Why You Need Screw Extractors And How Rennsteig Stands Apart
I’m going to be honest and tell you that when I set out to write this post, I was hoping to give a ton of historical perspective about who invented the idea and when. I searched patents and documents to the best of my meager ability and couldn’t find a thing! Even the Wikipedia page doesn’t clue us in too much. The earliest info I can find is a 1914 patent for an “EZY-out” screw extractor made by the Cleveland Twist Drill Company. This is the only place I have seen the name spelled with a Y (EZY) and most modern spellings either leave the letter Y out or spell out the full word (easy). So, I am suspect to the true origins of the original design. The Cleveland Twist Drill Company merged with Acme in the sixties and are now produced through Greenfield Industries. I went so far as to contact Greenfield to see if they had any information, but to no avail.
What I can inform you about is the use and design of such a tool and how one of our German favorites has a unique variation on the original. All extractors use basically the same principle. A hole is drilled down through the broken fastener, the extractor is hammered into the hole and twisted in the proper direction to bite the fastener and remove it. This is typically done with a tap wrench since the shank of the extractor is square shaped. The most common extractor is of the “Spiral Fluted” design and looks like a cross between a drill bit and a screw thread, and in many ways, that is exactly what it is. The threading is backwards to the screws thread so as to dig into the fastener and extract it back the way in which it came.