Broadhead: Used primarily for big game hunting. The number of steel blades it contains may vary. The only arrowhead that may be used for big game hunting is the broadhead. It must be solidly built and always razor-sharp. Many states have laws governing the minimum diameter and number of cutting edges of the broadhead used to hunt big game.
Mechanical (Expandable) Blade Broadhead: Blades are retracted close to the ferrule before the shot. Upon impact, the blades expand to expose the cutting edges. These are recommended for use only with bows rated 50 pounds or more because most require additional energy to open upon penetration.