The square head allows the extractor to be fastened into certain tools. Tools such as a “T” handle wrench, bar type wrench, adjustable wrench or vice grip pliers can connect to a square head.
Spiral fluted extractor shaft
The shaft is made of carbon steel and connects the head to the flute.
Spiral fluted extractor flutes
The flutes are designed to screw anti-clockwise into the screw or bolt. While turning the extractor anti-clockwise, the tapered flutes dig into the damaged screw causing it to loosen and finally be removed.