ZT 0566

Technical Specifications for Zero Tolerance 0566

This review is for the Zero Tolerance 0566 ELMAX® version which I have carried EDC since it was released. From Zero Tolerance here are the tech specs.

  • Made in the USA
  • SpeedSafe® assisted opening system
  • Frame lock, lockbar stabilizer
  • Quad-mount (tip-up/tip-down; left/right hand), deep-carry clip
  • Steel: S35VN, stonewashed finish
  • Handle: Textured G-10 front, stainless steel back
  • Blade Length: 3.25 in. (8.25 cm)
  • Closed Length:  4.45 in. (11.3 cm)
  • Overall Length: 7.70 in. (19.6 cm)
  • Weight: 5.4 oz. (150.3 g)

Basic Design

The ZT 0566 as you can see this is not the lightest knife and has some heft to it. For me this is ok because in the hand it feels solid and ready for the job. I carry it in jeans mostly and have tried in dress slacks which is not optimal due to the weight. The length works fine in the pocket and the G-10 texture doesn’t affect pulling the knife out. I have it set up as tip up right-handed and it works well for a smooth from pocket to blade deployment transition. The Hinderer Design frame lock works really well and doesn’t ever feel like the blade could release. Jimping (notches on frame) helps to get a solid grip to release the lock and the jimping all around on this knife works really well for a solid non slip grip. No issues with the pocket clip for me. I have had other Kershaw knives with the SpeedSafe® assisted opening feature and it worked well. On the ZT 0566 I don’t feel it works as well. Mine doesn’t snap open like my Kershaw OSO sweet. With the blade open the SpeedSafe torsion bar rattles around. If purchasing another ZT knife would probably step up to something like the ZT 0562 with KVT ball-bearing opening system.


Zero Tolerance seems to have changed the blade steel to S35VN for the standard offering. I will not claim to be a metallurgist so I will not speak to the differences in steel. I am also not a professional knife sharpener but the ELMAX® steel after a few tries is not hard to sharpen and holds an edge as well as any knife I have owned. The length, size, and the design of the blade works well for anything I have ever tasked it with.

Customer Service

This is where Zero Tolerance which is part of KAI along with Kershaw shines. I got this knife because I had a Kershaw Breakout 7000 that had a lock design issue and didn’t know about it. When it became an issue on my knife I called customer service and they said they were no longer fixing or replacing. He told me that he could give me the original purchase price of that knife toward any knife from ZT or Kershaw. Hands down Great Service there. They also have a knife sharpening service that is free. You fill out a Warranty Form and pay shipping to them but it’s shipped back to you for free.

Conclusion for Zero Tolerance 0566

It does take up some room in your pocket and is on the heavier side which may be an issue for some people. The quality of this knife makes the size a non issue for me. It is a well-built knife that will last and for me that is important. After buying several knives of lower quality which added up to way more than the cost of this knife quality is a real benefit. The only negative I have with this knife is the SpeedSafe® opening which is personal preference. If you are looking for a knife that feels solid in your hand and is always ready for the task take a serious look at the Zero Tolerance 0566.

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