hi all. I'm new to making knives and its now all I can think about, I'm sure you all know how that is.lol I have a few issues and questions, any help would be greatly appreciated as I'm doing everything that I researched to a tee with the tools I have.. 1--I have a gas forge I made and a high end toaster oven with a oven thermometer I purchased in it. first I heat my 3/16 0-1 steel up to critical temp and quench in transport used oil(switching to peanut oil as it will smell better) at 160F then after a quick cleaning and hand sanding straight to the oven at 400F twice for 2hrs each and my blade still snapped when I tried to do a slight flex text in a vise with wooden blocks to test the tempering I have now made a 1/8 0-1 blade of my own design and have done the same steps but tempered the blade three times at 425F I made this blade to test but have fallen in love and don't want to brake it haha anything I'm doing wrong with info given 2--I understand 0-1 is a harder steel but they should flex and not snap... should I try a better steel not saying its the steel and not me, just is there a better blade carbon steel to begin with 3-- how do the rest of you test you blades my millwright apprentice that wants me to make him one always tests his blade he has to the max and I know he will expect the tip to penetrate wood and pry a chunk up thanks in advance also cant get photos to work will try later
1) use Canola oil, its quenching speed is between #50 parks (6 second) and mineral oils (11 seconds). heat the oil to a temperature between 120 and 140F 2) The amount of flex is or lack of is related to tempering temperature 400F temper-very little flex, 800F temper - spring like flex. Best to aim for a hardness you or your users are happy with in the Rhc range of 58-61. I prefer a higher number and harder to sharpen but it will stay sharp longer. 3) Tempering charts below. at the 425 temper you used you are still above 60Rhc so no really bendy unless your blade profile was fillet knife like Tempering Temperature F Rockwell C 300 65 350 63 400 62.5 450 61 500 60 600 57 4) see Cashen Blades web site for a good heat treating routine for 01 http://www.cashenblades.com/steel/o1.html 5) buffalo precision technical sheet www.buffaloprecision.com/data_sheets/DSO1TSbpp.pdf Heat Treating Instructions Hardening Critical Temperature: Ac1: 1350°F (732°C) Ac3: 1400°F (760°C) Ar1: 1295°F (703°C) Ar3: 1240°F (671°C) Preheating: Heat at a rate not exceeding 400°F per hour (222°C per hour) to 1200-1300°F (649-704°C) and equalize. Austenitizing (High Heat): Heat slowly from the preheat to 1475-1500°F (802-816C) Soak for 30 minutes for the first inch (25.4 mm) of thickness, plus 15 minutes for each additional inch (25.4 mm). Quenching: Oil quench to a temperature no lower than 150-125°F (66-51°C). Note: O1 is somewhat prone to quench cracking, especially if there are significant changes in section thickness and sharp internal corners. The oil quenching should be performed so that the heat removal is as uniform as possible in all areas of the part being quenched. Be sure to remove the part from the oil before the temperature drops to ambient temperature. Hot oil at a temperature of 300 to 400°F (149-204°C) is recommended. Tempering: Temper immediately after quenching. Do not allow the part to cool below 125°F (51°C). The typical tempering range is 350 - 400°F (177 -204°C). Hold at temperature for 1 hour per inch (25.4 mm) of thickness, 2 hours minimum, then air cool to ambient temperature. Cryogenic Treatment: Refrigeration treatments should typically be performed after the temper, and must be followed by a second temper. for photos use imgur or similar site and copy past the forum link
As John pointed out in his post, you should soak O1 for a few minutes to get the most out of it. However, what you're doing should result in a good blade that will hold it's edge. You could try a simpler carbon steel like 1084 using your same method. You should be able to draw it back more easily to a softer, more flexible state. That said, you're making a knife, not a spring. As the maker, you have to decide what traits are important in your blades and to find a balance between edge holding and flexibility. There will always be people like your friend who mistakenly think they should be able to use any knife as a screw driver, can opener, chisel, or pry bar. Knifemakers have a name for those people: repeat customers -- because they'll always need a new knife.
Repeat customers have to admit that is much nicer than the term I use. There is now 1080 and 1084 on the market, mill run has finished and the steel is making its way through the system once again. In a pinch you can also use 80Crv2 which is an improved version of 1084 with the same heat treating schedule.
Wow guys thank you all so much that's a lot of great info. Yes my friend is crazy in my mind. I would never use a 4" hunting knife like that myself. Maybe a big survival knife but ya haha So to soak in a gas forge. Just turn the gas down a bit and run it back and forth not allowing it to over heat but giving it time to stay at critical?
In a forge you are best served to have a manifold to help stabilize the blades temperature and protect it from open flame. Big fancy sentence for stick it in a piece of pipe
Haha that awesome. So put knife into pipe and the flame heats up forge but dose not hit blade. Good stuff thanks.
the one that broke during a slight flex test. possible the jimping was also a bit ambitious for a beginner and my first attempt at a ffg on a blade
my forge. tank has an acetylene regulator on it for setting pressure as well ( hoses and manifold are now mounted off to the right away from heat haha )
For the one that broke and others you may want to flex test avoid having square notches anywhere in the bend area or even on the knife. Like the sharpening choil this should be rounded until all heat treating is done then if you want a square one fix up the corners afterwards. Square corners act as stress concentration points and due to the material coming to a very fine point (low mass) they will fail sooner than a rounded corner (larger mass)
that's actually fun cuz I had such a dummy move as I learned that in my machining course and my millwright courses, and before heat treat the choil on the one that broke was rounded with my air pen grinder and a end-mill just like the one that is tempered, but dummy me totally ignored the imping and that's where it failed first :\ , but I went I continued the stress test it was brittle still but I did my temper at 400 so the next one was stepped up a bit and I'm hoping this helps. also will the help you guys have given me and some more studying ive realized the steels I like, like 01, 80crv2, 154cpm, s30v all need special care of temp control during heat treatment in what seems to be kilns, so maybe ill have to send them out if that's the case... is this normal for ppl? might also try starting with 1084 like stated above. and for the jimping if I ever try them again I'm guessing a very small rat tail file or a dremel disk that's rounded off maybe? thanks John.
If you are using a forge for heat treating and do not have a dedicated furnace then stick with some straight forward steel like 1080, 1084, 80Crv2 and possibly 01 If you want the jimping nice and crisp which will look nice I would hit with 600 or 800 grit and chamfer the corners. At least that sounds reasonable. I have a furnace myself and have not heat treated a blade in a fire since 1989 and when I started knife making a couple years ago the furnace was ordered pretty quickly. I don't know where you are living but there may be a member with a furnace nearby and if not then Knifemaker.ca has a heat treating service. Also many larger cities have industrial sized heat treating companies that may be willing to take on smaller projects. https://www.knifemaker.ca/Heat-Treat-Service/
thanks I just emailed rob at knifemaker today about steel and just sent one about the serves, I'm near London Ontario, there's probably something around too but Robs prices seem good haha I cant find anything on forge heating 80crv2 online but the key seems to be in the normalizing and stress reliving before the heat treat but ya I'm gonna have to look into a furnace if this addiction I mean hobby grows for me haha I'm about to make a 2x72 grinder so that's first but one day lol
You need magic Google fingers or search original designation in this case AISI L2 or Designation by Standards DIN EN AISI 1.2235 80CrV2 L2 (sometimes) Chemical Composition (in weight %) C Si Mn Cr Mo Ni V W Others 0.80 0.33 0.40 0.55 - - 0.20 - - Description Low alloyed Cr-V cold working steel. Applications Circular saws for timber, saws for non ferrous, machine saws, measuring tools, tools for wood working axes, knives, punches, guide rods, twist drills, reamers, ejector pins, dentist's drills. Soft Annealing Heat to 710-850C, cool slowly in furnace. This will produce a maximum Brinell hardness of 220. Stress Relieving (Normalizing) Stress relieving to remove machining stresses should be carried out by heating to approx. 650C, holding for 1-2 hours at heat, followed by air cooling. This operation is performed to reduce distortion during heat treatment. Hardening Harden from a temperature of 810-840C, 780-810C followed by oil (up to diameter 15 mm) or water (for diameter higher then 15 mm) quenching Hardness after quenching is 64 HRC. Tempering Tempering temperature: See the data below. Tempering Temperature (C) vs. Hardness (HRC) 100C 200C 300C 400C 64 62 57 51 Forging Hot forming temperature: 1050-850C. Other standard Standard Specs AFNOR - 100C3* AFNOR - 55CNDV4 AISI - L2 CSN - 19419 CSN - 19421* CSN - 19422* DIN - 115CrV3* DIN - 80CrV2 DIN - 80CrV2* EN - 80CrV2 EN - 107CrV3* GOST - 9KHF* GOST - 11X GOST - 11KHF GOST - X1F GOST - 11XF GOST - KH1F GOST - 11KH JUS - C.4141* JUS - C.4844 PN - NW1 UNE - 120CrV UNI - 107CrV3KU* UNS - T61202 W-Nr - 1.2210* W-Nr - 1.2235*
a pdf from a supplier for heat treating http://www.bestar-steel.com/site_files/files/material_data/BE2235.pdf
