Edge testing, How do you do it?

[KenOnion]

Since Howard asked what your favorite working knife steel is I thought I'd ask what method do you use to test your knives for edge retention,Impact resistance etc...
I know of the rope test and 2x4 chopping which I personaly dislike as it really proves little .Looks cool though!
I like to clamp my test blades in a vice edge up and using a piece of rattan approx 2# accross whack the cutting edge to test for immpact resistance .And smacking and rubbing the cutting edge with the rattan back and forth to test edge retention. I use other methods as well however this is a standard test of mine. what do you do?

 

[Mike Turber]

Ken,

I have been doing a very simple test for years with great success. When we get in a new knife I start using it in our warehouse cutting up cardboard boxes. There is not much harsher testing then cardboard and it is a real world test.

I now even apply a bit of science to it. I mount a knife on a guide which will keep the same angle and portion of the blade in contact with the 200# test cardboard. I continue to pull the blade through until the cardboard starts to buckle under or it gets to the point where you can no longer pull it through. I measure the distance in inches and this becomes the knife's score for this portion of my test.

In another test I have a 2lb ankle weight mounted on a bo staff. I place one end of it against the back of a board mounted to a table. I mount the blade in a vice much like you do. I drop the bo staff at 3ft above the table directly on to the blade while it follows a guide down to make sure it hits the same spot each time. I then do the classic fingernail pull looking for burrs. This test usualy tells me how long a knife will hold up in chopping tests and can be repeated. I do go through a lot of bo staffs in this test and I am thinking of switching to broom handles to save $$$.

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Best Regards,
Mike Turber
BladeForums Site Owner and Administrator
Do it! Do it right! Do it right NOW!
www.wowinc.com

 

[RMLamey]

After putting a solid working edge on the knife, i walk out the front door of my shop into the woods and start hacking. Usually start with some small saplings, then move to large limbs, then finally to a fallen oak tree that is old and hard.

This gives me a good indication of overall edge retention and strength. It has kept me from selling a few knives that were not worth hanging on a belt.

Jerry Fisk does some good (and impressive) testing on his video, he also has a new video coming out with alot more testing on it.

 

[Joe Talmadge]

When evaluating an edge, I do a number of tests. I pick the tests based on whether they make sense for that particular knife.

Whittling - good performance here means the edge is very thin (spine thickness doesn't matter). Hard whittling for a few minutes also shows any handle hot spots.

Chopping - I do this in both soft and hard woods, to test both edge durability, edge retention, and chopping efficiency. Also a good test of handle hot spots.

Cutting cardboard: speaks to edge geometry, overall blade geometry, handle hotspots, and edge retention.

Slicing rope: I strongly disagree this is not a useful test. In fact, I have NEVER had a knife that does good on this test not do very very well slicing in the field. I try on both soft and hard ropes, but emphasize the hard rope. Bad edge geometry (or too-polished an edge) will simply skitter across the top of the rope. Good edge geometry will slice through. I try this with both the original edge, then I rough the edge up to see what the difference in performance is with a coarse edge. Do this for a while and it also measure handle hot spots. Again, if I can get the knife to cut well through very hard poly rope, it will typically kick-butt in the field on all slicing jobs. On soft rope, I like the see the knife push-cut through rather than slice, but if it won't push cut I'll slice.

Chopping food: I look for accurate, controllable, easy cuts through soft and hard food, edge retention and durability on the cutting board, etc.

Other food prep: Cutting raw or cooked meat, etc.

Joe