carbon steel

All posts tagged carbon steel

So, you want to forge knives… Well, I just started myself, only made a few blades so far. I have learned some information useful to beginners that might not be readily available online, or scattered all over the place. These lessons learned might save you some time, aggravation, even a few dollars.. Follow any advise here at your own risk, I am no expert and forging is inherently dangerous.

About forging: Forging is not just that, hammering a red-hot piece of steel into a blade. You need to consider what else comes into building a knife. A lot of time will be spent grinding, sharpening, and polishing. If using sand paper gives you unpleasant goosebumps, or you cringe at the thought of getting burned or cut, you might want to look into knitting. Heat treating is not as simple as plunging your steel in water. Some knowledge of metallurgy about different steels and what happens to them at different temperatures is a must. Annealing, normalizing, hardening and tempering are important phases in creating a blade. Then you need to make a handle, sheath, and sometimes apply different finishes. Building a knife is a whole process, forging is only part of it.

Forge: I started by building a charcoal forge. It worked, but it is slow and dirty, a pain in the ass, really. Sure, It only cost me $60, and I could have built a better one. Gas however is fast and clean. I bought a $200 forge on Ebay and never looked back. The next one will have a round shape though, and be covered with refractory cement instead of KAOWool. A round forge body creates vortexes resulting in a more even temperature and probably gas saving. With a hard refractory coating, you will never breathe dangerous ceramic fibers.. Coal is another good option, also dirty, but better in my opinion than charcoal. See my gas forge here.

Steels: Many beginners will try to find some scrap steel at the junkyard. You might get lucky finding what you want, but you might not. Spending hours hammering steel to find out that it won’t harden is no fun. I just ordered six 3/16 x 1” x 60” bars of 1080 from Admiral Steel for about $90 (with shipping)! That is enough to make from 30 to 40 large knives. Less than $3 per knife. Mystery steel is like mystery meat, you really don’t know what’s in it and most of the time, it doesn’t turn out to be that good. 1075-1080 is probably the best steel to start with. It is a simple steel, easy to heat treat and forge. You can temper it in a kitchen oven at 450F. Tool steels and other higher carbon steels require better temperature control and higher tempering temperatures, around 550-600F. It isn’t worth my time fishing for scrap in a junkyard. I would probably often have to discard half-finished blades, so the savings are really not significant enough. Buy good steel, pick one kind, learn it well, you’ll get consistent results allowing you to refine your process. More on steel selection.

Heat Treatment Anneal every time you stop working for the day. Normalize three times before hardening. Use a magnet to determine when the steel has turned to austenite and is non-magnetic. Go slightly higher, and let the blade soak for ten minutes at that temperature. If you forge or heat-treat too hot, your steel will decarbonize. Quench in warm oil (140 to 160F). Cold oil will actually not cool your blade as fast. Avoid motor oil, it’s too thick. Thin oil, such as ATF or thin mineral oil is better. Don’t move the blade sideways while it cools, but front and back. If you want to create a hamon by differential clay hardening, cover the back of the blade with a refractory like Satanite (1/8” thick layer). Temper immediately after hardening, three times one hour at 450F. If you use a different steel than 1060-1075-1080, find out what the numbers are, don’t just guess..

Anvil: I bought a cast iron anvil at Harbor Freight. It is way too soft! Here is when a trip to the junkyard might save you money. A 100Lbs hardened steel anvil will cost you $400 to $600. Find any piece of steel with a flat surface, as heavy as you can carry. Secure it to a solid base, so that you can forge standing up. Thanks to my friend Phil and his father at Seaboard Steel, I was able get a heavy piece of steel which originally was a jaw that grabs giant steel plates. It must be heat-treated because it is very hard. We welded it to an I-beam and a half-inch steel base.

Click on the image to enlarge..

Hammer and tongs: Almost any hammer will do (you might want to put a nice smooth finish on it’s face), but you need tongs to grab your blades. I started with a pair of wise-grips, but they are too short and awkward to use. Having a piece of red-hot steel fly out when you hit it is pretty scary. Don’t ask me how I know.. (well, I still have one scar on my ankle..) Start by forging tongues. It is easier than forging a blade, and you will need them anyway.

Click on the image to enlarge..

Not the best looking ones, but they work just fine..

Safety: Wear heavy leather gloves and clear eye protection (clear to see steel color). I have a welding jacket with leather sleeves that’s perfect for forging. Make sure nothing close to the forge can catch on fire. That includes your propane hose in particular! Wear a respirator when grinding or changing your ceramic fiber forge insulation. Don’t forget, you’re building knives, they can get really sharp! Blades can fly off your hands while grinding, specially when using buffing wheels. You must be conscious of safety all the time. You don’t want to end-up in the hospital or dead because of a hobby!

Information: It is easier to start with some help. Browse the following forums online:

Document you progress. You might discover that a blade you forged displays great characteristics after some use, and not remember how you made it..

I highly recommend Wayne Godard’s $50 Knife Shop book:


Wayne Goddard’s $50 Knife Shop, Revised
And Tim Lively’s DVD:


Knifemaking Unplugged

I will add to this article once in a while as I discover new tips or pitfalls to avoid. Anyone with more experience than myself, that’s almost anybody able to forge a decent knife at this time, please add any advise for beginners you may have in the comments section below. Many thanks to the members of bladeforums.com for their feedback on this article!

After weeks of consideration and research on the web, I finally decided to buy a katana. Not a cheap wall-hanger, but a practical sword, forged by hand and differentially hardened. I am very familiar with knives, even started to forge my own. Swords however are mostly unknown to me. Why would a grown man buy a sword you may ask, well, I have a few reasons, and they have nothing to do with the “cool” factor. Swords are not toys, but deadly weapons. I place them in the same category as handguns and rifles. I came to believe that they are one of the best home defense weapons available. My interest in knives came from the staggering number of designs found for such a simple, primary tool. Metallurgy, the forging and hardening processes have always fascinated me. I have barely scratched the surface of that art, but I can certainly appreciate the skills it takes to forge a blade longer than a few inches, then harden and temper it properly. My life-long interest and practice of the martial arts also influenced my decision. I have long ago found out that most Asian disciplines only work in their context. Russian Systema however works in any circumstances and can make use of any weapon. Give me a frying pan and I’ll be immediately efficient with it using Systema principles. A sword, though presenting some challenges, shouldn’t be too much trouble. Of course, I will use a dull one or bokken for practice. Other sword designs were interesting, but the Japanese katana in my opinion is the best sword. It is light, razor sharp, and simple in design. Nobody wears armor these days, so a heavier sword would make little sense. The way these swords are made is also fascinating. Even if you have no interest in swords, you can’t but admire the dedication and skills of Japanese sword-smiths in their pursuit of perfection. I never get tired of watching the following documentary from National Geographic:

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I can’t pay three highly skilled artisans for three months to forge me a blade, so I have to accept some technological shortcuts. Modern steels like 9260 Silicon Alloy Carbon Spring Steel are even better than traditional tamahagane. It’s not traditional of course, but much cheaper. The folding process becomes superfluous, since the carbon content of modern steel is constant throughout the material. I would love a folded blade, but the cheapest ones, forged in China, start at around $1000. More than I am willing to spend for a first purchase. A San-Mai construction like my Cold Steel Master Tanto would be desirable too, but simply too expensive. There is one feature I really want however, and that is a differentially, clay-hardened blade. This process of covering the back of the blade with thick clay before quenching in water produces a very hard edge and a soft back (watch video above). This way, a sword will bend but not break, while still holding a razor-sharp edge. It also produces a visible line of hardness called the hamon. Most replicas have a fake one, acid-etched on the blade. I can’t accept “fake” anything, so my choice becomes fairly limited for an affordable real sword. Thanks to companies like CAS Hanwei and Cheness Inc., real forged blades from China are available, starting at around $160 for something that won’t come apart in your hands and take a lot of abuse before breaking. Shell-out $200 to $300 and you get a serious tool. My choice is the Kaze Ko-Katana. With a 21-inch blade, this katana is about seven inches shorter than a regular sword. These swords are also called chisa katanas, and are easier to use in tight places. Here is another review of the Kaze (watch the cutting test video). I got a 10% discount and ordered mine for less than $200, with free shipping.

Proceed to the full review

An often overlooked home self defense option is the sword. They work as well today as they did centuries ago, as we can read about in this recent news article. A Baltimore student killed an intruder with a Samurai sword. At short to medium range, a good sword is deadlier than any gun. It never jams, and never runs out of ammo. Modern reproductions of Japanese katanas made in China have come a long way and are now available for a couple hundred dollars. So, is a sword the self defense weapon of choice?

Well, it depends.. As with any weapon, are you willing to spend the time to learn to handle it safely and practice on a regular basis? “It’s just a sword” you might say, but a 28-inch razor sharp blade can ruin your day very fast; just look at this:

Sword injury.

Sword injury.

Picture from the excellent site:
Swords Buyers Guide

And this is what happens when you mess with a cheap stainless steel wall-hanger:

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Avoid stainless steel like the plague. Be very suspicious of movie related products or cheap “Ninja” katanas. A sword, even a bad one, is very dangerous. The difference about a bad one is that is is as dangerous to you or people around you as it would be to an intruder. It only has to touch you to cause gruesome injuries. Sword makers offer non-sharpened models called iaitos, used in the discipline of Iaido, which is the art of drawing. They are a good investment and insurance policy for your early training..

As far as Japanese sword arts, you might want to look into Iaido, Kenjutsu, Kendo or Shinkendo. My opinion is that your best bet is an art that actually teaches to cut targets (Tameshigiri). I would personally look into Shinkendo or Toyama-Ryu, which are modern swordsmanship systems. You don’t have to become an expert, but learning a few basic techniques, cuts and safety are a minimum.

Are you willing to spend $200 or $300 for a decent blade made of carbon steel, forged and mounted properly? These figures are actually cheap compared to real Japanese swords starting at around $6,000. CAS Hanwei and Cheness Inc. are the major manufacturers of decent quality reproductions. Hanwei also offers medieval swords worth a look, if you prefer the Highlander type of hardware! Cold Steel also has a good collection of practical swords (I like their Chinese War Sword). See below how Cheness forges a blade:

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Though not made in Japan (Nihonto or modern Shinken), the Chinese reproductions are real swords made by hand using somewhat similar techniques. For most people, they are the only accessible models, with a price range of about $150 to $3,000. For home defense, a $300 spring steel model would do just fine. I like the cheness Ko-Katanas, which are a shortened version for tight spaces, like a house. You’ll never (hopefully) carry your sword outside your house, so you don’t need a long one. A wakisashi would do fine as well (one-handed). Watch below as Paul Southren from Swords Buyers Guide tests a Cheness katana. Very impressive.

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Carbon steel rusts.. You will have to clean and oil your sword at least every other month. It isn’t a high price to pay to keep your weapon ready and in good shape. Aside from that, a good sword will never let you down. If you practice swordsmanship, you also have an excuse for owning one and grabbing “the closest thing that could be used as a weapon” when it comes to explain to a judge why you cut a robber in half instead of calling 911 and waiting for the cops while getting beaten-up or killed.. And yes, the above mentioned swords will cut someone in half if you practice long enough to get a perfect cut. More often than not however, just showing the sword tends to convince intruders to turn around and start running.

I may have a preference for Japanese swords just because of their light weight, but any good quality medieval or antiquity reproductions would do fine, from European blades to sabers, scimitars, Chinese swords, there is something out there for everyone. With anti-gun laws looming on our horizon, a sword might be a good choice. It sure beats a jammed gun any day. You never have to buy ammo, so practicing might involve just a bit of your time and sweat, maybe a membership fee and a few tatami mats.. If you do decide to get one, be responsible, get professional advise, and learn about self-defense laws. Be safe đŸ™‚

I had noticed those odd-shaped knives before, but really got interested in purchasing one after reading the excellent James Clavell book, “Whirlwind” where, among a flurry of characters, a few British Gurkhas roam Iran on a covert operation during the 1979 revolution. They are armed of course with Nepal’s “official” knife, the Kukri, or Khukuri. After some research on the web, I decided to trust Khukuri House with my hard-earned money, and settled on the Raw Panawal model.

Raw Panawal Kukri

Raw Panawal Kukri

I didn’t want a highly polished blade because it was to be used for camping and, as it turned out, a few other unexpected chores around the house. The knife is hand-made form a truck suspension spring, and let me tell you, it is a heavy chunk of steel. As you can see on the photo, the tip is a wide drop-point, perfect for chopping, as the handle shape also suggests. The box arrived from Kathmandu a couple weeks after I paid the $45 plus $35 shipping on the site. Now, how often do you receive parcels from Kathmandu? The mailman must have scratched his head about that one.. The whole knife was nicely wrapped in heavy paper and plastic, fully oiled. My first impression was “It’s big,” then “It’s heavy.” I tried to shave hairs off my arm (if you ever noticed, I often have bold patched on my forearms ;-), but to no avail. I took it to the sharpening stone right away, coarse, then fine, then cardboard; still, no shaving, but more on that later..

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[tip]The best knives are made of carbon steel. This means that they will rust very quickly. If you own a carbon steel knife, clean it and keep it oiled after every outing, or every other month. I use an old electric toothbrush with dish detergent, then any oil at hand at the time..[/tip]

My friends and I were going to have a bonfire in the backyard, and I decided to clean-up the area of low palm frowns. The ten-inch blade cut through like a hot knife in butter; well, not quite, but I certainly didn’t have to exert much effort to accomplish the task. The weight of the blade did the work for me. I am not so worried about sharpness anymore, this one is a chopper and a keeper!

The rosewood of the handle seems to be affected by changes in temperature and humidity. I noticed the problem when the rivets felt as if they were slightly bulging out, and the wood separated from the handle on one side by maybe half a millimeter (not much at all). It isn’t really a problem per say on a work knife. I would be pissed if it happened on a $200 knife, but let’s face it, I paid $85 total. The assembly feels as solid as ever, so I am not worried about smashing it on a log with all my strenght. This is what my friend Ted did when he borrowed it from me to spilt logs! He brought it back in one piece, and without any dents. To whomever built it and heat-treated it, my hat off to you sir..

I haven’t used my Kukri for camping yet, but it will certainly be with me on my next trip.


 
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I have abused it removing baseboards in my bedroom, chopping through nails and all, without visible harm. If someone broke into the house at night, it would be high on my list of things to grab to go investigate (I always have a few other choices at hand).. As to getting it to shave hair, I gave up. The concave edge makes it difficult, or maybe I am not using the right method. Anyone? I even dropped it at a shop to have it professionally sharpened, it came back just the way I brought it in, reasonably sharp, but not “razorly” so.. That said, a razor edge is not needed on such a beast.

I may sandblast and parkerize it, if I get bored enough.. It would give it a nice dark-gray finish impervious to the elements, and I wouldn’t have to oil it very often. I’ll post my method if I ever get to it.

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This knife will come with me every time I hit the woods. It is well built, with a very strong edge. Get one and you’ll be the coolest looking camper around with that thing on your belt! If that’s all you have, and you camp in remote areas, it will give you some piece of mind on dark lonely nights. Now, I’m ready for a trip, who else is coming?

Update October 17, 2009: I just used the knife to cut a tree! Not a bush, a real tree. The trunk was about five and a half inches in diameter. It took mere minutes to chop through it. While cutting it to pieces, I even accidentally hit the cement below in the driveway, twice. No chipping of the blade! I didn’t even bother resharpen it after, it was just fine..

James Clavell’s book is a great adventure novel that, although from a British perspective, sheds a lot of light on middle-east politics and religion. I highly recommend it..