The Mechanical Lumberjack

I've seen some people make axes from circular saw blades, but none of them have a spinning blade! So, I made one that spins. It's hung on a hickory sledgehammer handle, so I had to lengthen the slot so that it was longer than half the diameter of the circular saw blade. It's got a 1/2" diameter bolt for the axel and a 5/8" brass bushing to spin around. Currently, it has zero practical value, but I'm going to shorten the handle and see if it's any good for throwing. Edit - If you like kind of offbeat things that are actually kind of cool, check out my latest business that is a website for electric vehicle charger real estate and real estate for other small machinery and hardware like vending machines and shipping container farms. 

There are hundreds, if not thousands, of inexpensive, and let’s face it, cheap, knives that are for sale online. I’m talking about knives in the under $10 segment  which you would not want to rely on for survival, but can make for a decent Every Day Carry (EDC). Since I’ve only recently taken an interest in knives and I’m cheap, I’ve spent a lot of time in this realm. I’ve found 3 knives that while varied in size, shape and weight, are all a good value. This is a review of those knives, particularly of the initial quality. I’ll follow up with a post about longer term quality, and I have a very special destructive (!!!!) test in mind for these inexpensive blades. The three knives I purchased are the Elk Ridge Wood Gentleman, the Tac Force EMT and the MTech Xtreme Ballistic. From Left to Right: Elk Ridge, Tac-Force, and MTech From Left to Right: Elk Ridge, Tac-Force, and MTech Right off the bat, I think the Elk Ridge is a beautiful knife, but I’m definitely partia...

I'm going to go into significant depth about ceramics, and really, the composition of most ionic solid materials, hopefully without dragging on forever. So, let’s start with the basics. Grinding stones are made from ceramics. Ceramics are a class of materials (just like pure elemental metals, metal alloys, non-metals (such as oxygen, nitrogen, carbon), and polymers (plastics and rubbers) are all classes of materials) that are composed of metal elements that are combined with non-metal elements. There is a large difference in the electronegativities (the strength at which they hold onto electrons) of the elements, so one element  (the metal)  give up an electron  (or a few electrons in some cases) to the other element (the non-metal). This is called ionic bonding, and ceramics have ionic bonds. The particular ceramic that grinding stones are typically made from is a mineral (minerals are generally ceramics) called corundum, which is chemically known as aluminum oxide...

First and foremost, some definitions are required. Ancient Damascus blades were not made from Damascus steel, they were made from Wootz steel that was produced in India and exported to Damascus where the blades were made, so really, Damascus STEEL isn't a thing, but Damascus BLADES are. Modern "Damascus Steel" is not produced in the same way that the ancient Wootz steel was (it's still a mystery, but the microstructure found in the ancient blades shows a significant difference in elemental composition and microstructure found in modern blades), and it uses a process called Pattern Welding. Pattern Welding is, essentially, a process where different types of steel ( see this post about steel phases ) are welded together and heated, folded, and stretched (kind of like kneading dough ingredients together) repeatedly to create a visible pattern of the different steels and work-harden the steel (I guess I'll have to do a post about work-hardening) to improve its mechani...

From the title of this post, you should suspect that I'm going to focus on wood handles, and I will save composite handles for another post. There is some overlap between the two, like how in a wood handle a continuous straight grain makes the handle stronger than a discontinuous grain, and similarly in a composite handle, straight continuous fibers (usually fiberglass) will be stronger than discontinuous (short/chopped) fibers. An axe handle should be split from a stave (a narrow piece of “raw” wood) instead of cut out of a board. The grain of the wood should be continuous from end to end, or the shock from use will cause the handle to break apart (think baseball bat). Long, straight-grained woods such as hickory or ash are traditionally chosen for axe handles because they are strong and produce long, straight staves, and they have good mechanical material properties, like many other hardwoods. An axe handle should be from a log that is straight, without twists, branches, or bur...

I'm going to focus this post on the steel used to make an axe, but the principles apply to all steel products (like knives) because I'm just going to be talking about the properties of the steel itself. Firstly, I think it's prudent to define what is steel and what is not (i.e. variations, like stainless steel). Steel is a mixture of iron, which is soft yet tough, and carbon, which is very brittle and stiff in most of its many forms (allotropes as scientist like to call them - diamonds, graphite, graphene - they're all pure carbon, but have different molecular structures) and when a small amount of carbon is mixed into iron (~0.5-2%) the resulting mixture is called steel. Stainless steel is very different - it will not corrode as easily, but still corrodes in harsh environments like acidic and basic solutions, it is significantly softer than steel, and it has 10-20% of nickel and/or chromium added to the iron/carbon mixture, which makes it more expensive that regular ...