Mesed up my BRKT Grasso II

[bass806]

I'll mic it tonight, I'm at work right now. And yes, no metal or other debris located. Just a good ol piece of dead tree-and not all that thick either.

 

[Polamalu]

No need to air it out anywhere else- it is what it is. I'll send it back and report what they do for me. Thanks for the replies.

please do. lets see how they will re profile the edge. i suggest measure it blade height before sending it in so you can know how much metal they take out

 

[FortyTwoBlades]

bass806, before you send the knife in, can you take a micrometer to the blade and measure the thickness of the steel at the back of the dents as well as the distance from the apex to the back of the dent? Tell us if the damage is >1/16" deep and the edge is <0.015" thick.

FortyTwoBlades is correct that the edge is ground too thin, but the Grasso II is advertised as 5160 steel @ 57-58 Rc, and I have read that BRKT outsources the heat-treatment to Peter's in PA, a respected company. At 57-58Rc, 5160 steel at even 0.015" behind the edge should not take such extreme plastic deformation from chopping wood. My guess is that the metal behind the dents is plenty thick for the advertised hardness, but that the edge is NOT actually 57-58 Rc but is closer to 45-50 Rc, over-tempered, perhaps by machine-grinding. Either that or the damage did not occur as you indicated. YOu are certain that no nails/staples or bricks were involved?

Softer steel requires more material support to prevent deformation, harder steel requires less. Tough steel requires less material support to prevent fracture, brittle steel require more. 5160 @ 57-58 Rc is both hard and tough.


It's funny, the name of the knife always made me think, "Why would anyone want a bolo for cutting grass?" Apparently this knife may only be suited for such tasks...

Actually--now that you mention it I remember seeing mention somewhere that BRKT grinds all of their blanks POST heat treatment. With how thin they run their stuff that really does open the door wide to massive overheating of the edge region.

And yeah--Peters' does absolutely top notch work so I doubt it's their fault by any stretch.

 

[CSG]

If you like pocket saws, look into the Silky Pocketboy, Bahco Laplander, and Corona.

Why? I like and have used the Gerber for quite a few years with excellent success.

 

[CSG]

That's certainly a valid opinion, but hardly the matter at hand. The question is if bass's chopper should be able to chop, and what should be done if it cannot....as JollyRoger pointed out.

The main reason I responded to this was not so much to the OP but someone else wondering if a chopper is a good outdoor tool vs. considering a smaller bushcraft knife and something like the Gerber saw to process larger pieces of wood. Just based on many years of experience doing backcountry SAR.

 

[marcinek]

The main reason I responded to this was not so much to the OP but someone else wondering if a chopper is a good outdoor tool vs. considering a smaller bushcraft knife and something like the Gerber saw to process larger pieces of wood. Just based on many years of experience doing backcountry SAR.

I am not questioning your expertise, and I happen to agree with your opinion about the utility of folding saws. I'm just saying you are taking this thread away from its topic. That said, thread drift is quite common.

 

[bass806]

Ok, first off I didn't realize how difficult it would be to accurately measure the convex edge of the Grasso. The best I can come up with for the actual edge with my digital caliper is 0.013". That is the point that the caliper rests along the edge of the blade. The 0.013" measurement has bite on both sides of the edge(if that makes sense). This is consistent along the entire edge of the blade until reaching the handle area and then it thickens to about 0.014 to 0.015". Of course if you go further into the edge it increases.
The depth of the dents appears to be 0.011" into the blade and the blade thickness at the top of the dents is 0.025". Hope that makes sense.

 

[CSG]

I am not questioning your expertise, and I happen to agree with your opinion about the utility of folding saws. I'm just saying you are taking this thread away from its topic. That said, thread drift is quite common.

You mean like you reminding me that I'm off topic as you see it?

 

[RemyKaze]

Ah, looks like they redesigned it:

http://www.gerbergear.com/Outdoor/Gear/Sliding-Saw_22-41773

This and a proper bushcraft/survival knife like a Fallkniven F1 is a far better combo for outdoors activities IMO. Choppers make no sense to me other than the primal fun of trying to successfully use one (who wouldn't like whacking on stuff with a big ol' blade even if not a terribly efficient tool?).

Just a different perspective on outdoor tools, I guess.

Efficiency is based more on the user, really. What you find useful, I may not, and vice versa. I am more versatile with machetes and so choppers are more effective for me than an axe would be.

 

[Mikael W]

Quote Originally Posted by Grampa.

FWIW, Bark River heat treats its knives to be tough rather than brittle - so you do tend to get dings like this when hitting something harder - like the core of the small branch in your picture. Mike's idea is that it's better when out in the woods to have a bent ding than a chip missing, since you can still use the knife, and on small dings even realign it to some degree. Still, I agree that the edge seems to be ground a bit too fine and should be reground.

Quote Originally Posted by FortyTwoBlades.

The tough heat treatment is not why it got dings. The tough heat treatment is why the blade didn't just completely snap. The real reason it got those massive dings is because there's not nearly enough supporting material behind the edge to keep it from buckling under the impact--i.e. it's ground too thing.

Originally Posted by chiral.grolim.

bass806, before you send the knife in, can you take a micrometer to the blade and measure the thickness of the steel at the back of the dents as well as the distance from the apex to the back of the dent? Tell us if the damage is >1/16" deep and the edge is <0.015" thick.

FortyTwoBlades is correct that the edge is ground too thin, but the Grasso II is advertised as 5160 steel @ 57-58 Rc, and I have read that BRKT outsources the heat-treatment to Peter's in PA, a respected company. At 57-58Rc, 5160 steel at even 0.015" behind the edge should not take such extreme plastic deformation from chopping wood. My guess is that the metal behind the dents is plenty thick for the advertised hardness, but that the edge is NOT actually 57-58 Rc but is closer to 45-50 Rc, over-tempered, perhaps by machine-grinding.

Softer steel requires more material support to prevent deformation, harder steel requires less. Tough steel requires less material support to prevent fracture, brittle steel require more. 5160 @ 57-58 Rc is both hard and tough

Originally Posted by bass806
Ok, first off I didn't realize how difficult it would be to accurately measure the convex edge of the Grasso. The best I can come up with for the actual edge with my digital caliper is 0.013". That is the point that the caliper rests along the edge of the blade. The 0.013" measurement has bite on both sides of the edge(if that makes sense). This is consistent along the entire edge of the blade until reaching the handle area and then it thickens to about 0.014 to 0.015". Of course if you go further into the edge it increases.
The depth of the dents appears to be 0.011" into the blade and the blade thickness at the top of the dents is 0.025". Hope that makes sense.

I agree with the above quoted posts and I measured my BR made Scagel Large Bowie in the same way as bass806 measured the Grasso Bolo.
At 0.011 depth the thickness is 0.0374.
The steel is A2 at hrc 58.
I have chopped with this knife without mercy into frozen 4" Maple and the edge didn't suffer as in the OP's picture.
The thinner BR Rouge did get one roll like the OP's two rolls.
This tells me that a too thin edge doesn't work when chopping.

I am not a metallurgist, but I think a thin edge will be at risk to ruin the heat-treatment if it has been ground too fast.

This seems to my experience with Bark River Knives, disappear with a careful resharpening into unaffected and thicker steel.
This makes the bladeheight lower and personally I don't like that in a brand new and expensive knife!

On a Grasso Bolo, I guess 1/8" lower bladeheight doesn't matter, as it's such a high and massive blade, but on a smaller blade it certainly doesn't add to the look!


Regards
Mikael

 

[lordfriday2]

woops!

 

[Mikael W]

Bass, they will take good care of you. If you get it back and don't like how it looks, give me a call. I'll replace it for you.

This tell tons about Derrick & Wendy and the KSF!

I will put my next order here today.


Regards
Mikael

 

[Dan57]

Why? I like and have used the Gerber for quite a few years with excellent success.

I don't doubt the Gerber's effectiveness. I've just often seen those three, and the first two in particular, touted as the "cream of the crop" when it comes to folding saws. Just a heads up in case you ever want to try something new (and possibly better.) I don't have personal experience with any of them.

 

[bass806]

Next ?, when I send it back to BR- ask for a new knife or have it reground. What do you think would be best so I can continue raking havoc on small tree limbs.

 

[Polamalu]

Next ?, when I send it back to BR- ask for a new knife or have it reground. What do you think would be best so I can continue raking havoc on small tree limbs.

i say get a cpm 3v chopper like the survive knives GSO 10 or the sykco 911. to be honest as long as BRKT does not reground the blade too much you'll be good. but if you don't like how they did it Derrick will be more than happy to replace your bolo. may i suggest that if you go that route have him inspect the edge for thickness before sending it to you so you wont have the same problems.

i wish bark river will make some adjustments to their processes so they wont over heat or thin out the edge on grinding process. also a better QC or retrain people on inspections

 

[Mikael W]

Next ?, when I send it back to BR- ask for a new knife or have it reground. What do you think would be best so I can continue raking havoc on small tree limbs.

A reground into a thicker edge will most likely make the knife perform as can be expected from a chopper.
If You ask for a replacement must be up to You and BR to discuss.
Otherwise You have the promise from Derrick to fall back upon.

BTW just ordered my first machete from KSF, a Fiddleback Forge 12"!

Regards
Mikael

 

[FortyTwoBlades]

A reground into a thicker edge will most likely make the knife perform as can be expected from a chopper.
If You ask for a replacement must be up to You and BR to discuss.
Otherwise You have the promise from Derrick to fall back upon.

BTW just ordered my first machete from KSF, a Fiddleback Forge 12"!

Regards
Mikael

You're gonna' love it. Though my favorite from the Fiddleback line is the 16".

 

[Mikael W]

You're gonna' love it. Though my favorite from the Fiddleback line is the 16".

I hope so!
The FB 12" has got good response and it's a size I can still pack.
We will see if I ever will need a longer machete, but I doubt that!

Regards
Mikael

 

[FortyTwoBlades]

I find 16" to be a very packable size, still, and I practically never go below the 14" mark with my machetes personally--in fact I more commonly use 20"+!

But I'll stop derailing the thread now.

 

[chiral.grolim]

Ok, first off I didn't realize how difficult it would be to accurately measure the convex edge of the Grasso. The best I can come up with for the actual edge with my digital caliper is 0.013". That is the point that the caliper rests along the edge of the blade. The 0.013" measurement has bite on both sides of the edge(if that makes sense). This is consistent along the entire edge of the blade until reaching the handle area and then it thickens to about 0.014 to 0.015". Of course if you go further into the edge it increases.
The depth of the dents appears to be 0.011" into the blade and the blade thickness at the top of the dents is 0.025". Hope that makes sense.

Hmm... those measurements seem a bit off to me... How far back from the apex was the 0.013" measurement taken?

The dents look MUCH deeper in the pictures, at least 1/16" which is ~0.063". 0.011" is so shallow that it would be barely visible without magnification...
Also, if the depth is only 0.011" and the thickness behind the dents is 0.025, then the edge-angle is >45 degrees per side, i.e. 90-degrees inclusive at the apex
I do not believe that.

When measuring edge-thickness on a scandi- or full-convex grind, pinch the blade ~1/16" back from the apex as this is a common edge-bevel width on other knives/machetes/etc. Pinch the blade 0.06" back from the apex. On the Survive! Knives GSO-10, the thickness here (at the bevel shoulder) is ~0.050" which means that the edge-angle is 45-50 degrees inclusive, VERY robust. I would be VERY surprised if BRKT left their edges at a higher angle...

Anyway, I hope that everything works out with the warranty!