- Joined
- May 12, 2021
- Messages
- 11
In the past couple months I've been contacted by a mother asking about a knife for her son who is in the marines. I've never made a knife for military or many "tactical" knives so, on the one hand, I don't have any experience with this. On the other hand, looking at the issued knives and what people seem to carry, I think I could make a much better knife. I decided to make two knives, destruction test one of them, and if the testing went well, I would sell her the other one. Here is the testing I did and my thoughts on it. I'd appreciate your thoughts!
Alright, I have got both of them through heat treatment and have ground and tested one of them. Some results which are confusing, hoping to get some thoughts. First off, this is my first time using Nitro V, though its sister AEB-L has become one of my primary steels. I austenitized at 1920 for 15 minutes, quenched in Aluminum, cryo'd with dry ice, and tempered at 400 degrees. I flat ground the edge to about 0.017 before sharpening. Behind the secondary bevel thickness of around 20 thou. This is thicker than I normally go, since usually I make knives optimized for slicing, not abuse. Honestly, some of these tests seem a little silly, but I figure a military knife could be more general use tool than knife.
Testing: Nothing scientific, but I was hoping it would be informative. I cut some cardboard, it held an edge fine and stropped back to sharp. Then I batoned some wood. It went through the clear Douglas Fir fine, as long as the blade could be reached from the other side. It had a hard time going through a knot, however, I'm guessing mostly because of its small size; the edge was perfectly fine after this. Chopping antler, not much happened, is it possible for antler to soften with age? I took a random bolt, probably 1/4in from the scrap bucket, and started hammering the blade through it. At first it mushed up the edge, which would make me think the blade is on the softer side. However, once about halfway through the blade chipped off in a crescent shape. I tried this again with some 304/303 1/8 pinstock, and though it cut through it, it chipped the blade as well, the steel acting exactly like it did with the bolt, just on a smaller scale. This is the main point of interest for me, as I'm a little confused. (Side note, the grain looks extremely fine, but I'm not sure how much you can tell about grain size after tempering). I did a little more testing, like cutting a 30-06 cartridge a few times and punching the tip through a coarse 1in brick. Both dulled the blade. And that's it.
Questions: How do people get blades to go through a bolt without chipping? Is it that their heat treat is dialed in, their edges are thick, and/or that they are using a different type of bolt?
Why did my blade mush up first, without microchipping, until about halfway through, when it chipped? Could a possible heat treat of harder steel, which gives more strength and resists deformation actually improve toughness, do you think? I know Larrin Thomas says that at a 450 degree temper he got lower hardness and toughness than at a 350 degree temper for Nitro V, which is interesting.
Thoughts: I'm thinking that if this knife (or it's brother) will be used more as a general cutting tool rather than chopping through walls and stuff, it would do very well. The question is whether a handmade knife made for active duty is/should be expected to break through concrete walls and stuff or not. Your thoughts? If you read this, thank you.
Alright, I have got both of them through heat treatment and have ground and tested one of them. Some results which are confusing, hoping to get some thoughts. First off, this is my first time using Nitro V, though its sister AEB-L has become one of my primary steels. I austenitized at 1920 for 15 minutes, quenched in Aluminum, cryo'd with dry ice, and tempered at 400 degrees. I flat ground the edge to about 0.017 before sharpening. Behind the secondary bevel thickness of around 20 thou. This is thicker than I normally go, since usually I make knives optimized for slicing, not abuse. Honestly, some of these tests seem a little silly, but I figure a military knife could be more general use tool than knife.
Testing: Nothing scientific, but I was hoping it would be informative. I cut some cardboard, it held an edge fine and stropped back to sharp. Then I batoned some wood. It went through the clear Douglas Fir fine, as long as the blade could be reached from the other side. It had a hard time going through a knot, however, I'm guessing mostly because of its small size; the edge was perfectly fine after this. Chopping antler, not much happened, is it possible for antler to soften with age? I took a random bolt, probably 1/4in from the scrap bucket, and started hammering the blade through it. At first it mushed up the edge, which would make me think the blade is on the softer side. However, once about halfway through the blade chipped off in a crescent shape. I tried this again with some 304/303 1/8 pinstock, and though it cut through it, it chipped the blade as well, the steel acting exactly like it did with the bolt, just on a smaller scale. This is the main point of interest for me, as I'm a little confused. (Side note, the grain looks extremely fine, but I'm not sure how much you can tell about grain size after tempering). I did a little more testing, like cutting a 30-06 cartridge a few times and punching the tip through a coarse 1in brick. Both dulled the blade. And that's it.
Questions: How do people get blades to go through a bolt without chipping? Is it that their heat treat is dialed in, their edges are thick, and/or that they are using a different type of bolt?
Why did my blade mush up first, without microchipping, until about halfway through, when it chipped? Could a possible heat treat of harder steel, which gives more strength and resists deformation actually improve toughness, do you think? I know Larrin Thomas says that at a 450 degree temper he got lower hardness and toughness than at a 350 degree temper for Nitro V, which is interesting.
Thoughts: I'm thinking that if this knife (or it's brother) will be used more as a general cutting tool rather than chopping through walls and stuff, it would do very well. The question is whether a handmade knife made for active duty is/should be expected to break through concrete walls and stuff or not. Your thoughts? If you read this, thank you.
