Heh, yeah, the thread has grown fast, there's three pages between this
Anyway, I don't know about Kershaw, but I know Benchmade and Spyderco both use .0005"
http://www.benchmade.com/about_knives/index.asp
I can't find the specifics of Spyderco's machining tolerances nor an official source, but this post ( also from Sal Glesser ) indicates that they grind their edges to .0005, but that doesn't necessarily mean they machine all their parts to those tolerances... I'd like to see some verifiable proof one way or the other
http://www.bladeforums.com/forums/showpost.php?p=8698384&postcount=229
I wouldn't be surprised if Kershaw and Spyderco machined their parts to .0005" along with Benchmade and CRK because .0005" is kind of the defacto machining tolerance when it comes to CNC stuff these days. I believe the only people playing with anything tighter are NASA or other aerospace researchers. Either way, you have right there from the source itself that BM is using the same tolerances as CRK.
I'm not a manufacturer, but I worked as a machinist for a few years, and I understand this quote very well. "That's one sixth the thickness of a hair. Do you have the knowledsge and equipment to discover that tolerance?"
Simply put, without several thousands of dollars invested in various pieces of measuring equipment, and the knowledge to use them properly, no one can possible appreciate let alone perceive the differences in tolerances---and from what I've just been able to dig up, there are no differences if Sebenzas also have .0005".
It's been a few years since I did that kind of work so I don't really remember all the tools, but between a surface plate ( usually granite in this circumstance so it doesn't corrode ), a vertical scale and an inch indicator, none of us are going to see a lick of difference in craftsmanship. Now, if someone were to spend the $10-15k to acquire this tools and started measuring their knives I'd start listening to the talk about "tolerances" but at the point we stand most people talking about them cannot even measure them, and aren't aware that the grand majority of manufacturer's using CNC machining have the same tight tolerances.
So aside from tolerances, as we've just put the proverbial nail in the coffin thanks to Sal's information on CRK's machining tolerances, let's talk about other areas of quality where the Sebenza outshines other manufacturer's.
I'd like to hear more about what's involved in the heat treatment of these knives. Perhaps that's where this fabled leap in quality lies?
Anyway, I just want to cut right through the hype. I'm not paying for a brand name? Okay, then... So what am I paying for?