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.
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.