When they say, what do they want to do the knife, the question arises, just a knife or useful knife? A useful knife is such a knife, who can do a lot of useful things, rather than just putting it on a shelf and admiring it or showing it off to friends or neighbors.
Picture – Military police knives
A useful knife must be capable of performing tasks, for which it is intended. We must immediately decide what this knife will be needed for most of the time.. Knives can be used for many things. What is their main use - hunting, diving, cooking or cutting apples for drying? The main purpose of the knife depends not only on its shape and size, but also steel grade and heat treatment, cutting geometry, handle material and many other details.
A useful knife is such a knife, which the average person can use every day for routine "cutting" operations. A knife can do some of these things well., and bad - others. It could be used as a weapon, but, understandably, that a gun or a pistol would do the job better. It could be used to cut cucumbers into a salad., but a special chef's knife will do it much better.
A useful knife is a knife, which is useful at home for things like cutting apples, rope or paper, opening envelopes, wire stripper, what if, then for skinning hunting prey.
If the knife will be used frequently, you will want to have it with you all the time. but, if the knife is too big, you will have to leave him at home. If it is too small, you will not be able to handle any hard work. AND, sure, to carry a knife with you, you need to ask what knives you can carry with you, so as not to break any laws.
Knife blade shape
Blade shape should also be a compromise. For many jobs, a sharpened blade is the most suitable knife.. The only thing, which will be difficult to do with such a knife is to skin a killed animal. A knife with an edge in the form of a smooth curve along the entire blade is best suited for such cases.. Sometimes this shape is called "willow leaf".
Knife blade thickness
The thickness of the blade is also an important characteristic of the knife.. A thinner blade will cut with less effort, than thick. I remember, that the main function of a knife is to cut something, gotta aim for a thin blade. On the other hand, the blade must be thick enough, to withstand the loads applied to it. As always in life, there must be a compromise between ease of cutting and sharpening., one side, and strength, with another.
Most knives are too thick. This applies to both factory, and homemade knives. A good chef's knife, about 25 cm has a thickness around the handle of the whole 2,5 mm. And this is for a blade wide 50 mm. Correctly heat-treated such a knife cuts almost everything. Its blade may be a little too delicate for some tasks outside the kitchen., but not very much for many.
The best thickness of the cutting edge of the blade - after sharpening - different for knives for different purposes. Again: thicker - stronger, thinner - better cuts. The thickness of the cutting edge of the straight razor is about 25 μm or even less. The edge of a chef's knife for fine work after final sharpening has an edge thickness of about 0,1 mm. For small general purpose knives, thickness 0,25-0,40 mm is considered very good.
Currently, a large number of steels are used for the manufacture of knives.. Each of them has its own advantages and disadvantages.. If the knife is in a corrosive environment most of the time, then stainless steel knife is the obvious choice. If edge toughness and impact resistance is a necessary property of the knife, then you have to choose a good one carbon steel.
There are many Damascus knife lovers, eg, such, which turns out forge welding from such tool steels as American O1 and L6. Both steels are oil quenched. Domestic analogue of steel L6 - stamping steel 5ХНМ. Typical chemical composition of O1 steel: 0,95 % FROM – 1,1 % Mn – 0,6 % Cr – 0,6 % W.
Somebody think, that no carbon steel should be used for knives, because, they say, it quickly rusts and falls into disrepair. A good answer to this is: hunting rifle from Purdy, which may cost 100 one thousand dollars, can rust too, if you don't look after him. Valuables need care.
Knife handle or, may be, more correct – knife handle, should be comfortable and ergonomic. The knife can be held in various ways for various tasks. If the handle is made only for the grip, how do they hold the hammer, it may be uncomfortable for other grips.
Source:Tim Zavada, BLADE’s Guide to Making Knives, 2012