Knife Material

[missionary5155]

Good morning
Would you consider Leaf Spring as a sutible material to make a couple simple knives of about the Colonial period ?
This is something I can do down here that is not Regulated or liscensed.
Mike in Peru

 

[50cal.cliff]

Don't quote me on this as I am not an expert by any means. Wick Ellerbe would be the man to ask for sure on this. He is a member of this forum and a knifemaker.
Alot of folks will tell you are making knives from a mystery steel if you don't now exactly what the designation of the steel is. If you are fimailar with the spark test you can tell alot by hitting it with a grinder.This is a link to how that works supplied by Wikipedia. http://en.wikipedia.org/wiki/Spark_testing_metals
Having said that, most of the older and some of the newer springs are made from a steel called 5160 which is good for making knives. Especially larger knifes such as Bowies.

 

[paulvallandigham]

I made my first knife from a leaf spring out of a 1930s vintage auto. The leaf springs today are made from different steel and are a lot thicker than that one was. Today, you would have to cut out a piece of the spring, anneal it, and then forge it to shape, thinning it to a manageable width. A heavy blade will be no more than 3/16", while a thinner blade can be from 1/16"- 1/8" in thickness. Fine blades in pocket knives will be even thinner than 1/16". You can make blades from very thick steel, but the knives are a bit ' clunky", usually don't balance well in the hand, and the thickness makes it more difficult to put a very sharp edge to it.

If you are going to forge steel, you might be better off using Coil Springs from cars today, than using flat springs.

Best wishes.

 

[ameling]

Leaf springs can be made up into good knives. But so much depends upon the actual steel alloy it is made from and how thick it is to start with.

Leaf springs in ... general ... are either 1085 or 5160 steel. The older ones are more likely the 1085 carbon steel, while more recent ones are more likely the 5160 carbon/alloy steel.

I would also recommend that you go look for some lawn mower blades - the common gas powered push mowers. Those blades are generally also made from 1084 carbon steel or 5160 alloy steel. And they can be made up into good knives. You can also generally get old/used blades for free. But you could also buy a new lawn mower blade to start with.

They tend to be between 1/8 and 1/4 inch thick, with 3/16 inch thick being very common. And from 1 1/2 inches wide up to 3 inches wide - with 2 or 2 1/2 being pretty common. Lengths generally run between 18 inches and 24 inches.

But you will have to work around those blade mounting holes in the center, and any numbers/letters stamped into the blade by the manufacurer. But they are a good source of cheap material to start playing around with for knife making.

Hope this helps.

Mikey - that grumpy ol' German blacksmith out in the Hinterlands

 

[missionary5155]

Thanks Fellers ! Leaf spring steel is readily available here in all sorts of thickness. Here (Peru) vehicles were imported from everywhere. Mostly Oriental now. NO mower blades here.
Well that will get me headed on.
Mike in Peru

 

[LRB]

Much would depend on how good of a blade you would settle for. Early knives were usually of lesser carbon, and less hard than we like today. Most any steel capable of being a spring will make a knife. Some would be better than others. In your case, just pick one and go with it. When it comes time to heat treat it, get back to us. If possible, or practical, contact the auto manufacturer and ask what it might be. The 1085 mentioned would be very good by any standard. 5160, ok, makes a good chopper, but a bit lacking in edge holding. By todays expectations anyway. 1095, leave it alone!

 

[Jblk]

A good rule of thumb to use in selecting unknown metals for a project is to find out what the metal was used for originaly.The spark test is probably one of the best indicators of carbon content.All of the blacksmith shops that I saw as a young boy always had a large pile of scrap metal to be fashioned into new tools.