Thread: Does anyone else shave with old car springs?

I have a bunch of Nepalese khukuris made out of German lorry leaf-springs. But no razors, as far as I know.

Interestingly, I recently saw a Walter Sorrell’s knife making video
“Can I make a knife from a lawn mower blade?”

“The short answer is yes… maybe. See, a GMC 3500 leaf spring is not the same as a Volvo truck spring. You have to do some testing.”

(Making a Carpenter's Marking Knife)

I would love to see some photos of you guys' homemade (apologies if that is incorrect nomenclature) razors. I've thought about different things that may be made into a razor but I lack a couple of necessary items - skill, time, patience, equipment....

Originally Posted by 5G62

I would love to see some photos of you guys' homemade (apologies if that is incorrect nomenclature) razors. I've thought about different things that may be made into a razor but I lack a couple of necessary items - skill, time, patience, equipment....

These are all made from car/truck springs. EDIT: I guess that one of them was an old harrow blade.









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Hey, what about railroad spikes? I just thought about that because my son has one that is all bent but it looks like it's about 3/4-in square and about 8-in long.anyone ever tried that? I don't know if that steel is any good or not. Just a thought.

Originally Posted by PaulFLUS

Hey, what about railroad spikes? I just thought about that because my son has one that is all bent but it looks like it's about 3/4-in square and about 8-in long.anyone ever tried that? I don't know if that steel is any good or not. Just a thought.

Typically railroad spikes are a medium carbon steel and are not recommended for blades. They are popular as "blacksmith" knives, but those who are serious about it will forge weld a better piece of steel into the edge. That being said, I think that "softer" steels may work quite well for a razor as long as they are "hardenable". You should try one and let us know

Just found some one with a coil spring he's willing to give me. Any tips on hardening/tempering you can share? I've made one knife and some punches but not a razor. The tempering scares me. (all i have is a toaster oven and forge.)

Originally Posted by tintin

Just found some one with a coil spring he's willing to give me. Any tips on hardening/tempering you can share? I've made one knife and some punches but not a razor. The tempering scares me. (all i have is a toaster oven and forge.)

All I have is a toaster oven and a forge as well. I've spent many years in a factory that heat treated metal. One of my jobs was to calibrate all the instrumentation, write the calibration procedures and then train the technicians on how to perform them. I say all that because I take the exact opposite approach with car springs and old farm steel. If I am making a knife out of D2, 440C, 154CM or some other alloy, I know enough to send it out to someone with a digitally controlled furnace.

But if I am forging old carbon steel into a blade, part of the mystique about it is to heat treat it by "feel". I want to get consistent with making a good blade the old fashioned way. So you may or may not want to listen to how I heat treat car springs. You can certainly get a good heat treat with a forge and a toaster oven if you are using a car coil spring and it's not that hard to do. It does take a bit of practice though, so pound a couple of pieces flat and polish them up. Then use those as practice before doing it on a knife or razor that you have already put hours into. If you want to know my techniques, I'm more than happy to share them. I just wanted to post a quick disclaimer.

I'll take all the help i can get. i won't hold you responsible for my failings

Originally Posted by tintin

I'll take all the help i can get. i won't hold you responsible for my failings

Okay, here is how I do it. As a further disclaimer, I would only use this on a basic carbon steel. Basic carbon steel is forgiving and can produce good results even if your procedure or your temperatures are a little off. I can get good results with the procedure below using car springs and old farm steel (1075, 5160, etc...). Steel such as 1095 and O1 produce hit and miss results with this for me, so those I would do in a digital furnace.

* First is to dim the lights. My forge is in the barn, so I turn off the overhead lights and turn on some small wall lights on the other side of the room. I want to be able to see the colors well. The apparent color of the steel to your eyes will vary greatly based on the ambient light. So figure out a lighting scheme that will be consistent from session to session. This was the biggest reason I moved my forge inside where I could control the lighting.

* Second is to figure out temperatures. Now you can go buy a pyrometer for pretty cheap and that is probably the wise thing to do. Even if you want to learn how to tell temperature by color, a pyrometer is a good idea. 30 years ago when I started this in my parents back yard that was not an option, so I went with the magnet and salt option (which I still use). Iron becomes non-magnetic at about 1,400 degrees and salt melts at 1,475. So play with the steel color, the magnet, salt and the pyrometer so that you can get a good feel of what color equates to what temperature.

* Third is to normalize the steel. I do this with three heat cycles. First heat it up to 1,500 (Just past the salt melting on it) and let it cool back down to black. Second heat it up to 1,400 (Just as it turns non-magnetic) and let it cool back down to black. Third heat it up to 1,300 (You will have to do this by feel or use your pyrometer) and let it cool down to black.

* Now for the hardening. Heat it up to 1500 (after the salt melts) and then plunge it in oil. With basic carbon steel (1084 and down, 5160, car springs, etc...) it is better to be a little on the hot side instead of the cold side. That being said, you want an orange color, not yellow. Yellow is too hot. Again, play with some scrap pieces and your pyrometer. For oil you can use vegetable cooking oil. That is cheap and smells good. Used car oil also works but doesn't smell as good. I have bunches of free used car oil and I'm out in the barn so that is what I use. The blade should be hot enough that the oil is just on the point of catching fire when I plunge the blade into it. Don't swirl the blade around as that can cause it to warp. Just hold it still and keep it in there until you can put your finger under the oil and touch the steel without getting a blister. When you pull the blade out of the oil, the scale should be flaking off. Rubbing it with a paper towel or a wire brush should remove most of the scale. If it doesn't then it probably wasn't hot enough when you put it in the oil. If you have ever watched Forged in Fire, then you already know about the file test. I do the file test as well as the spark test on the belt grinder. The belt grinder spark test is a much better test for me than the file is. With a sharp 120 grit belt, I can not only see the difference is the sparks, but I can also feel the "pull" of the belt against the steel. If it is hardened, there will be lots of little sparks and the belt will skate off the steel. As soon as you move to a non-hardened area of the steel, the sparks will change drastically and the belt will grab the steel and want to pull the blade out of your hand. It's pretty amazing actually and is a great way to check for soft spots.

* Finally is the tempering. This is easy. Get your little toaster over to 450 degrees. Use an oven thermometer or your pyrometer to verify the temperature. The dial on the toaster oven is anything but accurate. Cook the steel at 450 for one hour. Then remove it for ten minutes. Cook it a second time for one hour. Now you are done and it is time to go back and finish grind your blade