Go Thin To Win? Okay...

tryppyr

tryppyr

Joined
Feb 5, 2010
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So often I have heard folks express the sentiment "Go thin to win." I have obviously taken the message to heart, especially after the two slicers I just made.

Only this time I may have taken it too far.

I started with CPM S30V bar stock that is 1 inch wide, 0.145 inch thick. The blade is a derivation of one of the Global knives my wife loves so much. The Global knife has a distal taper on the blade (0.09 at the plunge down to 0.02 at the tip) and an integral handle that is about 0.3 inches at the widest spot.

Mind you, I did not set out to make a clone, just something of similar size with superior sharpness. So the first thing I did was grind in a similar distal taper, then I set to doing the primary bevel grind.

Long story short, my blade is now significantly thinner than the Global it is modeled after. At the plunge it is 0.06, and it tapers down to 0.015 at the tip. At the edge it is 0.015. Worse still, I am not done with the pre-HT hand sanding. I'm not terribly concerned about most of the blade, but I am a bit concerned about the tip.

Do you think I'm likely to have a problem during HT?

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I think you will have problems but I am not sure if you will with cpm s30v. if you have aluminum quench plate you can try sticking them in a vice and whille the blade is still hot after you quench it stick it in between the plates and let cool straight (I am not sure if this will work on Stainless or not). anyway just my .02.
 
The tip will be very thin when done. You will have top be gentle with it. Don't pry any stuck drawers open with it, that is for sure.

If the tip gets too thin after hand sanding, just file it back a 1/4" and shorten the blade a tad. It probably would end up shortening itself sooner of later....best you decide what shape it will be in !
 
Is there a way to plate quench with 2 sets of plates so both the handle and blade have positive contact. I'm ready to order plates and tackle SS and I'm still miffed about how you can get an even plate quench when the surface is UN-even. Would S30V be to tough to grind post HT?
 
Nothing to add really but I would knock the tip back some working from the spine then hand file on the edge to make it a little beefier. From my limited experience .015 is near ideal. A lot of times I go thinner than that but I'm lightly convexing the edge from there and then hand sharpening.

No experience with S30V though.
 
I can't say whether plate quench is an option or not, since all my HT is done by Peters HT.

Anyway, I'll go ahead and shorten the blade, then finish hand sanding.
 
You can send it for HT , then if Peters cannot straighten it or if it gets the bacon edge , shorten the blade then (removing the wavy edge). .015 should be enough, as long as your grinds are pretty symmetrical you should be ok. This is the understanding I get from talking to Brad at peters. The blades I have done that thin came out fine in stainless, not so fine in 1095.
 
There is much hand-wringing and gnashing of teeth about this topic. I notice most of it comes from folks who are just repeating what they've heard from the "conventional wisdom". If you're really, really concerned about it, just have your blades HT'ed as blanks and grind them hard... like most factories do.

Thin is in and light is right. I am absolutely convinced that this holds true even for heavy duty knives, and without question for precision knives. The excellent steels and HT protocols we're blessed with today offer plenty of strength and toughness. Clearly, you're making a slicing knife that will be used with care, not a combat/survival knife like this:

[video=youtube;6f4HkkUikVU]http://www.youtube.com/watch?v=6f4HkkUikVU[/video]



tryppyr said:
Do you think I'm likely to have a problem during HT?
Click to expand...

That depends mostly on who does the HT. I send as-thin or thinner blades/edges than that to Peters' on a regular basis. The only (very minor) warpage I've gotten back from them was on a couple O1 blades. Even then, it was so minor that I was able to make it disappear with hand-sanding and sharpening.

If you are really concerned about the edge being too thin, just make a pass against it with a fine belt or stone. That will quickly get you back to a thickness of 8 or 10 thousandths.
 
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Thanks, James. You are correct... my wife does not use these knives for anything more challenging than slicing vegetables. :)
 
I have been pressing forward with this project as something of a stress reliever between bouts with the chef knife. My main objective this weekend was to get the blade ready for HT. That meant getting the blade sanded to 400 grit and getting the tang flattened. The tang needed flattening because it unsettled by the descaling process. All attempts to flatten it with sanders failed, so I decided to use the captive file approach.

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After about an hour or so I think I have reached a point of diminishing returns, so I'm stopping for now. I still only have the blade sanded to 180 grit, but that's what tomorrow is for.

I decided to use one of the Kirinite slabs for the handle. I showed my wife and she exclaimed, "Awesome!" I guess that means it was a good enough choice.

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I like it. The cant of the handle and the slightly raised tip/edge will help give you some clearance on a cutting board.
 
Just have a look at this guys slicer.

[video]http://www.youtube.com/results?search_query=India%20sandwich&sm=3[/video]
 
Part of the pre-HT prep is to make sure you have a workable handle solution, so I cut the Kirinite slab into two parts, shaved about a third of the material off the back, and drilled and countersunk the holes. Having learned the lesson from the Corby bolts, this time I made sure all of the Loveless bolts went smoothly into the countersunk hole deep enough to form a clean bond even after I sand down the surface.

I showed my wife and she said "How, looks kinda like Bakelite." High praise coming from some who collects Bakelite jewelry.

So now I think after I finish hand sanding the blade to 400 grit I'll finally be ready to send it off.

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