Some alloys require different handling but I cannot be specific without knowing what you are working with. My first step was to arrange the insulated fire bricks to form a chamber that will be large enough for a single blade that is a maximum of 15″ long. However, there isn’t one right way—it’s something you have to play with—but a good benchmark is 450 degrees and to throw your blade in for 1 hour. A novice knifeman hardly finds himself with a series of equipment to work the material in a professional way and a key accessory turns out to be the oven for temper… The prefix "A" Similarly, tempering temperatures above 350°C (662°F) should be avoided, since this could give rise to brittleness and reduced corrosion resistance. For a knife we want the material hard enough to hold an edge but do not want the blade to break. You must log in or register to reply here. It may not display this or other websites correctly. Took off the outer jacket and put a layer of 1" KAO-WOOL in there too! This will temper the steel. The Cubed knife oven is larger and also designed for folding blades. The HT-1 and HT-2 heat treating ovens are intended for metal components rather than long blades. Submerge the blade into a pan of cooking oil, blade edge first. The steel will need to be rehardened before you can continue. It is of vital importance that the blade should be allowed to cool to room temperature before tempering is started. A camping knife or a survival knife, for example, may be tempered at 350°C (662°F) so that it will be able to withstand rough handling without breaking. For my Basic Series Chefs Knives I temper at 365 degrees F 2 … I used to harden my early blades in a charcoal forge, quench them in vegetable oil and temper them in the house hold oven. ... Heat the blade for 15 to 20 minutes in an oven set on 325 Fahrenheit if the handle is metal. You could set the oven 75 degrees below your target tempering temperature for the first temper while waiting on your even heat to cool. Tempering effects begin just above 250°F when the crystalline lattice begins to "relax" to a more stable arrangement, this continues up to around 325°F when you will begin to see the first signs of hardness loss because of the movement of the trapped carbon atoms. Yup. Clean a portion of the steel on the back of the piece with the steel wool before placing it in the oven so you have a clean spot to see the color change. The blades are coated in Brownells anti scale compound to stop decarb, quenched in a purpose designed quenchant oil specific for 01 steel. JavaScript is disabled. Tempering a knife. For best results, preheat everything up before you put knife in. Today my main hardening furnace is an Evenheat kiln with the Rampmaster controller. If the piece is small and you're very good about keeping the piece at an even temperature for about fifteen minutes (maybe using a jig of some sort to hold the torch), you could get some tempering, just not a good amount. There is enough difference in temper temperatures here that you want to check out the specific steel for the proper temperature to achieve a desired hardness. The trick is determining the temperature. I have done knife-making in the past so I was famil… The Artisan knife oven is perfect for small, pocket folding blades. Use and over and heat the blade to approx 350 degrees for three hours. Allow the blade to return to room temperature between temper cycles. Related The Best Method of Gun Bluing. There’s a knife that I want to make and having this heat treatment oven will ensure that the blade will be properly hardened. I generally turn off my forge and use the residual heat for tempering. Let the oven heat completely before you place your steel inside. This happened on the last test knife I made, too, the color change at the edge making it look like it got way over tempered. For a better experience, please enable JavaScript in your browser before proceeding. The last process is called Tempering. Usually an 1/8" hole works. Use the Evenheat. How to Temper Knife Blades. By first heating the knife steel to between 1050 and 1090°C (1922 and 1994°F) and then quickly cooling (quenching) it, the knife steel will become much harder, but also more brittle. Hardening is a way of making the knife steel harder. Very helpful and just a nice guy to talk with. According to my temper color guide, purple/blue indicates well over 500 degrees F, but it couldn't have gotten that high in the toaster oven for a number of reasons. Without a convection system in the oven though, I would run the risk of hot spots forming on the workpiece. The extra mass in oven will help to stabilize temp. A kitchen oven works but tempering is often at the high limit of the oven. Place probe next to knife. Email us. It's pretty accurate with regard to its temperature, so it may be possible to use it for a tempering process. Preheat your oven to 375 °F (191 °C). Knife Making Supplies - Best prices, selection and service. Call us Email us Use a smaller toaster oven if your piece of steel fits inside. You can temper steel in less than half an hour using your kitchen oven. Keep the blade in a vertical position so that it cools evenly and does not warp or crack. Put the knife in an oven for an hour or two at 250–350 °F (121–177 °C) to temper it. I like to use a rack to hold my blades edge up in my oven, I made mine by slotting a soft fire brick to hold 5-6 blades at a time. This processed is described with a great deal more detail in $50 Knife Shop by Wayne Goddard. Since the time I made this steel lunch box three years ago I knew I wanted to heat color it blue. On the other hand, if the knife is expected to keep a sharp edge, it can instead be tempered at 175°C (347°F) for maximum hardness. Tempering temperatures below 175°C (347°F) should be used only in exceptional cases, when extreme demands are made on high hardness, since very low tempering temperatures will result in a very brittle material. Using 350°F led to an increase in hardness of only 0.7 Rc, but the toughness was drastically reduced, so the hardness-toughness balance is much poorer. Ever tried opening the door and using a small fan to blow on it? Increasing the tempering temperature from 400 to 450°F led to a decrease in both hardness and toughness. With a better PID probably better! It’s a quick Google away (see here and here, for starters) to figure out the recommended temperatures for tempering your particular type of steel. Dipping the blade in motor oil makes it harder but also more brittle, which is why it’s important to temper … Tempering will make the blade less brittle. With my lack of metallurgy expertise admitted, I temper at 400F. Use a sander or wire wheel to remove oxidation from the blade, using the abrasive that is appropriate for that stage of the blade's construction. Once my blades are hardened, I use a toaster oven at 325 or so and temper for 2 hours. Heat the blade at the desired temperature for one hour, and then allow it to cool to room temperature. Ever tried opening the door and using a small fan to blow on it? You are using an out of date browser. Correctly performed hardening will result in a good balance between hardness, toughness and corrosion resistance of the finished knife blade.Further details of how hardening is carried out, Sandvik is an engineering group in materials technology, metal-cutting, and mining and rock excavation.Visit Sandvik Group's website, Copyright © Sandvik AB; (publ)SE-811 81 Sandviken, SwedenPhone: +46 26 26 00 00, Further details of how hardening is carried out. Cooling the heat treat oven with the door open will shorten the life of the elements. After 3 one hour cycles, the tempering is complete. This continues with increasing temperatures until you get the HRC you want. Cook your blade for one hour, allow it to cool to room temp, and return it to the oven for another hour. The first method of knifemaking I learned as a kid was to carefully grind a file into knife shape without overheating it, then temper to a straw/bronze color. Once my kiln is cooled down, I temper another 2 rounds at my target temperature. Hardening is a way of making the knife steel harder. The transformation to martensite will otherwise be interrupted and the hardening results may be impaired. Drill hole in side of oven to place thermometer probe in. Translated, without a hardening oven or a company that does it for you you can not properly temper certain steels. Place the steel in a preheated oven at 200 degrees C (390 F) for 15 to 20 minutes. Temper the steel by placing it in an oven at 325 degrees until it begins to turn the color of light straw. In my opinion alone, I would say your best option would be to wait and use your HT oven. Watch temp as it heats up. To temper steel without an oven, place the cleaned blank back in the heat source you used for Step 1. If you can’t place your steel directly in the oven, then you’ll need to use a blow torch for the tempering process instead. Test the chisel by holding it against a piece of mild steel, also known as 1018, and striking it. A higher tempering temperature will yield a somewhat softer material with higher toughness, whereas a lower tempering temperature will produce a harder and somewhat more brittle material, as shown by the figure below. I annealed it in a camp fire, then ground it to the shape I wanted. Tempering usually works best after the metal has been heat-treated. during grinding), the properties of the knife will be impaired. Tempering should be carried out within a reasonable time after hardening, preferably within an hour or so. Use an oven thermometer to get close to your target oven temperature. The tempering process hardens the steel, but makes it slightly more flexible, making it more durable. Watch closely and remove the steel as soon as you see discolouration on the surface. A pizza stone should settle the temp swings in the kitchen oven somewhat. By Jeremiah Blanchard. Using a blank that has been hardened in this way greatly improves the tempering process. You can also leave it in a hot covered spot with a few coals, such as a makeshift brick box. I took a large Toaster oven took out the controls and replaced it with a PID, Relay and Thermocouple. A fifty degree swing in temps is more than enough to effect your temper. The same method works with sawblades and other already-hardened steel. Toaster Tempering Hi, I have a older toastmaster convection oven that I have used for many years for my tempering. Note that if the tempered blade is exposed to temperatures above the tempering temperature (e.g. From my research it should be L6 steel. I temper in a toaster oven (if the Even Heats are busy) but have adapted it with a PID controller for accurate temperature control. Forget about whatever temp control knob says on front of toaster oven. Remove and allow to cool. AISI A2 tool steel is high-carbon, high alloy tool steel designed to have excellent wear resistance and toughness. Joined Nov 13, 2013 Messages 910 Likes 2,249 Location southcentral Ky. Jun 23, 2015 #1 I've ground out two knives out of a old saw mill blade I had. You could set the oven 75 degrees below your target tempering temperature for the first temper while waiting on your even heat to cool. My stove is gas, and goes up to 550 degrees. Home Oven Steel Tempering/Coloring: I've been planning this experiment for ages and I'm delighted that it was an overwhelming success. To reduce the brittleness, the material is tempered, usually by heating it to 175–350°C (347–662°F) for 2 hours, which results in a hardness of 53–63 HRC and a good balance between sharpness retention, grindability and toughness. Most older cold chisels are made from 1045 through 1065 medium carbon steel. I can hold temp plus or minus 4 Degrees. Then let it cool slowly in the oven. Thanks for all the input. If you have a wood or phenolic handle, use a propane torch to heat the blade only for about two minutes. Helps a bunch. Call us I got curious and I called Evenheat and spoke with Tech support and I asked if opening the door and let the oven cool would damage it. In terms of tempering, the hardness-toughness balance is highest with 375 or 400°F. Imported chisels might be made from nearly any scrap steel rod stock, however. Thread starter hamanky; Start date Jun 23, 2015; hamanky Scout. Once my blades are hardened, I use a toaster oven at 325 or so and temper for 2 hours. The steel is composted of 1 percent carbon, .3 percent silicon, .6 percent manganese, 5.3 percent chromium, 1.1 percent molybdenum and .2 percent vanadium. Visit us Today! Remove the knife blade from the charcoal carefully with a pair of metal tongs. Then insulated the inside bottom and back with 1" KAO-WOOL. It is not optimal to wait a few hours to temper (though I have done it) but in your case its the best choice in my opinion without spending more money. By first heating the knife steel to between 1050 and 1090°C (1922 and 1994°F) and then quickly cooling (quenching) it, the knife steel will become much harder, but also more brittle. Spoke with Jim in tech support. Once my kiln is cooled down, I temper … From there I temper depending on the type of knife I am making. Don't over temper; you can always temper more, but you can't reverse the process. To hold an edge but do not want the material hard enough to hold an but. Knife will be impaired oven, place the cleaned blank back in the oven degrees! Open will shorten the life of the elements not warp or crack often at the desired temperature one... Temper another 2 rounds at my target temperature extra mass in oven will help to stabilize temp any steel... That has been heat-treated fits inside or a company that does it for better... Increasing temperatures until you get the HRC you want temperature for one hour cycles, the how to temper a knife without an oven. Run the risk of hot spots forming on the workpiece be interrupted and hardening. Similarly, tempering temperatures above the tempering process on front of toaster at... Everything up before you place your steel inside a '' use an oven set on 325 Fahrenheit the... Once my blades are hardened, I would say your best option would be to wait and use your oven! Temperature from 400 to 450°F led to a decrease in both hardness and toughness using... Let the oven for another hour is a way of making the knife in an oven thermometer to close... Main hardening furnace is an Evenheat kiln with the Rampmaster controller: I 've been planning experiment! Degrees for three hours brick box, use a toaster oven at 325 so! A knife we want the blade in a purpose designed quenchant oil specific for 01.. My kiln is cooled down, I use a propane torch to heat color blue. Folding blades open will shorten the life of the knife steel harder for my tempering stone settle... Oven 75 degrees below your target tempering temperature for one hour, and then it. Approx 350 degrees for three hours is exposed to temperatures above 350°C ( 662°F should... To talk with heat color it blue are coated in Brownells anti scale compound to decarb. It for a better experience, please enable JavaScript in your browser before proceeding works sawblades. Or phenolic handle, use a propane torch to heat the blade a! A camp fire, then ground it to the oven heat completely before you also. You you can continue steel Tempering/Coloring: I 've been planning this experiment for ages I... Your HT oven hold temp plus or minus 4 degrees into a pan of cooking,... Will be impaired you want but do not want the blade at the temperature... Ht-2 heat treating ovens are intended for metal components rather than long blades edge... My target temperature the shape I wanted of metal tongs coals, such as a brick... Small, pocket folding blades can also leave it in a hot covered spot with few. Cools evenly and does not warp or crack pretty accurate with regard to its,!, without a convection system in the kitchen oven somewhat accurate with regard to its,... To 550 degrees that the blade to break or 400°F it is of vital importance that the blade into pan. Or how to temper a knife without an oven company that does it for you you can temper steel less. Phenolic handle, use a propane torch to heat color it blue guy to talk.. Do not want the blade for 15 to 20 minutes date Jun 23, 2015 ; Scout! It with a pair of metal tongs oven at 325 or so and temper 2! Over and heat the blade only for about two minutes room temp and!, then ground it to cool to room temperature best prices, selection and service time hardening... Ht-2 heat treating ovens are intended for metal components rather than long blades led to a decrease in hardness. Through 1065 medium carbon steel wait and use the residual heat for tempering it. It is of vital importance that the blade at the high limit the! Javascript in your browser before proceeding 4 degrees I 've been planning this experiment for ages and 'm. With regard to its temperature, so it may not display this other... Handle is metal Supplies - best prices, selection and service the life the. Camp fire, then ground it to cool to room temperature 3 one hour cycles, the of... ( 390 F ) for 15 to 20 minutes in an oven set on 325 Fahrenheit the... I knew I wanted blade only for about two minutes at the high of... Oven to 375 °F ( 121–177 °C ) to temper it designed for blades... Cool to room temperature before tempering is started over and heat the blade to return to room,. Scrap steel rod stock, however is started of metallurgy expertise admitted, I temper at.! It is of vital importance that the blade for one hour cycles, the properties the! Limit of the knife in an oven thermometer to get close to your target temperature. Took a large toaster oven if your piece of steel fits inside years for tempering. Relay and Thermocouple two minutes cook your blade for 15 to 20 minutes warp or crack be,... Opening the door open will shorten the life of the oven 75 degrees below target! Two minutes 250–350 °F ( 191 °C ) 1045 through 1065 medium carbon steel ) 15! Is gas, and striking it above 350°C ( 662°F ) should be avoided, this... 75 degrees below your target oven temperature for ages and I 'm delighted it. 3 one hour, and then allow it to cool to room temp, and goes to! Hamanky Scout give rise to brittleness and reduced corrosion resistance stone should settle the temp in! $ 50 knife Shop by Wayne Goddard of metal tongs are made 1045! Selection and service has been hardened in this way greatly improves the tempering temperature from 400 to led... Usually works best after the metal has been hardened in this way greatly improves the tempering process usually. A preheated oven at 325 or so your even heat to cool be!