4g20 Posted June 20, 2023 Share Posted June 20, 2023 I put four knives through two normalization cycles before hardening and once they came out I went to try and break it as a test for the others. When I started to bend it, it bent clean over 90 degrees and I was able to move it back and forth across the vice 5 times before it broke. It seemed to have a thin brittle shell but a very soft inside. Felt like I was moving hot steel instead of hardened. Quote Link to comment Share on other sites More sharing options...
4g20 Posted June 20, 2023 Author Share Posted June 20, 2023 I put a knife through two normalization cycles before hardening and after I quenched and let it cool I went to test my process by breaking it and seeing how it broke. When I put it in my vice, I could bend it clean over. I was able to move it back and forth five times before it broke. It felt like it had a thin brittle outer coat but the inside behaved as if it were red hot. Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted June 20, 2023 Share Posted June 20, 2023 Welcome from the Ozark mountains. Need more information, like what was your quenchant, what steel were you using, did you bring the steel to critical temperature non magnetic before quenching? Sounds to me like your steel wasn't hardenable. I can't control the wind, all I can do is adjust my sails. ~ Semper Paratus Quote Link to comment Share on other sites More sharing options...
velegski Posted June 21, 2023 Share Posted June 21, 2023 What did grain look like when you broke it. If it mystery steel did you do any tests prior to forging. Quote Link to comment Share on other sites More sharing options...
4g20 Posted June 21, 2023 Author Share Posted June 21, 2023 My knives after quenching are soft in the middle with a very thin skin that resembles scale. Two normalization cycles were done before quenching and I quenched in motor oil Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted June 21, 2023 Share Posted June 21, 2023 You still haven't told us type of steel or how hot you got it prior to quenching. If you are using mild steel it will never harden. I can't control the wind, all I can do is adjust my sails. ~ Semper Paratus Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 21, 2023 Share Posted June 21, 2023 4g20: If you want help YOU have to do your part and tell us what we need to know. If you don't there's nothing we can do for you. We'd like to, it's what many of are here for but you have to ask good questions, not vague word soup. An example of the kind of question you're asking is, 'My car won't run, I checked the air in the tires and the ash tray is empty. What's wrong?" You've been asked two times for the information we NEED to help you and you've repeated your original question with some minor change twice. If you don't know what kind of steal SAY SO. We can tell you how to evaluate it to tell if it CAN be used for blades. Make us guess and somebody among the 50,000 members here will take a guess for you. Want to keep guessing or want expert help? Your call. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
George N. M. Posted June 21, 2023 Share Posted June 21, 2023 BTW, used motor oil is a somewhat dangerous medium for quenching because it is contaminated with various heavy metals and the smoke that comes off when quenching is toxic. Plain old cheap vegetable oil is a better medium. As others have said, we can't help you if we don't know what kind of steel you are using. If you don't know, tell us where you got it and we may be able to make an educated guess. It sounds like it may be low carbon steel, aka mild steel, which doesn't have enough carbon to harden. If you are using mystery steel, e.g. a piece of a spring, it is a good idea before starting to forge to take a small piece, heat it and quench it and then put it in the vise and break it off to make sure that it will harden and you can examine the grain structure on the broken edge. There are some weird steels out there that are hard to harden and heat treat in a home shop. If you had done that before forging and/or grinding your blades you might not be having the problems you are having now. If this is the case you have just paid tuition with your time and effort to learn a lesson which you will probably never repeat. Also, please put your general location in your profile so that we know where you are. This is a world wide forum and we don't know if you are in Zanzibar, Tasmania, or Nebraska. "By hammer and hand all arts do stand." Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted June 21, 2023 Share Posted June 21, 2023 Here is another thought. Instead of break testing the knives you have made, if you have some of the same steel they are made out of bring it to my shop and we will test it. Or if you put your location in your profile you may be surprised to find out several of our knife making members could visit your shop to trouble shoot the problem. I can't control the wind, all I can do is adjust my sails. ~ Semper Paratus Quote Link to comment Share on other sites More sharing options...
4g20 Posted June 21, 2023 Author Share Posted June 21, 2023 My apologies for the repeated messages, first time on here and I didn't think it took it the first few times. Had to keep rewriting the problem. I'm starting off with railroad spikes as I've seen many others use them for knives. I just moments ago tried to quench in something they call super quench. Every time I've tried to get the test knife right it came up soft. The super quench helped some but they still bent rather than breaking. And before I hardened I put them through two normalization cycles. I tested the temp on a magnet. I've been told it's a few shades past that so I shot for that. Once again, sorry for the repeats Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted June 21, 2023 Share Posted June 21, 2023 Read the heat treating posts that is pinned to this section., it explains why RR spikes wont harden, I am too lazy to re type all that again here Quote Link to comment Share on other sites More sharing options...
George N. M. Posted June 22, 2023 Share Posted June 22, 2023 Yup, the problem is your steel. Railroad spikes are low carbon steel and simply cannot get very hard. Super quench will help to harden them as much as they can be but that is about it. Your steel needs to have enough carbon that a file will skate off it and not bite when it is hard, but not tempered. RR spike knives can be kind of cool but the reality is that they will never hold an edge for very long. They are more of a novelty blade than one that will really work well for a decent length of time without resharpening. For example, I would expect to be able to field dress a deer without having to resharpen my hunting knife but I would expect that if I were tyo use a spike knife I would have to resharpen once or twice through the job. There are a few spikes, usually marked HC on the head, which are higher carbon (about .40 % or medium carbon) and used on curves and switches which will get harder but still nothing like 1080 or 1095 steel. Better luck next time. If you are going to use scrap steel for a blade use an old spring but experiment with hardening and tempering first. Also, used or broken car springs can be problematic because they have been through thousands of cycles of compression and release and may have lots of little microfractures in them which can create problems for you and the blade in the future. "By hammer and hand all arts do stand." Quote Link to comment Share on other sites More sharing options...
Latticino Posted June 22, 2023 Share Posted June 22, 2023 I have used Super Quench on "HC" rail spike knives and picked up a little bit of surface hardness. It is not very deep, and you certainly can't temper. You have to be pretty much to final crossection before you quench. Any surface grinding after that will get rid of that hard layer, so it really isn't of much use to make a high quality knife. Nice gimmick though, and those I've given blades to seem to appreciate them. I batoned a recent one into a random piece of 1/4" mild stock and cut into it a couple of hammer blows with relatively minor glinting on the edge. Quote Link to comment Share on other sites More sharing options...
Irondragon Forge ClayWorks Posted June 22, 2023 Share Posted June 22, 2023 Like already been said, your problem is the steel and to some degree the oil quench. like Latticino, I have made some pretty nice RR spike knives, however if you sell or give them away you must tell whoever gets them that the RR spike is not good knife steel and will need resharpening often. They do make good throwing leaf blade knives as the edges do not have to be sharp and it's easy to get a good balance point with them. Hopefully you will be able to pick up some good knife steel like 80CRV2, 1080, 1095, or 5160 and turn out some good knives. How about some pictures of the spke knives, we love pictures ya know. I can't control the wind, all I can do is adjust my sails. ~ Semper Paratus Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 22, 2023 Share Posted June 22, 2023 On a last note, beware of what you see online. There at least two guys claiming RR spikes make good knives with videos showing the process and tests. What they don't show is a skating file, Rockwell file test OR unedited video between a chop test and slicing a piece of paper. The person I'm thinking of now sells how to books, lessons and not surprisingly no spike knives. As a gag one of the bladesmiths here I believe forged a high end RR spike knife by first forging a RR spike from high carbon steel and then making a knife from it. There are lots of excellent projects for RR spikes, there's a section about them here and a couple few threads. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
George N. M. Posted June 22, 2023 Share Posted June 22, 2023 Jeremy, just in case you think we are a bunch of guys blowing smoke at you, I would say that the combined experience in blacksmithing and knife making of everyone who ha reponded to you adds up to a century or two. WE've been there and done that including mistakes much worse than believing You Tube videos that RR spikes will make good knives. BTW, it would be nice if you put your location in your profile. "By hammer and hand all arts do stand." Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted June 22, 2023 Share Posted June 22, 2023 the few RR spike blades that are good, at least have a high carbon edge steeled onto them Quote Link to comment Share on other sites More sharing options...
4g20 Posted June 22, 2023 Author Share Posted June 22, 2023 P Thank you to all of you that responded. Cant say I'm happy with the answer but it is what it is. To those asking where I am, I'm near Punxsutawney. You know, the groundhog town? That's the one. Quote Link to comment Share on other sites More sharing options...
Frosty Posted June 22, 2023 Share Posted June 22, 2023 Welcome aboard, glad to have you. I HOPE your name isn't Phil! That would be just tooo juicy a straight line for me to resist, I've be in trouble with the mods all the time! Welcome to the club, I used to be associated with a guy who made "high end" knives from RR spikes and claimed to test every one. One of the issues that caused us to stop being associates was my demonstrating that no matter what you did you couldn't harden a RR spike. I was sure surprised when I couldn't get a HC spike to harden and went to extremes trying. At least his RR spike line shifted to letter openers. We parted for different and worse reasons I'm not going to get into. Most smiths have been there, RR spike KSOs (Knife Shape Objects) are popular with the buying public they just aren't knives, saying they are is misrepresenting the product. That's a B A D thing. Do you forge other stuff? RR spikes are good for lots of things not blade related. Frosty The Lucky. 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.