sure no one is standing within the range of your swing when using a sledgehammer. Both the helper and the person handling the sledgehammer should wear goggles. Other personnel should be clear of the area in case metal chips or other mater flies off when the sledgehammer is used.
There is a proper type of hammer for every hammering job. ALWAYS SELECT THE RIGHT ONE. Never use a derrick pin, pump shaft or other makeshift tool, in place of a hammer.