Advice on making a a big chopper survival knife

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NBKnife

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Nov 4, 2015
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Hello, I am relatively new in knife making, and I have only used mystery steels and salvaged steel. I plan on making a big survival knife that I can use for cutting and chopping. I managed to find steel from a big blade that was used for cutting paper sheets in stacks. The problem is that it is around 6,5 mm thick. Is it okay for a knife or is it too thick??

I also have 1.5 mm thick sheets of steel that were used as blades for cutting tobacco in the cigarette factory in my town. Currently they are over 62 HRC, but I am afraid to anneal them because I don't know if I would be able to heat treat them without warping due to them being so thin. Should I work with them as they are, with a lot of cooling down, or can I anneal them first??
 
The paper cutting blade is probably D2, but don't quote me on that. I definitely wouldn't try annealing either one, as air hardening tool steels (which I'm sure these are some sort of) need very specific ramps, and temperatures. I have the equipment to annealing air hardening steels, and I still won't try it on mystery metal. Even if the big blade is D2, it still wouldn't be my first choice for a chopper. D2 is more for leather working tools, bird and trout's, Skinner's, ect in my mind.

My recommendation would be to order a bar of either O1 or A2 from a machinist supplier (or you can find deals on eBay occasionally, look for Starrett or presco precision ground) These are both very nice to work with, and come dead soft and ground to a fine finish and tolerance. O1 is easy enough to do a decent heat treat (it will make a serviceable knife, but won't perform quite as well as is absolutely possible) with a forge or oxy acetylene torch, and a quench of corn oil, mineral oil, or automatic transmission fluid.
A2 needs a heat treat oven, but it's so commonly used in industry that a lot of machine shops, and any place at all that does work on dies will be able to heat treat it.

Both are very tough steels, and make great choppers
 
I agree with the above advice. My suggestion would be to use 5160 or 9260 steel. It will be simpler to HT and is very tough.
A2 would also be good if you have a source for HT.
3/16" (roughly 4.5mm) is plenty thick enough for a survival knife. Many are only 1/8" thick (3mm).
 
Those would be good choices as well. I didn't recommend them only because I don't personally have experience using them.
3/16 stock with a full flat grind should make quite a nice chopper. I've done some 4.5" drop points in 3/16 A2 with a full flat grind, and they are damn near impossible to tear up. A bit thick for my taste, but they still cut decently and good luck breaking one.

I've admittedly done hundreds of knives from salvaged sawmill blades, but it's not something I'd recommend to the beginner.
 
Both D2 and A2 are great steels but I think D2 is a bit more picky in the heat treat to really make it preform. A2 is an amazing steel and works well on a wide range of knife sizes and styles. It also needs attention in heat treat to really make it scream. Both steels are good and have there place but I would not consider them a beginner steel. I would not consider them even if you had a
Shop that would heat treat them for you unless thy knew how to heat treat these aloys for knives. 5160 is a great beginner steel, very forgiving and easy to grind and finish but it's also tough. O1 is also good but I don't know if I would stick it in the newbie category just becaus it needs a heat treat oven to really be all that it can be. The same is true with 1095. I'm not saying that you cant get a great heat treat in a back yard BBQ on these steels but I'm saying it takes skill if your going to try it. 1084 is also
a great starter steel that heat treats easy and is cheep.
 
A2 definitely has its specific requirements. I've played around with ramp rates and various other things a fair bit to really squeeze the most out of it. If everything is spot on (including geometry of the blade) it can be very impressive.
I've found 1095 to be rather finicky at times, and I'd much sooner recommend O1 for a beginner. O1 in my experience is a fair bit harder to really screw up with.
1084 is a great recommendation, and I really can't argue with that. 1080 makes quite a decent blade as well and would be another good option.
 
When it comes to big chopping blades, I'm in the camp that likes to start with thick stock, and then add distal taper to make it easy to maneuver and also hit with authority at the same time. Possibly even adding pommel weight to adjust the sweet spot for chopping. If the stock starts out thin, you don't really have much room to go with tapers.
 
15n20 and 8670 are great in this application as well.

Heat treat will be the defining factor, not steel choice. Pick the steel you can heat treat the best.
 
I'd definitely go with the advice of Willie71.
I can't see why using something like D2 for a chopping/survival knife. It will tend to have a too brittle edge for chopping and will be a pita to sharpen in the field. And to get acceptable results, top of the notch HT is demanded, as too many thing could make the blade even worst.

A 0.70 - 0.84 C steel will be more suitable, and the little alloy, as per Willie71 suggestions, will make it shine even more for your application.
If corrosion would be a concern all you will need is bringing a little oil with you to take care of the blade before putting it aside.
 
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