Cliff Stamp vs machetes

firkin · Mar 23, 2002

Thought this machete testing might be of interest to some khuk owners:

Gruesome result:

http://www.physics.mun.ca/~sstamp/images/patrol_machete_broken.jpg

Seems that this occured limbing a small, dry pine, not a torture test.

Thread is here:

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

there's also a small amount of khuk content:

"I was also working with the HI Sirupati at the same time and it was very fluid, no binding, and am now very interested in a Kobra. "

Rust · Mar 23, 2002

That mess looks like the result of bad heat treatment to me - all harden, no temper. Any other opinions?

firkin · Mar 23, 2002

I would hope that's some kind of one-time manufacturing screw-up....The thought of removing that suddenly unconnected tip from me or somebody I was working near is pretty unsettling though.

Bill Martino · Mar 23, 2002

I hate to see failures like that no matter what or whose knife it is.

redvenom · Mar 24, 2002

A hairline crack in the steel?

I have the remnants of a flea-market parang in my storeroom somewhere where the tip broke off about a third of the way from the point. There was a crack in the spine in that area which gave way as I was cutting into a coconut tree. That was the last time I ignored cracks or fractures in my tools...

Andrew LImsk

firkin · Mar 24, 2002

I hate to see failures like that no matter what or whose knife it is.

Amen to that. Scarey stuff. And the very few people in the world that I wouldn't mind seeing it happen to deserve worse......

Bill Martino · Mar 24, 2002

A fracture is the beginning of the end. A foldline is a completely different story.

Bill Siegle · Mar 24, 2002

not offering an excuse but would say that below zero temp helped things along too. I have seen super tough steel break like glass at low temps. A friend of mine once lost all the springs on his power hammer when he forgot to warm them. He said he got almost 2 whole strikes out of them before they blew. They were 5/16 thick and stacked 3 deep too. As to the small pine being the culprit, again I say temp was a facter. Frozen sap and wood can be like rock.Very hard on cutting tools. Just my $.02

Cliff Stamp · Mar 25, 2002

The edge deformed as it was really thin. The blade was less than 0.020" thick behind the edge bevel, and the primary grind was full flat, ~2" wide on 3/16" stock. The reason it cracked instead of ripped when the bend was further impacted is that this is a high carbon tool steel, fully hardened at ~59 RC. This is in a very different league than a differential tempered piece of spring steel.

The Sirupati is still going fine, having seen years of use, in colder weather. The handle is getting a bit loose, I will have to re-glue that eventually. The blade also has a small impaction notch up near the tip when I whacked it off of a piece of glass clearing some brush. Try that some time if you want to see some edge damage. My 18" AK is likewise perfect, having been retired though in favor of the 22" version, enough warmup, time to use the real thing.

-Cliff

Bill Martino · Mar 25, 2002

Thanks for more valued input.