(M) Posted January 27, 2018 Share Posted January 27, 2018 Hey everyone, i have some leaf springs that i picked up that i want to practice on. I know a place where i can get unused ones too so there are no fractures. I have a charcoal forge and am building a propane one soon. I am very beginner and i have made one small pipe wrench knife so far. What tips do y'all have for forging leaf springs? I also plan to pick up some more reliable tool steels like 01 for practice. Also one more question, does burning high alloy chromium steel have create deadly chromates? I know chrome coatings are deadly for that reason Quote Link to comment Share on other sites More sharing options...
Joël Mercier Posted January 27, 2018 Share Posted January 27, 2018 Hi M. I would cut your leaf spring in 1" strips length wise depending on its thickness, for forging hunting knives and such. Try starting with small knives. Once you've successfully forged and heat treated a few, you can try bigger and bigger. O1 tool steel is not a beginner's steel. It requires a soak at precise temp to get the most out of it. New spring steel is ideal. Other great steels for beginners (and pros) are 1080, 1084, 1085, 80CrV2, 15N20. Steels to avoid when beginning are O1, W1-2, any stainless unless to send for HT, 1075, 1095. I would also take the opportunity to tell you about using decalescense for heat treating your blades. This is the best method for heat treating simple carbon and low alloy steels. It's a change of state in the steel that occurs right before the ideal temp to quench the steel. It is very precise, you'll just need to practice it a few times at night. You need very dim lighting or complete darkness to see it. Watch YouTube videos about decalescense. Quote Link to comment Share on other sites More sharing options...
(M) Posted January 27, 2018 Author Share Posted January 27, 2018 Thanks! The steel has been hard to hand work by hand. I plan on getting someone to strike for me. About the 01, i have beed reccomended it as an excellent beginner steel numerous times. Not sure whats going there Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted January 27, 2018 Share Posted January 27, 2018 wait until the O1 air hardens on you at the anvil... Quote Link to comment Share on other sites More sharing options...
Joël Mercier Posted January 27, 2018 Share Posted January 27, 2018 On 1/27/2018 at 3:46 PM, (M) said: Thanks! The steel has been hard to hand work by hand. I plan on getting someone to strike for me. About the 01, i have been reccomended it as an excellent beginner steel numerous times. Not sure whats going there O1 is very forgiving in heat treatment. It's just that if you don't use the correct technique, it will not perform as good as it should. So why use a steel that is more costly than others when you can't get the most out of it and it will most likely perform equally to cheaper, perfectly heat treated steels. On 1/27/2018 at 3:46 PM, (M) said: The steel has been hard to hand work Try to forge it a bit hotter but 5160 is a harder to forge than 1084. Quote Link to comment Share on other sites More sharing options...
Tubalcain2 Posted January 27, 2018 Share Posted January 27, 2018 On 1/27/2018 at 3:36 PM, Joël Mercier said: O1 tool steel is not a beginner's steel. It requires a soak at precise temp to get the most out of it. New spring steel is ideal. Other great steels for beginners (and pros) are 1080, 1084, 1085, 80CrV2, 15N20. Steels to avoid when beginning are O1, W1-2, any stainless unless to send for HT, 1075, 1095. Why not 1095? that was the steel I used on my first knives, and I have found heat treating it to be pretty simple. Quote Link to comment Share on other sites More sharing options...
Joël Mercier Posted January 27, 2018 Share Posted January 27, 2018 Just now, Tubalcain2 said: Why not 1095? that was the steel I used on my first knives, and I have found heat treating it to be pretty simple. How did you heat treat it? Quote Link to comment Share on other sites More sharing options...
Tubalcain2 Posted January 27, 2018 Share Posted January 27, 2018 Brought up to critical, did an oil quench, tempered for an hour at 375. This was a couple years ago when I was first starting out. With what I know now I would do 2 tempering cycles at a higher temp, maybe 425. That said, I beat that blade around pretty bad and never had any issues with it. Most of my metallurgy at the time was based of off the 50$ knife shop book. Quote Link to comment Share on other sites More sharing options...
Joël Mercier Posted January 27, 2018 Share Posted January 27, 2018 Don't want to be a xxxxxxxxx here but hypereutectoid steels require a soak a critical to dissolve the extra carbon into the solution. The way you heat treated it left out the extra carbon so your 1095 most likely performed like 1084 with a shallow hardening. Quote Link to comment Share on other sites More sharing options...
Stormcrow Posted January 27, 2018 Share Posted January 27, 2018 5160 is readily available new, and the price ain't at all bad. Assuming USA, of course. Shipping will be a bit pricey. If you're worried about chrome in fumes from 5160, I have never heard anything ever mentioned about it, and it is a widely-used blade steel that is forged. It is going to be stiffer under the hammer than plain carbon steel like 1084. Learn hammer technique. Proper hammer technique will make a tremendous difference in how you are able to move steel without a striker or power hammer. Here's a video on my technique, there are other methods. Don't try to work it too cold. You're making it more difficult to move under the hammer and potentially introducing dangerous stresses in the steel. You can hammer at a lower force at a lower temp to smooth out hammer marks at the end, but if you are trying to move the steel you need it hot. Quote Link to comment Share on other sites More sharing options...
Tubalcain2 Posted January 27, 2018 Share Posted January 27, 2018 1 hour ago, Joël Mercier said: Don't want to be a xxxxxx here but hypereutectoid steels require a soak a critical to dissolve the extra carbon into the solution. The way you heat treated it left out the extra carbon so your 1095 most likely performed like 1084 with a shallow hardening. OK, wow. You obviously know a lot more on this subject than I do. hypereutectoid? could you explain this term? Could you also explain soaking? I have heard the term bandied around, but I don't know that I understand it Quote Link to comment Share on other sites More sharing options...
Joël Mercier Posted January 27, 2018 Share Posted January 27, 2018 1 minute ago, Tubalcain2 said: OK, wow. You obviously know a lot more on this subject than I do. hypereutectoid? could you explain this term? Could you also explain soaking? I have heard the term bandied around, but I don't know that I understand it The eutectoid point (0.84%) is the point of carbon "saturation" in the steel. The steel will not absorb extra carbon unless it is maintained at critical temperature for a given time(soaking). Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted January 27, 2018 Share Posted January 27, 2018 And the high alloy steels (Like D2) may require a substantial soak time at very high temperatures to put all carbon from all the different carbides into solution. Why these steels *REQUIRE* special heat treating and not "blacksmith methods" (why pay extra for the special alloy and then throw away the stuff that makes it special?) Quote Link to comment Share on other sites More sharing options...
Tubalcain2 Posted January 27, 2018 Share Posted January 27, 2018 K, I think that makes sense. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted January 27, 2018 Share Posted January 27, 2018 Hot cutting stock down rather than hammering down is faster as well. Quote Link to comment Share on other sites More sharing options...
(M) Posted January 29, 2018 Author Share Posted January 29, 2018 How hot is too hot for 5160? Doesnt hot cutting just cut across the grain and remove the strength benefits of forged knives? Or am i way off on that Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted January 29, 2018 Share Posted January 29, 2018 If you have a 3" wide leaf spring and want to make a 1.5" wide knife from it you are more likely to cause problems hammering it down to close to size than to increase the strength. Remember every heat you get decarburization and scale losses, (the grain size is probably being dealt with in the hammering and temperature cycling.) And in general for leaf springs you would be cutting along the grain and only be cutting across at the ends---where you would be cutting anyway! Too hot is where you start degrading the alloy or burning it up. Quote Link to comment Share on other sites More sharing options...
Joël Mercier Posted January 29, 2018 Share Posted January 29, 2018 2 hours ago, (M) said: How hot is too hot for 5160? Doesnt hot cutting just cut across the grain and remove the strength benefits of forged knives? Or am i way off on that The grain is at a microscopic level and has no sense or direction. Hammering hot steel breaks the grain and that is a good thing because forging heat increases the grain size. You want the grain as small as possible (to some extent, extremely small grain can be bad, though it's not achievable without repeated normalizing and quenching cycles.) Quote Link to comment Share on other sites More sharing options...
(M) Posted January 30, 2018 Author Share Posted January 30, 2018 Wow. What is the grain then? I thought it ran like the grains of wood laterally. Shows how much i know Quote Link to comment Share on other sites More sharing options...
Joël Mercier Posted January 30, 2018 Share Posted January 30, 2018 Have a read http://www.gowelding.com/met/carbon.htm Quote Link to comment Share on other sites More sharing options...
(M) Posted January 30, 2018 Author Share Posted January 30, 2018 Getting a better understanding i think. This is from greenbayforge.com Forgings have grain oriented to shape for greater strength. Machined bar and plate may be more susceptible to fatigue and stress corrosion because machining cuts material grain pattern. In most cases, forging yields a grain structure oriented to the part shape, resulting in optimum strength, ductility and resistance to impact and fatigue. Quote Link to comment Share on other sites More sharing options...
Joël Mercier Posted January 30, 2018 Share Posted January 30, 2018 This may be true for unhardened steel. It does not apply here. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted January 30, 2018 Share Posted January 30, 2018 Note too that forging by someone less skilled can also decrease strength due to issues they introduce. Quote Link to comment Share on other sites More sharing options...
(M) Posted January 30, 2018 Author Share Posted January 30, 2018 So what is the benefit to forging blades vs stock removal? I was also reading elsewhere in this forum that high carbon steels should be kept almost at a red black heat. How will i know if the alloy is degrading? Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted January 30, 2018 Share Posted January 30, 2018 read the melt sheets as to forging and welding temps Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.