Drill BitsWhen most people think of drill bits they think of drill bits they think of the simple tool that can be found in any house or machine shop. The drill bits are relatively simple in design and are typically used for drilling through wood and metals. Most people don’t realize that when companies drill in the earth for oil they also use drill bits. However, the drill bits used in this process are very complicated in nature, not to mention costly. These drill bitts cost on average between $30,000 and $50,000 dollars, but can cost as in the 150,000+ range. Due to the high cost of these bits, it is important for any supply manager working in this industry to have an understanding of how they work and their intended uses. To completely understand the engineering that goes into these bits would probably require someone to have a degree in mechanical or petroleum engineering. However, with some basic understanding of the different kinds of bits and the manufacturing process behind them, it is possible for a supply manager to properly identify and purchase the proper bit for the project he/she is working on.The intended use of the drill bits is quite easy to understand. Like the drill bits in found in a simple hand drill, all drill bits are intended to make a hole. The major difference being that you are drilling in rock formations and the hole is 5-30 inches in diameter. These are the two main factors in determining which type of drill bit that should be selected. There are many categories and sub categories of drill bits that drill into rock formations. However, in the modern oilfield the most commonly used type of bit is the rotary drill bit. There are two main types or rotary drill bits, drag bits, and rolling cutter bits.Drag bits are a type of drill bit that uses a fixed cutter blade to drill into a rock formation. Drag bits physically plow or machine cuttings from the bottom of the hole. Unlike rolling cutter bits, drag bits have no moving parts, which decreases the likelihood that unwanted material could be left in the hole. Drag bits can be further broken down into three categories base on the design and the material they are comprised of.