Why You Need Screw Extractors And How Rennsteig Stands Apart

It’s a horrible feeling. You have been working in the shop for hours, laboring over your work and all-of-a-sudden everything comes to a halt. Why? A fastener broke and you can’t get it out. You can try and dig it out somehow, but most of the time the best option is to use some form of extractor, or as many call it, an “easy out.”

Spiral Screw Extractor.jpg
Spiral Fluted Screw Extractor in Tap Wrench

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.

Rennsteig Tools was founded in 1959 and became a member of the Knipex group in 1991. Among their over 50 national and international patents is their creative design for screw extractors. Though they have their own version of a spiral extractor, it is their “Dual-Edged” version that sets them apart. Made of high-strength chrome vanadium steel, the tools are tapered like any other extractor, but are fluted and double-edged, meaning they can be used in both right and left-handed (clockwise and counter-clockwise) fasteners. The dual edge cutting heads give you eight points of contact (four each direction), ensuring a solid bite into the damaged fastener. Not only that, it has a hardened center punch for starting your drilling hole and a hexagonal shank so that it can be used with a typical wrench or socket, eliminating the need for a tap wrench.

Rennsteig Dual Edged Screw Extractors.jpg
Rennsteig Dual Edged Screw Extractors with Hexagonal Shank

Check out this great demonstration of these by Tyler King of Rennsteig. Got a broken screw or bolt you need extracting? Get the Rennsteig Screw Extractors at your home for the best German Tools, KC Tool.


37 thoughts on “Why You Need Screw Extractors And How Rennsteig Stands Apart

  1. I have had the worst luck with “EZ” outs! After breaking an extractor in a broken bolt, the last go round I just immediately got out the Dremel and a tap. I would have a lot more confidence in these though.

  2. I like the extended shaft, maybe for hard to reach that oh-shit bolts. Right and left handed is also a good idea

  3. Like that they can be used with standard wrenches and sockets allowing greater reach into recessed areas with extentions. I personally will not have need for it often but the ability to get a bite in both directions could be a blessing to some.

  4. I was just looking at these yesterday evening. Pretty unique. I like how they will remove bolts in clockwise and counterclockwise!

  5. Great article. I’ve never had good luck with easy outs. My father showed me the “old school” way. Drill hole into broken bolt/screw, get a star bit slightly larger than the hole, hammer in, extract, throw the whole thing out. It works great! Finally this concept has been purpose built into an extraction set. Looks awesome!

    • I have lost many hours to damaged fasteners. Quailty tools (wera hex plus 👍) helps keep things from going south in the first place but these look like a great back up plan. I work with Ti hardware which can be fragile. Can’t wait to try these!

  6. Ich möchte diese ausprobieren, seit ich an die traditionelle “EZ-out” gewöhnt bin. Ich habe viel Glück mit ihnen aber nur weil ich neugierig bin und du bist nie mit deutschen Werkzeugen getäuscht!

    I would like to try these since I’m used to the traditional EZ out.. I’m having good luck with them but just because I’m curious and you’re never deceived with German tools !!

  7. I am a Wind turbine technician. Learn the hard way about the needs of a good screw extractor set while working in large correctives in the middle of winter in Minnesota. Having one will save you from a lot of headaches and down time.

  8. I’ve used those cheap SpeedOut extractors before and they were nothing but a pain to use, these look like they would breeze through the task with a dual-edge.

  9. Pretty cool idea . Also pretty cool that you can use a socket or wrench. Looks like they would be more than a one time use tool as well

  10. I’ve used multiple extraction tools but this one looks top of the line and looks like it would work correctly not like all these other ones I’ve used. They’d look great in my tool box

  11. Looks like a nice set of extractors. I’ll probably have to add a set next time I order. Rennsteig makes quality tools, and I’m sure these are some of the finest made. Thanks for the article.

  12. Getting my name in for the raffle because there’s nothing I hate more than a stripped out screw! Good luck to everyone. ^^

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