Steel and blade destruction tests ??

[Dr Feelgood]

I always hear that you have to do all sorts of tests of your steel and destroy thousands of dollars worth of blades to really learn what the steel is doing.

ummmmm I dont want to destroy thousands of dollars of blades to retest whats already been tested... just my opinion.

Lots of tests have already been done by many master blade smiths as to how the steel will react to different heat treating techniques and such. So is there a database where new makers like myself can read the tests and results and if there isnt .... why ??

 

[Hesparus]

1) It's important to know what you're getting out of your heat treating. Even if you're using a top of the line oven and fancy quenching oil, results can vary with the conditions in your shop. You need to know what you're getting out of what it is that you're doing.
2) Steel and heat treat aside, blade shape and edge geometry are going to affect performance. It's possible that your blade shape or finish is creating stress risers that will make your blade prone to breaking in certain places under certain types of uses. You may be grinding too thick or too thin to achieve the performance you want given your heat treat.
What other people have found can be an invaluable tool in finding a starting place and general rules (and mad props to the people who spend their time doing lots of testing), but you won't know what your knives are capable of or what their strengths and weaknesses are unless you find out.
That said, you don't need to destroy your knives to see what they can do. Tests like rope cutting or chopping wood can give you good information about how you're doing.

- Chris

 

[Dr Feelgood]

Wow I never looked at it that way. I planned to do some tests just out of general curiosity.
Thanks!

 

[Hesparus]

Glad I could help!
To elaborate just a little bit, I would like to see some compilation of the steel types, edge thicknesses, geometry, and target hardness that people use for different types of knives, just so it would be easier to ballpark. But there are way too many variables working against eachother to eliminate the need for your own testing.


- Chris

 

[me2]

I always hear that you have to do all sorts of tests of your steel and destroy thousands of dollars worth of blades to really learn what the steel is doing.

I think it's a little overstated. There are only a handful of makers that promote going to that extent. Thousands of dollars worth is a bit high. You do need to test your blades to see if they do what you want, and that may involve a destruction test, but I'd say 3 or 4 knives will give you a good idea. If you want to destroy every 10th knife, that's up to you, but once you get control and repeatablility of what you're doing, it shouldn't be necessary. More destruction tests on more steels than you can imagine have already been done. You just need to know where to look and how to read the results. Start with Verhoeven's book for bladesmiths. You can probably still find it on line. You need to have a clear idea of what your knives are supposed to do. That will give you an idea of what data you should seek.

Edited to add that I'm assuming 3 or 4 of your knives would not cost 1000's of dollars. If so, well, you may just have to make the sacrifice.

 

[Kevin R. Cashen]

Dr, I hear where your are coming from. Sighting in your knifemaking recipe is not much different than sighting in a rifle scope. If you can manage a tight consistent pattern it is just a matter of a couple fine tuning clicks one way or another. If however you have a scope that rattles loose every other shot then you are going to spend a whole lot of money on practice ammunition keeping it on target. Anybody who has successfully done it will tell you that the most effective way to troubleshoot something is through complete accounting for the variables and changing just one at a time, this can only be done by having knowledge and control over the process. The alternative is endless trial and error, for some that is the fun of it, for others that is the bane of them attempting to eke out a living making knives.

If you have control with good materials and methods that will not continually change or add variables on you, your time spent in testing can be greatly reduced with confidence. If you don’t, the only safe way to assure quality is to test as much as necessary, even to destruction if you are not fully confident of your process. You can just make a knife and then deconstruct it to determine if your process still works or you can plan a process to make the knife you want and then assure the results are what you expected. Both approaches have the same goal in mind; you just have to determine which one suits you.