Might as well heat treat it, can't mow with it, it has been raining for the last month or so. LOL. I am on my first knife and I need to heat treat it now, then solder then bolster on. Should I take the edge off of the blade before heat treating, I have heard of the edges warping because they are so thin. I have an oven that will go to 500 and a propane torch. I want to normalize ( I think yoiu would do this first), and temper the edge. Any suggestions
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Heat treating a lawnmower blade?
- Thread starter jmar595
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The onley time i find that normalize does anything is when its a forged knife. normalizing relaxes the steel and releves the stress from forging. but if its a lawnmower blade it might be a good thing to do because who knows what kind of stress it has. how sharp did you make the edge?
Yeah, I have one, throw it away and get some steel that you know what it is. Lawnmower blades I have heard here is not the way to go. There is several other steels that are mildly priced and would make a great knife blade. 5160 is one.
The edge is fairly sharp due to sanding down both sides ALOT. I don't want to throw this one away, I have put an incredible amount of time into. Just want to finish this blade I stared. In the future I will use known steels to make all my knives. I have Wayne Goddards $50 knife shop, he suggested to use the lawnmower blades, so I went to the lawnmower shop and asked for some used blades. He loaded me up with 6 or 7 of em, and told me just to bring them by so he could see what kind of work I do. I since then found out that when Wayne wrote the book the blades were normally made of common steels that were good for knifes, but that today this is not always the case. I will definately use known steels in the future, just have to figure out which ones. I am reading through an ebook, slowly as time arises for it, to learn about steel composition. I really like this knifemaking, and haven't even finished my first one.
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i would just leve the edge how it is. you going to need to resharpen it anyway because heating will remove carbon form the thin edge any way. so if you grind down the edge and harden it you will just have to remove more apon sharpening. ya keep that knife. its a learning process even if the knife does not harden.
Stacy E. Apelt - Bladesmith
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My advice would be to do nothing in the way of heat treating this blade. Sand it down, add a handle,and sharpen it. It won't be much as quality knives go, but it will be your first knife. My first knife was made out of a deer horn and a piece of sheet metal (that was 50 years ago,they have improved since then). I haven't seen that knife in years, but I believe it is still around here somewhere.
Next, you should read up on heat treating and learn how it is done. It requires a heat source that will heat the entire blade to 1500F and hold it there for several minutes prior to quenching. A propane torch would work in a pinch on a small blade, but it is not really the right tool for the job. The tempering oven can be your kitchen oven, it only needs to heat the blade to 350-400F after the quench. See if you can hook up with one of the smiths out your way and get access to some equipment and training. Once you have learned about the process, you will want to build a forge. A simple one does not cost much to build, and will do most all the HT jobs you require at this stage. Wayne Goddard's book is a great starting place, but it is just that - a starting place. Get some other books and read up on the subject. There is a lot of info here and on other sites if you do some searches,too. A good place to find tutorials and forge building info is www.knifehow.com . Also Don Fogg's site has a wealth of knowledge.
Keep working.
Keep learning.
Keep practising.
Stacy
Next, you should read up on heat treating and learn how it is done. It requires a heat source that will heat the entire blade to 1500F and hold it there for several minutes prior to quenching. A propane torch would work in a pinch on a small blade, but it is not really the right tool for the job. The tempering oven can be your kitchen oven, it only needs to heat the blade to 350-400F after the quench. See if you can hook up with one of the smiths out your way and get access to some equipment and training. Once you have learned about the process, you will want to build a forge. A simple one does not cost much to build, and will do most all the HT jobs you require at this stage. Wayne Goddard's book is a great starting place, but it is just that - a starting place. Get some other books and read up on the subject. There is a lot of info here and on other sites if you do some searches,too. A good place to find tutorials and forge building info is www.knifehow.com . Also Don Fogg's site has a wealth of knowledge.
Keep working.
Keep learning.
Keep practising.
Stacy
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- Jun 28, 2005
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- 206
The problem with heat treating old lawnmower blades is you never know what the steel is. So at best you're guessing as to how to heat treat. A lot of modern lawnmower blades are similar to 1080 but not all. The best you can do is take a piece from the same lawnmower blade and test different methode to heat treat.
The propane torch really works better as the heat source of a 1 brick forge. Search for it.
The propane torch really works better as the heat source of a 1 brick forge. Search for it.
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Your going to hear a lot of negatives on mower blades, lief springs, and files, by some well meaning folks who are quite willing to advise you on how to spend your money. I'm only an amateur blade-smith, but I have been making knives for 36 years, and I have made hundreds of blades out of recycled metal. most springs. mower blades and files have enough carbon to make a blade. Most of the time these are simple steels that can be quenched in water. (I use water mixed with soap) Most of the warps and other weird things that metal under stress can due in the quench can be fixed with annealing straightening and re quenching.
That said I prefer to use mower blades for throwing knives and spear heads where toughness is more important than edge retention.
In the picture the top knife was made in the Philippines by a village smith. I got to help on making this knife so it cost me more.
Made from Lief spring. The second knife I made about 15 years ago from a mower blade. Both are well used working knives.
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Heat to non-magnetic, 1450f to 1550f, red to bright red in color and quench in oil or water. Check with a file to see if hard. IF hard, put it in kitchen oven at 400f for one hour. Finish and use it.
A lot more to it than this but, this is a starting point.
Thank you bikermike and Don. This is my first and I just want to complete it, but I want it to hold an edge. I watched Greenpete through a link someone put on here, that was pretty cool. I am going to try the heat treating tomorrow. I have been watching a lot of forging stuff and I am going to make one soon.