NCHammer Posted December 31, 2018 Share Posted December 31, 2018 I bought some 5/8 in REbar at Home Depot I tried to make a hardy tool and it came out ok and I quenched it in water, then tempered it at 400 degrees Fahrenheit for 4 hours. I guess there were some cracks but it definitely broke like hardened steel. Does this mean it can be used to make a knife? Link to comment Share on other sites More sharing options...
Daswulf Posted December 31, 2018 Share Posted December 31, 2018 Only if you feel like risking and probably wasting your time. Get a proper steel for knives and at least with coil or leaf spring you have a better chance of ending up with something usable. Link to comment Share on other sites More sharing options...
dickb Posted January 1, 2019 Share Posted January 1, 2019 Ditto . Rebar is wonderful stuff for embedding in concrete. Waste of time and effort using it in a blacksmith shop. Link to comment Share on other sites More sharing options...
ThomasPowers Posted January 1, 2019 Share Posted January 1, 2019 Let me rephrase this: "I tried to make something easy with rebar and had a number of flaws in it; Can I make something difficult from it?" Does that answer the question? Link to comment Share on other sites More sharing options...
sfeile Posted January 1, 2019 Share Posted January 1, 2019 Rebar is generally pot metal. It is recycled whatever steel. It may contain old car rims, pieces of structural steel, old axle shafts, whatever junk they can salvage. You may encounter a mildly harden-able spot or two, but not likely the whole bar will be. There are some higher grades of rebar with a little more consistency, but you won't find those at home depot and still won't be a good consistency or even known material. Just that they meet a higher strength (not hardness) requirement. Unless it's specified as a weldable rebar, it doesn't even like to take a weld without cracking or chunks breaking off. As Thomas said, you already had cracks in it with a simple squaring, do you really want to try and make a knife from that? 5160 or 1095 are good easy to quench in a home shop steels that can be had for the same or only slightly more than you paid for the rebar at someplace like Jantz supply. Even leaf spring is a better 5160-ish material that will yield better results than rebar. It's not guaranteed to be 5160, but usually has similar properties and can be used for practice, tools, and gifts. Just be careful of stress fractures and avoid broken pieces. Link to comment Share on other sites More sharing options...
Daswulf Posted January 1, 2019 Share Posted January 1, 2019 Rebar can be used for things. Just Do Not think you can make acceptable knives or tools out of it. You can make bottle openers from it. Handles that you wont handle often or a firerake to get by till you make one out of something better, armatures for sculpture, all kinds of non essential stuff. But thats when it is free. Don't buy rebar to make much of anything. Buy good steel. Usually rebar is used because it is free or pretty much that. It is not desirable. If you purchase steel, get the correct steel for what you want to make. Purchasing rebar is purchasing steel to embed in concrete. Getting some free is why anyone mentions using it. There are way better steels to use per the job at hand. Link to comment Share on other sites More sharing options...
Jim L. Posted January 4, 2019 Share Posted January 4, 2019 Forging a cutting tool from rebar is a lot like forging one from a rail road spike. It can be done. It can be made sharp. Its cheap. Edge retention will be 3-6 out of 10. If you must use rebar, try to get scraps of the stuff used in bridges. Supposedly it has to meet higher standards because of failures. Just a thought. Link to comment Share on other sites More sharing options...
sfeile Posted January 4, 2019 Share Posted January 4, 2019 2 hours ago, Jim L. said: Supposedly it has to meet higher standards because of failures. It meets a higher yield strength, not a higher carbon content or harden-ability. A lot of bridge bars are a coated in an epoxy finish for corrosion resistance also, so you have that to deal with before you can even start to forge it. It is still made of recycled materials, so you still don't know what kind of steel you are getting. Free rebar can be used to make some things as Das said, but you can buy 1/2 inch structural round stock for around $16 per 20 feet at a supply house, and have better steel for general use. (24 feet of 1/2 inch rebar at home depot is $30.) Still not good knife material though. A rail spike isn't that good either. It doesn't have the carbon content needed to properly harden for a decent knife. I believe they are spec.'d to have no more than 0.30% carbon content in the HC rail spikes, and only 0.20% for standard spikes. They make a decent letter opener, but not really a quality hardened knife. Leaf spring or coil spring is generally a 5160ish material. Maybe not exactly, but similar. That averages around 0.56% to 0.64% carbon content. Much better and can still be had for free or very cheap generally if you are using recycled/scrap materials. 1095 steel is around 0.95% carbon content. If you are going to buy steel specifically for a knife, 1095 is easy to work with, fairly inexpensive, and easy to heat treat in a home shop. So while you can make a "knife" from rebar or rail spike, will it really be worth all of the time and effort you put into it? Link to comment Share on other sites More sharing options...
JHCC Posted January 4, 2019 Share Posted January 4, 2019 On 12/31/2018 at 8:54 PM, Daswulf said: Rebar can be used for things. Just Do Not think you can make acceptable knives or tools out of it. You can make bottle openers from it. Handles that you wont handle often or a firerake to get by till you make one out of something better, armatures for sculpture, all kinds of non essential stuff. But thats when it is free. Don't buy rebar to make much of anything. Buy good steel. Usually rebar is used because it is free or pretty much that. It is not desirable. If you purchase steel, get the correct steel for what you want to make. Purchasing rebar is purchasing steel to embed in concrete. Getting some free is why anyone mentions using it. There are way better steels to use per the job at hand. Every word of this. Link to comment Share on other sites More sharing options...
Jim L. Posted January 4, 2019 Share Posted January 4, 2019 (edited) @sfeile makes the point that I was trying to. The idea of the lower carbon contents is to, at least in the case of the RR spikes and poosibly the rebar is to make them more temperature tolerant. Desert loateted rail roads must endure temps ranging from the 30's at night to 90's/100's during the day. Metal fatigue can result with less maleable steels with higher carbon contents. Bent steel still has the potential for support where as broken won't. They are great for practice when free, but not so much when you have to pay for them. This is as I understand it and would gladly stand corrected Edited January 4, 2019 by Jim L. Incomplete thought Link to comment Share on other sites More sharing options...
ThomasPowers Posted January 4, 2019 Share Posted January 4, 2019 They went to the higher Carbon, edge of mild/Medium, spikes with the powered spike driving machines that required a bit more stiffness as they couldn't "adjust" while driving a spike in like a gandy dancer could. Link to comment Share on other sites More sharing options...
BIGGUNDOCTOR Posted January 4, 2019 Share Posted January 4, 2019 Rebar is the hot dog or chorizo of metals, you really don't know what is in it..... Link to comment Share on other sites More sharing options...
Binesman Posted January 18, 2019 Share Posted January 18, 2019 On 12/31/2018 at 5:58 PM, dickb said: Ditto . Rebar is wonderful stuff for embedding in concrete. Waste of time and effort using it in a blacksmith shop. not true it makes some great scrap for the kids to bang on. Link to comment Share on other sites More sharing options...
Jim L. Posted April 2, 2019 Share Posted April 2, 2019 Very true. Link to comment Share on other sites More sharing options...
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