Heat Treating Knives, Blades etc

At a flea market this morning, I picked up several pieces of a tool steel marked "Firth-Sterling Circle C." 6 of them are 1"x1"x7" and one is 3/4" x 3/4". My understanding is the previous owner was a gun smith. I'd like to try my hand at making a small hatchet and thinking some might be usable as a forge welded cutting edge, but before experimenting with an unfamiliar material, I'm wondering if anyone has had experience working with and heat treating this material? Looking for ideal quench medium/heat treating conditions and any other advice on it's practical uses.

Hello! I'm very new to the blacksmithing world. This site rocks and thank you for those whom have already helped me out! I just have a quick question about tempering a RR spike knife. Could someone be kind enough to explain to me the property technique? Thanks so much!

Hopefully I am on the right place. I just was grinding my blade and notice that the spine warped a bit and was wondering if I can still put the blade back in the forge to fix some issues.

Hi folks. I wondered if anyone on here has tried a differential heat treat with 1095, and if so, what was your process? I forged a small skinner (8.5” OAL, 3” blade, 1/8” thick) from 1095. I’ve worked with 1095 many times and the HT can be tricky. Well, tricky when compared to 1084. Suffice it to say that I understand the (correct) standard HT process for 1095. With this current blade, I have file work along the spine, and while I could use whiteout and do a standard HT, the thought of doing it differentially came to mind, thus eliminating any scale on the spine. I also wouldn’t mind having only the edge hardened for this particular blade. Th…

First post, newbie on here. I'm an old dude sneaking up on 78, and I've done a few "finish it yourself" and stock removal knives in the past (some depicted below), but I want to get much better at it and eventually get into simple forging. I needed a better small tank for edge-quenching, so I looked hard online for a low cost off-the-shelf "tank", but everything I saw was either too wide, too deep, too short, or too wimpy. The closest I found was heavy duty commercial steel baking pans intended for making big restaurant-size bread loaves, but they were rather thin metal, and were non-stick coated, which I didn't particularly want. To get exactly what you want, someti…

So I'm new to blacksmithing/blade smithing and had a question. What do people use a kiln for. I understand quenching a knife and such but i'm unsure what to do with a kiln. I found a Evenheat kiln at a very low discount and wanted to know if I need it and what to use it for, how to use it.

Hey. I'm a new bladesmith (with a couple of years experience of traditional blacksmithing) and I've made a couple of knives out of O2 steel. The first one turned out great, but the second one had cracks all over the edge and spine. I've done a little bit of research and people say: the edge hardens first, so when the thicker spine hardens the edge can't flex => cracks. What I think caused it: I had problems normalizing it before hardening. The oil (canola oil) was probably not hot enough. I used a coke forge and struggled to reach an even temperature. Read a bit online and found out O2 isn't for inexperienced bladesmiths. I didn't know th…

I am making a knife for a customer whom I know will probably use the knife for food. I am using spring steel from a leaf spring and I want to know if I should use a certain oil, water, or brine. What would work best for my situation and how is the best way to do it?

I am making a series of knives using 1095, 1084 and 5160. Which blades would, or should, have the best edge retention. Please assume the blades all have the same edge geometry, and I am using the same hardening and tempering for all. The shop is in the style of around the year 1850. No electricity. To be specific, after normalizing I heat to non magnetic and let the work soak for a few minutes and then quench in canola oil . After hardening I take the work home and, within 3 or 4 hours, temper it to around 400 to 425 degrees Fahrenheit in my kitchen oven. I'm using separate a type K thermocouple to indicate the temperature because the oven controls don…

Has anyone sent an Elmax blank out for heat treat? Where did you send it? I contacted my go-to company for my 440c blanks, and the only premium steels they will do are s90v and s35vn.. Another company quoted me an astronomical price (hundreds..). I'm just looking for suggestions, and any experience shared is greatly appreciated.

Hello everyone, Ive been fooling around with some mild steel scraps I had lying around. Been trying to make steel out of them, by case hardening I believe its called. Well, Im not really sure, if its true hardened, could it still be called case hardening?? Anyways, it turned out successful so far, for my need of making a few parts for my percussion lock project, dont know the exact terminology... I reached the point where I need to make the big spring for my lock. So Ive been thinking, since my angle grinder is toast at the moment, and it would be a pain to saw through an old truck leaf spring by hand, could I make a spring by case hardening mild steel? …

I’ve been building my first larger blade (at least the first one I actually intend to complete) and I’ve just finished my first heat treat outside of punches and chisels in over a decade. This is 5160 from a new coil spring, forged in bevels and done entirely by hand. I don’t have a grinder that is up to the task, so I’m doing it the hard way. Any advise is appreciated. I was attempting to reach a blue spine with a straw to brown along the edge, I did better than I expected using a heated bar to cook the spine. I also attempted to submerge the edge and heat the spine with a torch... I need a new map-gas torch now. Thing was clogged up and didn’t work well at all. My …

Harbor Freight's Machete is made of "High Carbon Stainless Steel," I'd guess it's 7Cr17MoV, but I'm really not sure, since it's cheap and chinese. This is all guessing, and Step 5 would be started within 1 hour of step 2. But here's my off-the-wall idea: 1. Cut and Grind smaller knives from Harbor Freight machete made of "High Carbon Stainless Steel." Not sure how to anneal this. 2. Heat until non-magnetic. 3. Air Quench to room temp. (I read 1 post that said it was an air quenched metal, but I'd prefer to oil Quench.) 4. Place between Dry Ice Blocks to cryo treat to -109 F. (I've no idea if this will help) 5. Temper at 335 F for 4 hours …

Hi all, Made a blade from 125sc steel. Quenched in canola oil and tempered (twice) at 200c-220c (390f-430f). The problem - as I sharpen the blade, it chipps. Just from sharpening. It happens with fine whetstones, using an angle guide (10deg). Along all the blade. Note: before the hardening heating (with 5 minuts soak), I made several cycles of heat to orange and cool to black. This was suggested to me to achieve a black finish ("curo uchi"). could this cycling be the reason? I have not fixes handle yet, so I can re-temper, if there is a point. Would like your thoughts on that as well. 125sc is a pure high carbon (1.25%) steel with significant manganese content. T…

Ok, first off I’m a rookie so I could very well be doing something dumb. I have a blade that was forged from a piece of stock 1095 bar that I purchased. It’s been ground to shape but is still about 1/8 inch all over. I’m trying to heat treat it but when I quench in heated canola oil the left side of the blade is hardened but the right side digs the file. I’m stumped. I may have been placing the steel into the forge mostly on the same side. Could that be it? Any suggestions?

Brand new here, but I thought I might jump into it. I have some annealed 1/8" 52100 flats that I was hoping to use for a pair of pruning shears for my foreman at work. And yes, I'm familiar with how 52100 forges. I've made a few knives from it. It's just that I've never really spring-tempered anything before (as shown in the design). As far as equipment, I have a break drum coal forge, a few punches, wolf-jaw tongs, a straight peen hammer, some hot cut chisels, a rail anvil, and a low speed bench grinder with a sanding attachment. With what I have, how do you think I should best go about drawing it back? Should I use a different steel in regards to the spri…

I've been using canola oil for years now. I've not had many problems except for recently. I have been trying to get a big bowie knife quenched. I forged it out of leaf spring. It would not harden. At least with a file check. The file seemed to dig in every time. I tried 3 or 4 times. Finally I tried water. The file seemed to dig even still but it warped my blade. I tried to straighten it and it broke. The broken ends were very crystallized. I guess it hardened. But why didn't the file skate off? Any help is appreciated. Thanks, Chris

Hello. I have a small propane forge, and so far I've been working only with 1084, doing all of my HT using magnet and waiting for about a minute after non-magnetic before quenching. I've gotten pretty good results, but I want to become more scientific about it. So I bought a piece of black iron pipe and a thermal probe to be able to control the temperature better. Most of the sources I looked at say that I have to bring the steel to about 1500 and soak it for some time (this is where they start differing, suggesting times between 2 and 10 minutes). My understanding is that if the temperature remains around 1500, the actual time of soak is not that important becau…

I have been reading the stickies and watching youtube videos, and the result is that I am confused and have a headache. My normal method would be to make a bunch of test pieces and experiment for a few months to come up with a process, but thought it could not hurt to ask here instead. What I want to do is heat treat the tanto I am making to create and maximize a hamon. But I want to do the process in my kiln, using numbers instead of expert intuitive blacksmithing skills which I do not have yet. What I have is a piece of mostly 1080 damascus , about 5mm thick at the thickest point, and I left about 1mm flat where the edge will be. I have satanite to use for b…

I got a new blade for Christmas (Hibben IV). Made of 1090. Was going to sharpen it but the middle of the blade is to hard. I think it has a bad heat treat. Can I reheat treat a blade or will this just make it worse. If I can. What should i do. Thanks

Hello everyone, Its been very cold for the past month or so, and I was forced out of my workshop, probably all the way till spring I havent made a knife or some other edged tools in a while, mostly because of the weather, but also because Im getting something wrong during the HT process, my guess being the tempering stage. I have to point out that Im using mystery steels for my projects, mostly leaf springs and old files. So I know the steel is more than adequate for what Im aiming for, but I fail somewhere along the way. Im also using mostly hand tools, with the exception of one angle grinder, and one bench grinder... I will now explain m…

I'm just making my first differentially hardened knife and I have 0 idea if it needs to be tempered can someone tell if it does or not and if yes then how long and how hot

HI, I am completely new to working with metal but am a pretty experienced woodworker. That being said im not an idiot but im also not sure on what I am doing most of the time. My biggest issue is when i make a knife, with material removal not forging, I heat the steel to a non magnetic state, pull it out and brush it and then put back in for a few mins and then pull out to normalize. I do this 3 times and on the final stage I dip in warm canola oil. When I pull it out of the oil I noticed large black spots everywhere and when I take it to the grinder I realized that the divots went so deep into the steel that the knife was ruined. It looked like it had rusted for 30 years…

My local industrial surplus place has an old forced convection lab oven (for $35) that goes up to 280C/536F. The interior volume is 13.5"w x 11.5"d x 11"h. As a hobbyist, this strikes me as a good size for tempering tools (including hammers) and small to medium-size knives. The temperature range seems a bit low for all the tempering I might want to attempt, but might this be a worthwhile addition to the shop? Or should I just stick with my five buck toaster over?

I"m forging a blade with high carbon (pure carbon) core and wrough iron clad. Because of the WI, I have to work at very high temperature, which is bad for HC. As far as I know, it creates large grains. Is there a way to reduce the grain size?