Making a Lance

I have a supply of 1080 steel on hand to make points for a variety of bladed items. I like to use 1080 because it tends to be rather inexpensive, easy to work, and heat treats easily. As usual I heat the piece to the Austenite region and then for this steel, a water quench. I follow up with a low temperature (200 C) tempering cycle to stress relieve the steel while still maintaining a reasonably hardened piece. My most recent build was a lance.

I decided on a hybrid form of a Lakota War Lance, and a Zulu Assegai. The total length of the piece including the point is just short of 6 feet. It can be thrown or used from horseback to spear game. A picture of the blade joined to the shaft is shown. I only finished the point to a 320 grit as it will become scratched with use. For a darkened blade you could use a 3-5% Nital etch.

A Custom Knife Progresses

The custom knife I've been making is coming along nicely. I heat treated the blade and did the initial sanding on it. Now comes the making of the handle and attaching it and a hand guard. The first photograph shows the blade after heat treating quenching, and tempering. I used a clay mixture of 1:1:1 of fire clay, #90 sand, and Pozzolana. I cast this mixture and let it cure for 3 to 4 days. A casting fixture is made from wood that is curved to give me a transformed zone of the desired shape. The clay is approximately 3/16ths of an inch thick where I wish the blade to undergo a slower cooling rate.

Custom Knife Failure

Well that didn't go as I'd planned. I was working at the outer edges of the envelope and I went too far. During the quenching process the edge of the blade cracked, rather uniformly down the edge. Given that the crack spacing follows the initial curvature it appears that the cracks were formed in tension in the martensitic portion of the blade. This is not particularly surprising as martensite has a different volume due to the phase change. I had clayed the blade and left the edge exposed to only transform it while keeping the spine of the knife more ductile. This resulted in a overly large curvature and the subsequent cracks. You can see the cracks in the photo.

Making a Custom Knife: Carbon Steel

A gentleman of my long acquaintance asked me to fabricate a knife for the woman in his life. Since I only do blade work for myself or close acquaintances this posed an interesting problem for me. There can be a certain intimacy in making a blade for a person as what their needs are becomes important in the overall design and can be answered only by rather personal questions. I am not in the habit of asking other women personal questions but accrued obligations are the sine qua non of my life so I accepted.  Having said that I'll walk through the process to get it clear in my own thoughts. For working with steel there is one diagram that should be engraved in the mind. The Iron-Carbon Phase Diagram.