An Ode to Steel.
The following are descriptions of the scientific properties of spears. If you are looking for the material for the perfect spear it would have a high tensile strength, high fatigue strength, high toughness, be impact resistant, and be non-corrosive. All at a reasonable price.
Tensile strength. Tensile strength is defined as the maximum load in tension a material will withstand before fracturing, or the ability of a material to resist being pulled apart by opposing forces. Also known as “ultimate strength”, it is the maximum strength developed in a metal in a tension test. The tensile strength is the value most commonly given for the strength of a material and is given in pounds per square inch (psi) (kiloPascals (kPa)). The tensile strength is the number of pounds of force required to pull apart a bar of material 1.0 in. (25.4 mm) wide and 1.00 in. (25.4 mm). Our spears have been tested from 1950 psi to 2150, which means that they are extremely strong.
Fatigue strength. Fatigue strength is the maximum load a material can withstand without failure during a large number of reversals of load. For example, a speared fish subjects the spear to two tensile forces, one at the top portion of the shaft leading to the floatline, and another forces exerted on the shaft by the fish. As the fish fights, the spear is often rotated, so there is a repeated cyclic change in tensile and compressive strength along the length of the shaft. Fatigue strength values are used in the design of aircraft wings and other structures subject to rapidly fluctuating loads. Fatigue strength is influenced by microstructure, surface condition, corrosive environment, and cold work.
Toughness. Toughness is a combination of high strength and medium ductility. It is the ability of a material or metal to resist fracture, plus the ability to resist failure after the damage has begun. A tough metal, such as cold chisel, is one that can withstand considerable stress, slowly or suddenly applied, and which will deform before failure. Needless to say, we mean it when we say “our stuff is tuff.”
Impact resistance. Resistance of a metal to impacts is evaluated in terms of impact strength. A metal may possess satisfactory ductility under static loads, but may fail under dynamic loads or impact. The impact strength of a metal is determined by measuring the energy absorbed in the fracture. If you were to take a spear and rapidly shoot it at point blank range into an anvil you would get an indication of the spears impact resistance, but obviously we don’t recommend you do this.
Hardness. Hardness is the ability of a metal to resist penetration and wear by another metal or material. It takes a combination of hardness and toughness to withstand heavy pounding. The hardness of a metal limits the ease with which it can be machined, since toughness decreases as hardness increases. Our spears are relatively hard, having a Rockwell hardness of 52-56, and require diamond tipped machinery to notch and drill.
