Broken tip

A

Artilary6

Joined
Oct 2, 2007
Messages
132
I decided to see how the Green Beret dug into wood, so I gave a light stab into a plank of wood and tilted the knife to the side to tear out a small piece of wood. I heard a tiny "snap" sound and when I looked at the tip....it had snaped right off the end of the knife like a brittle piece of glass. Looking at the knife from the side, the horizontal length of the break line is about 1/32" long. Is this my fault for sharpening the knife too fine at the tip? I suspect it might be, but I didn't know you were supposed blunt the tip so it wouldn't break off. I gave a few more hard stabs out of frustrated curiosety and dug the wood out to the side again to see if it would break further, and it didn't as far as I can see. So...what to do? When I sharpened the knife I only went 17deg per side from the back of the blade all the way up to the tip. The bevel didn't look very thin or fragile at all. It looked like a solid grind, not too far from the original grind, except for the fact that the edge was shallow enough to be sharpened with the Sharpmaker along the whole length of the blade. So...does it sound like I just noobed it up? Or should the tip have been stronger than this.
 
well, the tip on a fixed blade is the weakest point, since it is normally the thinnest all around.

you thinned the edge? the chief complaint i have heard about s30v is its brittleness which makes it prone to chipping, though i have not experienced this.

the tip shouldnt be blunt, but there is a limit to how thin it should be and how acute the angle toward the tip should be.

you may have contributed to the tip breaking, but it is an easy fix. just reshape the tip with a file and resharpen.

or, you could give crk a call and see if they will make the repair for you.
 
A knife is not a pry bar. I'm sorry that happened to your knife. CRK will no doubt fix er up but will tell you what you should know already- no prying.
Lycosa
 
Maybe i've seen too many Knifetests.com videos? lol. The tip break is really pretty small and i'll carefully repair it using MORIMOTOM's suggestion. Of course I realize that repairing it myself is taking on the responsibility of doing it correctly. This should have easily been a common sense thing. A very sharp, fine tip being stabbed into wood and bent to the side might break it! Why didn't I know that? I will chalk this up as experience and move on. Thanks for the replies,
-Ryan
 
To be honest I'm not surprised that the tip busted off your GB. From what I've read S30V is very prone to chipping along the edge when making contact with hard objects. If you look at uncoated S30V there is a descernible vertical grain, that looks suspiciously weak IMO. I think this steel is excellent for small folders where really hard use (prying, chopping, digging) is not typical. I have several S30V folders (mostly Spydercos) that slice like hell, but I would never use them to dig/pry etc unless absolutely necessary. That said I don't think this steel is a good choice for hard use fixed blades. A knife from CRK carrying the Green Beret moniker should be something you can beat on without worry. I had a CRK Sable IV in A2 and I chipped the edge quite badly when attempting to open a tin can with it. I had read many instances of the CRK one-piece line blades being used for tasks like this. To say the least I was extremely disappointed and subsequently sold the knife. I have moved on to another company who touts nuclear toughness and have had no chipping or breakage issues. CRK makes fine blades, but I was not impressed with the strength of the steels used. CRK will undoubtedly take care of you well. Contact them to see what they say. Good luck.
 
S30V and a hollow grind aren't well suited for prying ... no knife is. But if you're going to pry something, a good spring steel like 5160 and a convex/ flat grind is better than any stainless and a hollow.
 
I tried the same prying with my old KA-BAR (also has very sharp point from when I sharpened it) and it tore up the wood without taking any damage. I also have a dagger made of 440 stainless with a very sharp point. I did the same digging and no breakage. Only the "tough and uncompromising" Green Beret snapped. I still like the knife and won't sell it, but I also won't use it as a utility knife at all as it clearly can't stand up to the hard use. Why it can't, I don't know. But the proof is in the pudding.
 
But the proof is in the pudding.
Click to expand...

Heh, I get a kick out of statements like this. Have you tried resharpening and repeating? Have you tried sending it back and asking CRK? I'm not saying there's not a problem, I'm saying you don't have nearly enough evidence to come to that conclusion.
 
I have used knives for prying, even slipjoints, and I never break the tips. You see, I know the tip is the weakest point -- it's the thinnest, and the farthest from the handle. So when I pry a tight drawer or window with a knife, I insert the blade as far as it will go, and pry with the ricasso.

Amazing, materials and leverage used properly win every time.

S30V and the Green Beret specifically were developed and designed for exactly the kind of hard use a soldier would encounter in the field. Of course, if you're going to modify it, especially the tip, and then criticize the knife as being somehow lacking, you're missing the point. (I had to say that. The Devil Made Me Say That.)

Call CRK. Explain what happened. Or send them a link to this thread. They will offer to fix the tip and make it durable enough to stand up to picking wood with it if you like, or advise you how to do it yourself.
 
"...the horizontal length of the break line is about 1/32" long."
------------------------------------------------------------

It sounds like a very small part of the tip broke off.

I wonder if the change you made to the tip may have started a small fracture in the tip?
 
You might want to consider a Mission titanium knife. They are supposed to be very durable for what you have in mind. Or a Busse. When I pry, I use a pry-bar.
Lycosa
 
I didn't really know that sharpening the knife was considered modifying it. I tried using the sharpmaker to sharpen the knife in the first place, like CRK recommended, and it would not sharpen the belly because the edge angle was much more obtuse there. How are you supposed to use the sharpmaker on a knife that has an edge angle that changes along the knife's length? I made the angle constant along the length of the knife at 17deg per side. Then the tip snapped. If I was supposed to somehow rotate the knife as the belly met the rods in order to compensate for the dynamic angle on the knife, then thats my bad. Maybe I just need to learn how to sharpen properly. I'll keep reading up on it. If I can cope with the embarrasment, maybe i'll call CRK to ask for their opinion/advice.
 
You don't have to be embarrassed. As Rich357 said, it's a small break. If I'm visualizing it correctly, once sharpened over, it's the sort of thing that you won't even notice. After all, that sort of wear is inevitable over the life of a hard-use knife that gets sharpened for ordinary reasons.

Keep in mind that many people sharpen their knives at very acute angles to take advantage of good steels as slicers. Some people prefer massively thick and heavy blades for other uses. But torque on a slicing edge is dangerous, especially in something like wood where you may be twisting against a knot without knowing it.
 
So different edge geometry will clearly effect the durability of not only the edge, but the tip as well since the edge ends there. Bending it sideways while stuck in a board was stupid lol. Won't do it again as I have no need to. I only did it out of curiosity. I just saw so many knives pass that area of the "destruction test" on knifetests.com that I figured the Green Beret would surely hold up, and it probly would have with the original edge. I'm not usually a monkey see monkey do kind of person, but I couldn't resist. It was wrong of me to criticize the knife or its design. I'll get it sharpened over and back to a nice point again.
Thanks,
Ryan
 
As you noticed, the edge geometry originally thickened toward the point. Since there is naturally less material at the very tip, this thickened geometry is a way to strengthen it. It does take imagination to sharpen, just as a recurved edge does. That's a reason to investigate sharpening by hand, or with sandpaper to develop a convex edge.
 
OK so that was a little too easy. Using the flat side of the Sharpmaker brown rod as a file easily smoothed away the broken area. A few gentle strokes along the end of the belly by the broken tip created a nice, smooth transitioning tangent right back up to the spine to create a new, sharp tip. With a quick pass or 2 on the JET wheel, the edge will be restored near the tip and I can then resharpen on the Sharpmaker. It literally took about 2 minutes to smooth away the break area. Makes me feel like this whole thing was just a non issue. Thanks to MORIMOTOM for the fix technique and others for their advice & support. I think I just learned how to fix a broken tip =)
 
Artilary6 said:
I tried the same prying with my old KA-BAR (also has very sharp point from when I sharpened it) and it tore up the wood without taking any damage. I also have a dagger made of 440 stainless with a very sharp point. I did the same digging and no breakage. Only the "tough and uncompromising" Green Beret snapped. I still like the knife and won't sell it, but I also won't use it as a utility knife at all as it clearly can't stand up to the hard use. Why it can't, I don't know. But the proof is in the pudding.
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Ka-Bars are made from 1095 steel. Much tougher than S30V.

5160 is even tougher. I recently slugged a 1/4" thick 5160 knife (@ HRC 61 with a soft back draw) with a sledgehammer and couldn't break it, it eventually bent after 20+ hits -but wouldn't snap. Try doing that with S30V. I bet it'll snap on the first hit. Can you tell I'm an advocate of high carbon steel. :D

S30V isn't bad, it just isn't tough. Crucible advertises it as "tough" for a stainless, "approaching A2 toughness" -but in all honesty, I've tested it and it isn't as tough as A2... and A2 is no where as tough as 5160.
 
Also, s30v is made from powder metallurgy, so it should naturally be more prone to impact stress rather than being a soft metal. There is always a trade-off between brittleness and hardness. Just look at sapphire crystals - hard to scratch, easy to chip.

At least CRK has the best customer service in the biz to help you out...
 
The difference in metallurgical properties is pretty fascinating. For the most part, I find myself favoring the idea of a steel being good at edge retention and stain resistance rather than being super tough. Although, from what I've read the only quality that some high carbon steels lack is the stain resistance. Lets invent the BE ALL END ALL of blade materials! This is probly far fetched, but I believe theres a good chance that in the not to far future a nano material will be developed that will exceed at all desirable blade properties far beyond any steel. Having a super strong and well engineered micro-structure, a synthetic nano material would probly succeed at achieving "be all end all" status. Anyone agree?
 
Artilary6 said:
I find myself favoring the idea of a steel being good at edge retention and stain resistance rather than being super tough.
Click to expand...

This makes perfect sense for an EDC folder, whether tactical or slipjoint. It should also work fine for a hunting knife. Heavy choppers really need high carbon steel rather than stainless.

While I can understand the choice of stainless for some field knives, especially for mass market, non-knife enthusiast customers, knife knuts should be able to maintain high carbon blades in the field.
 
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