Hey Cliff, have you gotten your BK9 yet??

Yojimbo · Aug 7, 2002

I got mine last week and I'm very happy with it so far.

I can't wait to see what happens when you put the hurt on a BK9. Do you plan to chop and concrete blocks or nails? How about serious bending tests?

Given what you've already done to the BK7 what are your expectations from the BK9?

Regards,

Chris

ExamonLyf · Aug 7, 2002

I hear Cliff just ordered 64' of #4 Re-bar Jimbo.., so "buckle-up"

"Hunters seek what they [WANT].., Seekers hunt what they [NEED]"

Cliff Stamp · Aug 9, 2002

Yojimbo :

Do you plan to chop and concrete blocks or nails? How about serious bending tests?

Yes.

... what are your expectations from the BK9?

It should be a very solid performer based on its geometry. My only concern would be with possible brittle failure as it is a lot longer and heavier than the CU7 so impact shock is going to be a lot higher, and could lead to problems like I saw on the Patrol Machete.

-Cliff

Yojimbo · Aug 9, 2002

Originally posted by Cliff Stamp
Yojimbo :

Yes.

It should be a very solid performer based on its geometry. My only concern would be with possible brittle failure as it is a lot longer and heavier than the CU7 so impact shock is going to be a lot higher, and could lead to problems like I saw on the Patrol Machete.

-Cliff

Did you ever complete the testing on the Patrol Machete? I remember reading you broke two of them. Is is possible the PM's you broke were not heat reated properly or do you feel the steel had really reached it's limits with that design?

Thanks,

Chris

Cliff Stamp · Aug 14, 2002

Yojimbo :

do you feel the steel had really reached it's limits with that design?

It depends on what you use the blade for. It worked fine on light vegetation, and hard wood chopping is very hard on a blade. The edges on mine were from 0.018 to 0.022" thick in the hump, and since it was a full flat primary grind of about 2" wide, this meant the edge had little to no support. Once the edge gave way under lateral stress, the primary grind would collapse as well.

The fact that the edges got damaged given that profile doesn't surprise me, nor would I look at it as a negative aspect as that is simply a very thin cross section for that type of work. I don't know of any custom maker who would bet on one of their blades performing at the same specifications. I would expect rippling no matter what steel was used. I am of course willing to be proven wrong here, but I have yet to see anything promoted to that level.

However, the steel should not have cracked as it did. This can be a subject of some debate, but my perspective is that blades of this class, when pushed to failure should do so as the edge did on the Valiant Golok. Ref :

http://www.bladeforums.com/forums/showthread.php?s=&threadid=210810

Now this is a different primary grind, but the steel is what prevents fracture propogation.

-Cliff

Yojimbo · Aug 15, 2002

Cliff,

I forgot ask, when's the E.T.A. on the BK9 review?

Thanks,

Chris

Cliff Stamp · Aug 15, 2002

Andrew Lynch will be looking at it first, so it will be awhile.

-Cliff

FK · Aug 16, 2002

It should be a very solid performer based on its geometry. My only concern would be with possible brittle failure as it is a lot longer and heavier than the CU7 so impact shock is going to be a lot higher, and could lead to problems like I saw on the Patrol Machete.

-Cliff
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The testing of the Patrol Machete was on frozen wood if I remember correctly. This hard chopping on a very hard medium will give a severe impact shock which is not realistic for comparison testing. Not surprised the PM chiped out and failed.

Regards,
FK

Cliff Stamp · Aug 16, 2002

FK :

The testing of the Patrol Machete was on frozen wood if I remember correctly.

No it was actually in the short period of time when everything around here isn't frozen. Ref :

http://www.bladeforums.com/forums/showthread.php?s=&threadid=194054

This hard chopping on a very hard medium will give a severe impact shock which is not realistic for comparison testing.

It would be if you did the same thing with other blades. You could argue it was beyond the use limits of course, but if it failed and another didn't, that is a pretty decent argument for a relative durability comparison.

-Cliff