How Does a Drill Bit Work? Private1 month ago - Automobiles - Battle Creek - 4 views
A drill bit is what actually cuts into the rock when drilling an oil or gas well. Located at the tip of the drillstring, below the drill collar and the drill pipe, the drill bit is a rotating apparatus that usually consists of two or three cones made up of the hardest of materials (usually steel, tungsten carbide, and/or synthetic or natural diamonds) and sharp teeth that cut into the rock and sediment below.
In contrast to percussion drilling, which consists of continuously dropping a heavy weight in the wellbore to chip away at the rock, rotary drilling uses a electric hammer drill bit to grind, cut, scrape and crush the rock at the bottom of the well. The most popular choice for drilling for oil and gas, rotary drilling includes a drill bit, drill collar, drilling fluid, rotating equipment, hoisting apparatus and prime mover.
Types Of Drill Bits
There are a number of different types of drill bits. Steel Tooth Rotary Bits are the most common types of drill bits, while Insert Bits are steel tooth bit with tungsten carbide inserts. Polycrystalline Diamond Compact Bits use synthetic diamonds attached to the carbide inserts. Forty to 50 times stronger than steel bits, Diamond Bits have industrial diamonds implanted in them to drill extremely hard surfaces. Additionally, hybrids of these types of drill bits exist to tackle specific drilling challenges.
Different configurations work better on different formations; so a number of different drill bits may be inserted and used on one well. Additionally, drill bits have to be changed due to wear and tear. Drilling engineers choose the drill bits according to the type of formations encountered, whether or not directional drilling is required, for specific temperatures, and if well logging is being done.
When a drill bit, like a masonry drill bit, has to be changed, the drill pipe (typically in 30-feet increments) is hoisted out of the well, until the complete drill string has been removed from the well. Once the drill bit has been changed, the complete drill string is again lowered into the well.
Cutting metal with cutting wheels
Plenty of manual cutting applications call for a hand-held grinder and cutting wheel. Cutting sheet metal, sizing a piece for fabrication, cutting out a weld to refabricate it, and cutting and notching in pipeline work are just a few examples of what can be accomplished using a grinder and cutting wheel.
The Basics of Cutting Wheels
The main considerations in using resin cutting wheels include the cutting application, the tool being used—such as a right-angle grinder, die grinder, or chop saw—desired cutting action with diamond saw blade, the material being cut, and space. Wheels typically provide a fast cutting action, long life, and tend to be cost-effective.
Proper Positioning and Other Tips
In addition to paying attention to designations for RPM rating, size, and material, you should also follow these tips when using resinoid-bonded abrasive cutting wheels.
Use the cutting wheel at a 90-degree angle, perpendicular to the work surface.
Apply the proper amount of pressure—not too much, not too little—to allow the cutting wheel to do the work. Always avoid pushing too hard on the wheel, which can cause the grinder to stall or kick back or give you a much less efficient cutting action. It also increases the chances that you will slip or lose control of the tool, which can cause damage or injury.
Hole saw basics
Spade bits are the tool of choice for drilling holes up to about 1-1/4 in. in diameter for running electrical wiring and other uses. But when it comes to drilling really big holes for locksets or plumbing pipes, reach for a HSS hole saw. A hole saw is a steel cylinder with saw teeth cut into the top edge. Hole saws don’t cut as quickly as large boring bits driven by a pro’s powerful 1/2-in. drill. But boring bits are expensive ($30 plus drill rental). Hole saws, on the other hand, are readily available at hardware stores and home centers for as little as $5 and work with a standard 3/8-in. drill. Cutting clean holes with hole saws requires a little skill and practice. Here are the key techniques that will make the task safer and give you the best results.
Proper setup is important
Mount the correct-size hole saw in the arbor. If your concrete hole saw has an adjustable center bit, make sure it protrudes past the toothed edge of the saw about 3/8 in. (Photo 2). If the center bit has a flat spot on its shank, align this with the setscrew. Then tighten the setscrew to secure the bit. Finally, tighten the holesaw in the chuck of a corded 3/8-in. variable speed drill. Cordless drills won’t have enough power unless they’re 18 volts or larger.
Start slowly and hold on tight
Photos 1 – 4 show how to drill a hole in a wood door for a lock or door handle, but the same techniques apply for drilling other holes. When you need a clean, splinter-free hole, drill in from both sides (Photos 1 and 4). The key to getting a perfectly straight hole is to ensure even contact at the start. That will put your drill at a right angle to the door (Photo 3).