Nothing Personal: KAI Explains Patent Action

After news broke that KAI, maker of Kershaw, Zero Tolerance, and Shun knives, had taken action against Microtech Knives in defence of its 2015 U.S. sub-framelock Patent, many questions remained unanswered. What exactly did the patent cover? What would retailers do with infringing merchandise? What was behind KAI’s decision? And who else would be affected?

To better understand KAI’s perspective, we spoke to Thomas Welk, Director of Sales and Marketing at Kai U.S.A. LTD.. The knife executive told us the last time the company went to the mat for one of their inventions, it was hardly a positive experience. “We had to protect the multiple patents associated with SpeedSafe – it was very expensive litigation, really unpleasant,” recalled Welk. “Nobody likes litigation, but if you invest in IP [Intellectual Property], you have to be ready to protect it,” he said.

Legal maneuvers in the knife industry are usually met with a public backlash. Some have speculated that this action is part of a feud between KAI and Microtech that traces all the way back to 2012 when Microtech released the Matrix, a knife that bore a striking resemblance to the Zero Tolerance 0777. The ZT0777 was one of the first sub-framelock knives made by KAI, but Welk said the recent move is not retaliation and just a coincidence: “Our decision to pursue this patent had nothing to do with any specific manufacturer.” According to Welk, KAI had identified an innovation worth investing in, and it’s all business. “We had positive feelings when developing this specific lock,” Welk said. “We put in the time, energy, and investment in hopes that it would be awarded a patent.”

The Patent for the sub-framelock was filed in early 2012 and granted in late 2015. It encompasses 20 claims, but according to KAI the mechanism it protects is still fairly specific. Despite its use of a detachable lock bar, an inset liner lock like the one found on the new CRKT Homefront won’t be affected. It also doesn’t apply to Todd Begg’s bolt-on lock, which is anchored by the knife’s backspacer. Knives will be evaluated on a case-by-case basis and KAI’s legal team will make the final decisions on what constitutes a Patent infringement in the company’s eyes.

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All indications are that Microtech and dealers will stop selling Microtech knives that use KAI’s sub-framelock by August 1st. We reached out to Microtech for confirmation, but the company declined to comment. Dealers we spoke to tell us that they’d rather not get between two of their partners but understand that in an innovation-driven environment like the knife industry, intellectual property disputes do arise from time to time.

Meanwhile, sales of Microtech Knives with sub-framelocks are accelerating as collectors look to corner what remains on the market. “These will be the last Microtech models and Marfione Customs with sub-framelocks that will ever be made,” Howard Korn, Founder and Owner of, said. “When popular knives stop being produced they become even more in-demand. They turn into collectibles.”

Knife featured in image: Kershaw Knockout