making blades from 12in concrete saw blade?

O

ouporblowup

Joined
Feb 6, 2011
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im new to knife making and dont have money for materials so i was wondering if this would be the right type of steel or not?
 
i thought the same thing until i found out the steel used is not really that good since the diamond coating is what does the cutting. i had a 2' concrete saw blade and thought it would make good machetes.
 
Almost a guarantee that it is a low carbon steel. I have a bunch of those blades...all are of no use for blades.
 
In my humble opinion, always know the type of steel you are using when making a knife. Steel is not that expensive and if you are going to spend 15 to 30 hrs making a knife, you should know the steel for specs on heat treatment.
 
Yup. You'll be much happier in the end if you just spend $5 on a piece of known good cutlery grade steel like 1084 and have a maker near you help you heat treat it. That $5 investment in good steel will likely result in a knife that can outperform anything you've ever used before. No joke.

five dollars. We're all broke, but nobody is that freakin broke.
 
FWIW, few modern circular saw blades are good knife steel.
If you need more info, please refer to nathan's post.
 
this question comes up with regularity... I had one of my brands of 12 and 14" diamond saws (I use hundreds of them in my other life) tested, less than 0.3% carbon, though they do harden in water not as much as normally desired for a knife

They make good washers if you ever need 12" washers, or you can stick them under your sidestand for your motorcycle to rest on in the forest, I have enough to stack them into weight plates for a barbell should I ever find time to workout
 
I've been making knives successfully from concrete saw blades for over 10 years. Before that I used a lot of files and lumber mill blades. One thing I have learned is that each saw blade is different from the next. But generally I find that you can make good knives from MOST of them. Since I have a unlimited supply and enjoy playing with steel, I don't mind experimenting. Before I start making blades out of one, I cut test strips and quench them. I do break tests and examine the grain, grinder tests and watch the sparks, comparing to known samples of other steel I keep around, file tests, punch tests, and drill tests. Once I'm satisfied that it's good enough quality to harden consistently, I start making blades. I cut it into rectangular blanks and anneal them overnight. I use the stock removal method to make my blades. When they're done I normalize 3 times, taking to critical and cooling in still air. Then I quench in peanut oil 3 times, edge first. Finally, I differentially temper with a fine propane torch flame to color. I'm sure any number of these steps can be met with criticism from others, but what I do know is that it works for me. My knives perform well, sharpen well, and are good enough to get me repeat business. The key is proper heat treatment, and I've simplified it a bit in my explanation here. There are a lot of subtle points to doing proper heat treatment that end up being instinct and a good eye from years of experience and can't always be conveyed adequately. I have thrown many a ruined blade into the wall with frustrated curses because I couldn't get it right. I have a graveyard of twisted blades to prove it, but hundreds of successful knives in the woods and the kitchen as proof that this steel is certainly usable.

Most of the blades I get are much larger than 12" or 14". I think mine are mostly in the 28" to 30" range, with the steel being 3/16" thick. I get some smaller ones that are 1/8" thick, and I use some of those too. If you can find one brand that works well, try to stick with the same kind and you'll get consistent results. As a maker, don't ever let someone else tell you "that won't work". Prove it yourself.
 
I won't weigh in on the question of whether saw blade steel is usable. I will say that I have noticed in my time on this forum that there are several makers here who will provide a newbie with a free piece of cutlery grade steel for making their first knife. You have probably already received such an offer. My advice... take them up on it.

You can try the saw blades too, if that's really important to you, but don't pass up a no cost opportunity to see how things can be done with proper materials. Perhaps then you could do a side by side comparison and see which you like better then come back and report your findings.

As an aside, if you want a block of wood suitable for knife making, I'd be happy to send you one. Lord knows I have more than I'll ever get around to using.
 
Tryppyr, I agree with you 100%. My particular path in knifemaking just happened to lead me down the road of using sawblade material. I have also used "store bought" steel. I think I enjoy the challenge of making something usable out of junk, so that works for me. The purists frown on my approach, saying that I won't get consistent results. Like I said, the key is knowing the properties of the steel you're using, which you can do using the right techniques. By all means, newbies should try both, especially if it's free!

And I'm always looking for handle materials. I'd love a piece of wood, especially if it's exotic or interesting hardwood from some country that I can't pronounce the name of. I use wood on virtually every handle I make. What kinds do you have?
 
BluesHarp, I am all for using free junk steel to mess around with and practice with as I have said before. Selling knives made from mystery steel is another matter and I hope your customers are aware that you are using saw blades of mystery steel to make there knives. But this is really none of my business and I'm not trying to flame you or anything. Do what works for you.

But I would like to point out that you said "The key is proper heat treatment" and "the key is knowing the properties of the steel you're using". If you are using mystery steel, you don't know the properties of the steel and thus can not do a "proper" HT. The techniques you are using to determine the steel will only get you in the ball park at best, though you may get personally satisfactory results, it seems your statements are a bit contradictory to your actions.
 
I should have said, "the key is learning through empirical observation what the nominal characteristics of the steel are, and deeming it fit based on your own standards." While I may not know the exact carbon or molybdenum content of the steel, I know whether it's fit for making a knife or not, based on 20 years of making knives.

If it hardens, keeps an edge, and won't break under normal use, why do I care? What more does a knife have to do? I'm not in any kind of competition, I just make tools that work.
 
Good points BluesHarp, proper testing is the key whether using known or "unknown" steel.
It is very easy to make a useless knife out of high quality known steel, if your heat treat process is incorrect
and you don't take time to properly test your knives.
 
I recently received a knife from a maker who told me it was made from a bandsaw blade that he "believed" to be L6.

The knife came with a phenomenal edge, perfectly symmetrical, a very keen angle, and was popping hairs like crazy.

The knife also very easily push cut rope and paracord, and sailed through paper and cardboard.....

For all of about 15 or 20 cuts.

Now I can barely cut paracord with it.

Now, I don't know anything about the specific HT process that the maker used, but it just goes to show you that initial results can be deceiving. A properly HT'd L6 blade should still be popping hairs for what little I've been cutting with it, much less a piece of paracord.

Personally, I view it as practically paying myself when I spend a few bucks on a quality known tool steel and heat treat it to known specs in a controlled process with professional quenchants. No guesswork or arbitrary file or spark tests needed. I know I'm getting the most out of my steel every time. I can then sell a 1095 blade that I know is going to perform like a 1095 blade. Plus, I don't have to spend hours worth of my time doing "test treats" and throwing away blades that didn't make the cut or that will likely still perform sub-par to a high carbon tool steel of a known chemistry.

Now all that being said, maybe those saw blades are made from 10xx, 5160, L6, or another premium tool/blade steel.
What do I know.
 
You can make a knife out of old concrete saw blades if you want to. It will likely get sharp and cut, but not for very long. People made (and still make) knives from hammered copper. You just have to know why you want to do it, and be reasonable in your expectations of it's ability. Is it just for fun, to recycle material, to make due with what you have, curiosity, etc. I have a large concrete saw I fully intend to make a knife from someday. I understand it won't be the best, or the prettiest, it may bend when I use it, but in the end, I understand the limitations, and still want to do it. I also have some A2 and M2 that I plan to make knives from, and I expect a lot more from them in terms of edge holding and behaving like a knife.
 
Well, all I can say is that this thread popped back up after six months with only one person claiming good knives from concrete saw blades. If you get good knives from 4140 or lesser grade steel, I commend you. Just imagine what you could do with real knife blade steel !
 
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