A hammer should always be used for knocking in nails. The steel of a hammer head is specially heat treated to make the striking face hard enough to stop being damaged when it strikes a nail but not so hard that it becomes brittle and liable to shatter.
There are many different kinds of hammer. Some are designed for particular purposes such as bricklaying, panel-beating, stonework and upholstery. The two most common general-purpose hammers are designed for woodworking.
The curved claw hammer is designed for general-purpose woodworking and carpentry. The most common size is 16oz though 20 and 24oz hammers are also available. (The weight refers to the weight of the head.) Its weight makes it a quick, though tiring, tool to use and it is particularly useful for driving in long nails. It also has a hardened claw which is invaluable for pulling out nails and pins. The handles of curved claw hammers may be ash, glass fibre, hickory or steel. Glass fibre and steel-handled hammers usually have rubber hand grips.
The cross-pein (Warrington or joiners) hammer was designed for joinery and cabinet making. Standard sizes are 4, 6, 10, 12, 14 and 16oz. The smallest size is sometimes called a pin or tack hammer. The hardened cross pein (the tapered wedge end) is for starting small pins and tacks and for finishing off nails in awkwardly shaped mouldings. For metal-working, an engineer's hammer has a lounded ball pein.
Staple guns :
For many jobs - particularly upholstery, fixing fibre ceiling tiles and securing underfelt - a staple gun will be more convenient than a hammer.
A staple gun fires hardened two-pronged staples into the work: these look a bit like the staples used to hold paper together but are larger and tougher. Special staples are available for particular jobs such as ceiling tiles and for securing panel clips for cladding.
Staple guns can be used in one hand and have cither a lever or, if electrically powered, a trigger. Other uses include picture framing, roof insulation, roller blinds, polythene sheeting and fencing. Special attachments are available for some of these jobs.