The tapered edge allows it to fit snugly into a range of sizes of screw heads.
3 Vintage Blue Point Tools Wrenches HL112P Channel Locks S-1012 S-1618 Open End
VINTAGE BLUE-POINT TOOLS AIR RATCHET WRENCH 3/8" DRIVE (UNK MODEL) (k39)
VINTAGE BLUE POINT TOOLS JAPAN 3/8” AIR RATCHET WRENCH SNAP-ON
Vintage Blue-Point Tools Auto Body Hammer BF-611 USA
Vintage Blue Point Tools USA CG-1 Gear Puller Attachment New in Box NOS
Vintage Blue Point Tools FB361 Spark Plug Gapper Patent Pending - NICE