April 2010

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Introduction to Carbide Drills

22 Apr 2010 | : Uncategorized

Tungsten carbide is a very hard material. It can therefore drill into very high density materials such as stainless steel. When one refers to a carbide drill, it is generally a tungsten carbide drill. But there are other kinds of carbide too. There are certain advantages of carbide drills which result from the hardness and strength of the material they are made from, which make them among the best kinds of drills available. However, this also make them more costly.

Terminology

When one speaks of a drill, oftetimes what is meant is the actual drill bit that is used to do the actual boring. However, the drill machine that has the motor and which holds the bit and is also correctly referred to as the drill. References to carbide drills at this site, will be to the drill bit itself. We will get more specific when we look at the different types of carbide drills, as depending on the type, it might just be a part of the bit that is actually made of carbide.

Advantages of Carbide Drill Bits

One of the advantages of carbide drill bits over the more common steel bit, is that they last longer, so long as nothing drastically wrong happens. Drills experience “Wear and tear” because the heat generated due to the friction between the bit and the surface being penetrated, causes the dulling of the bit. As a result, the drill bit needs regrinding from time to time, to maintain it’s cutting edge. However, there is a limited number of times that regrinding can be done before the drill becomes effectively useless. There is also the matter of the structural integrity of the bit, which gets compromised due to the repeated heating and cooling that the bit undergoes as it is put to work. As carbide drill bits are tougher and more durable than their steel counterparts, they do not deteriorate as easily, and therefore have a longer lifespan, up to 25 times as much.

To appreciate another advantage of carbide drill bits, we need to understand what is meant by drill tolerance. The tolerance of a drill basically is a measure that indicates the accuracy one can expect from the drill bit. It in effect is the difference between the diameter of the bit and the diameter of the largest expected hole generated from actually using the bit. The tolerance is associated with the size of the drill bit, as well as the type. As would be expected from the explanation of what tolerance refers to, the lower it is, the more accurate the bit. Carbide drills have the lowest tolerances and are therefore the choice of drills for any task that requires high precision.

Different kinds of Carbide Drills

As indicated earlier, there are different kinds of carbide drills. Essentially, there are the solid and the tipped. A solid carbide drill is one in which the whole bit is made of carbide. This is contrasted with the carbide tipped drill bit, where just the tip of the bit is carbide, and the rest might be of the more common steel. There are advantages and disadvantages to the different kinds. (See links for each for more details).