How do hammerhead designs vary for different jobs?

Hammerhead designs for hand tools vary significantly to suit specific tasks, with differences in weight, face shape, and the design of the peen (the end opposite the flat face).12

• Face Shape and Material: Hammers used for beating metal into sheets require heavy, compact heads with flat faces. Conversely, "soft" hammers made of wood, bone, or antler are used when striking chisels to prevent damage to the tool being struck.1
• Peen Variations: The peen is specialized for different functions. While a flat face is used for driving nails, other shapes serve distinct purposes:
  • Claw: Designed for extracting nails.12
  • Hemispherical, Round-edged, or Wedgelike: Used by metalworkers to stretch or bend metal, or by masons to chip and break stone or bricks.1
  • Chisel-like: Used in specialized tools, such as the filemaker’s hammer, to score metal blanks.1
• Weight and Control: Weights range from a few ounces for delicate work to 15 pounds for breaking stone. The handle length and head design are balanced to manage shock loads and reduce operator fatigue during repetitive tasks.21