I decided to set myself a challenge and have a go at forging a blade I had not yet attempted the two layer deba knife. Half mild steel the other half in 80CrV2 sometimes known as 1080+ or 5160 on steroids. This is the construction of many single beveled knifes that you see when traditional Japanese bladesmiths forge tools. Importantly this construction only works for asymmetrical grinding because the hardenable steel should be on one side only. The major challenge this poses for the bladesmith is that when the steel hardens the martensite expands a little. So the high carbon portion of the blade warps with nothing to expand on the other half and push back against it. To guard against how dramatic the curve is proper normalization after forging should be adhered to. Another thing I believe the Japanese blade smiths might do is quench the blade on a bias… I noticed in some videos that instead of quenching vertically (i.e. blade edge directly down spine towards roof) they slide the steel into the quench soft cladding side down. I didn’t try this myself but if I have another go today I might. At any rate these measures will only minimise the warping at best. I waited until after hardening to grind the blade.
Heat treatment for 80CrV2 that I followed.
Forge to shape
Normalise at descending temperatures allowing to room temp in between 900, 850, 700. I soak at these temps for about 5 minutes when the steel is equalised. In the video you see my middle normalisation cycle.
Austenitise (harden) I chose to harden it from the lower end of the advised hardening range for 80CrV2, 840-880 degrees. I used a digital thermocouple reader for this as the lighting conditions vary in my shop. Colour is not a great gauge for temperature. I quenched into Houghtons G quench a medium speed steel. The added chromium and vanadium aid deep hardening in this steel so I feel no need to go for a fast quench and risk blowing the weld just yet.
I tempered this following the grinding at 190 degrees twice for 2 hours each allowing it to cool to room temperature between cycles. I will use hardness test files for a quick check of hardness. If I achieved maximum hardness in the quench the blade edge should be just above 60 HRC.
After grinding and etching I found that there was a small bit of delam near the heel of the blade which I will take out now the bade is tempered. In the next video I will show the final grinding etc. I want to hollow grind the back and see if by removing an amount of the 80CrV2 from the body the warp relieves a little before I go hitting the blade about too much.
New Blacksmithing courses available Newcastle AustraliaRead More
Very excited to now be offering a limited number of places for weekend knife making classes in the Newcastle area. Class has been designed for beginners to come in and learn the bladesmithing craft incorporating traditional blacksmith skills and modern tools. Knives will be crafted from a quality high carbon steel that can be sourced easily if bladesmithing is something you think you would like to continue. I aim to provide a class that allows students to go home with the right knowledge and skills to enjoy making their own cutlery at a home workshop. However anyone with a sense of adventure and desire to learn will find this a very enjoyable weekend.
Do you want to experience the satisfaction of forging a kitchen knife? Head to the Learning page and check out the dates available.
For my next installment in the beginners series I decided to do the fast and loose approach to heat treating 5160 & SUP9 (which are the same thing).
This method will be suitable for people who ALREADY have an Oxy/LP Oxy/Acetylene rig. This will work for smaller knives with the Bunnings brand Bernzomatic torches. It is far cheaper to buy the parts for a gas forge that will do a much better job of your heat treating than it ywould be to go out and buy a $400 cutting torch set and rent an Oxygen bottle. This is by no means a definitive guide to the heat treating of spring steel for knives... just a place to start.
Heat past non magnetic (Ideally 830 Celcius) and hold for 2-5minutes
Quench blade first into oil (conola, vegetable but not motor oil)
When cooled to room temperature grind surface back to expose bright steel
Test bright steel at edge, if hardened correctly it should be "glassy" a regular file should have a hard time marking it
Put in kitchen oven on 205 Degrees Celcius for 2 hours, then let cool outside of the oven to room temperature. Then repeat. Steel must be tempered twice.
This should result in a blade that has a degree of toughness and hardness suitable for use as a knife.
Steel = SUP9 x 6mm x 70mm x 1200mm
Tongs: Wayne Saunders Knife makers tongs
Thermocouple reader : (ignore the photo it is different)
Forging a San Mai Style Chef knife with a 52100 core and 15n20 jacket.Read More
This concludes the building of a custom Damascus clad San Mai blade for a customer, it will also be accompanied by a matching paring knife.
Damascus refers to the technique of forge welding multiple contrasting steels together
San Mai is a Japanese term for 3 layers. The damascus I created earlier is forge welded on the outside of 15n20 and 1095 forming the core. There is a link in my store if you would like to order your own.
The final billet is formed buy forge welding a high carbon core between two layers of nickel steel and the halved pattern welded portions. The layer count can be a maximum of 75 layers, but loss due to scaling will bring this down a little.
Day 2, now with 100% more moustache...
Using the new power hammer to begin a custom order, a carbon steel damascus kitchen knife.
Pictorial work through of the process I use to make a leather bushcraft sheath.Read More
Just trying something new with some left over pattern welded steel I had made
I decided as the first meal to commit to this blog it should be something that ties together iron working and food. Irn Bru rose to fame in Scotland and abroad from its roots in Falkirk as the preferred soft drink of steel workers there (as legend has it?). Now it outsells Coke and Pepsi in Scotland, and as I moved North on my travels I noticed less soft drink options and more Irn Bru. I'm Okay with that. So here's what I made last night, slow cooked Irn Bru beef.
What you need:
- Sharp Knife ;)
- 1.2 kg chuck steak
- 3 carrots
- 4 cloves of garlic
- 1 onion
- 2 tbs red wine vinegar
- 1 tbs Worcestershire sauce
- Some paprika
- 1/4 lemon
- Parsley to serve
- mash potatoes (Surely this needs no expansion)
- 1L Irn Bru ( I get mine from Coles its with the international food, annoyingly I could only get it as 330ml cans)
- 1/3 cup of sugar
I literally threw most of this into the slow cooker. Simple huh? Cut the carrots into large chunks and dice the onion, add the beef on top of them, crush the garlic and throw it in. add the vinegar, Worcestershire sauce, a pinch of paprika, pepper. Lastly add the Irn Bru over the top.
I set the Slow cooker to high for 8 hours and went of to do blacksmith stuff. That might not effect the outcome of the dish but you might like to consider it.
When the beef was tender I removed 3 cups or so of the broth, added it to a saucepan squeezed in the lemon and added the sugar. I heated it on the stove until the sauce had reduced stirring frequently.
Lastly I scooped up the beef and placed it in the oven at around 180 degrees Celsius for 10 minutes. It should slightly caramelise on the outside but be careful not to let it dry out.
Serve over mash potatoes with the carrots and sauce then dig in.