Instructables

Profiling a knife shape, from concept to execution.

Picture of Profiling a knife shape, from concept to execution.
As a knifemaker, whether you're a first-timer or a veteran, one of the most basic skills you need to develop is blade profiling. Essentially, that amounts to developing the basic blade shape that will eventually become your finished knife. 

There are two general approaches to making a knife. On the one hand, you can forge a blade from a piece of steel, bending the metal to your will such that it reflects your ability and taste. If you've seen the last Rambo movie, you have an idea of what this entails.

On the other hand, you can do what's commonly known as stock removal, wherein you begin with a piece of raw bar stock and basically take away what doesn't look like a knife.

While both methods are quite effective at producing superior knives - in fact, many knifemakers employ both approaches at some point in the fabrication process - for the purposes of this instructable, we will be focusing on the stock removal method.  

When you finish the profiling process, it should look something like the first picture. 

As we go through this tutorial, you will see some pretty cool tools. If you're lucky enough to live near a Techshop, take advantage of it. I made it at Techshop. They have awesome tools, lots of light, and plenty of space. 

 
Remove these adsRemove these ads by Signing Up
I work with hot rolled steel all the time. The carbon scale comes off relatively easy under a wire wheel on a bench grinder. ;)
atomiccelt (author)  Giesterfarher1 year ago
That's correct. A wire wheel works great... as does sandblasting... or machining with a mill. There are a number of ways to remove mill scale, depending on the type of knife you're making.
Agreed. I'm just partial to the wire wheel because it removes only the scale, not the base metal, and doesn't throw sparks. I get enough of those thrown at me as it is, LOL!

I picked up a 3"x.250"X47" truck leaf spring today, I'm gonna give this instructable a shot, once I get it flattened out. I really like the look of the swords the Spartans used in "The 300". :)
atomiccelt (author)  Giesterfarher1 year ago
When you're working with spring steel, try to find out the type of steel you're dealing with. Ideally, it will be 5160 or 51200. You have to be careful these days, for a couple of reasons. A) Many springs are strange alloys that may not be sufficiently high in carbon content to hold an edge or will be much more difficult to properly heat treat and B) the quality of the steel itself could be suspect. If you're going to use scrap steel, I recommend finding a very old truck spring (pre-1970, or earlier if possible). Hell, if you can find a leaf spring from an old Model A or some old Chevy from the 1940s, that would be ideal.

The other option, which is what I do, is befriend a local springmaker. They ALWAYS have end cuts that they just send to the scrapyard a few times a year.
I did good then. The spring I got came off of a '57 F700 COE.

I'll spark test it when I get it to work tomorrow to determine carbon content.
atomiccelt (author)  Giesterfarher1 year ago
Yes, that sounds quite good indeed.

If I had to guess, you're probably looking at 5160, i.e., 60 points of carbon or thereabouts. If that's right, you'll have perfect steel for a sword or knife.

A word of caution, though. Make sure you thoroughly anneal the spring BEFORE working on it, and again AFTER you shape it (particularly if forging). I tend to put my pre-formed steel through three full annealing cycles before working it on the anvil, and ALL of my blades (forged AND stock removal) through three full annealing cycles before trying to harden.

If you have any questions about hardening steel for blades, let me know. I'd be happy to help.
Excellent! Thank you.
triumphman1 year ago
Have you seen my knives ? I used the Angle grinder for mine! Best tool I ever bought! Thanks for your 'ible !
atomiccelt (author)  triumphman1 year ago
When I first started making knives, I did just like you and used an angle grinder. You can make some great knives that way. I have moved to heavier duty power tools (a 2" x 72" belt grinder - what did I ever do without it?!?!?!) and it cuts tons of man-hours out of the process. I haven't seen your knives yet, but I will check them out as soon as I get some time later tonight or tomorrow. :)