Drilling and Boring Tools
Electric drilling and boring tools are versatile instruments that have changed the plumbing profession – they have greatly shortened the amount of time it takes to install pipe.
Drilling and Boring Tools
Drilling tools allow you to make holes in a building's structure quickly. But using a drill with skill and care requires training and experience. While drills are less dangerous than some tools, like saws, using or maintaining drills improperly can lead to injury.
Follow these guidelines to using drilling tools successfully:
1. Successful drilling depends on preparation. If possible, place the work piece you plan on drilling in a clamp or a vise. This leaves both your hands free to operate the drill. It also prevents the work piece from moving around as you drill.
1. Before you drill a hole in metal, establish and mark a precise center point on the metal’s surface.
2. Drilling is something of an art form. To do it well, you have to consider several factors: the drill's rotational speed (which is defined by its rpm), the type of drill bit, the diameter and depth of the hole being drilled, and the material properties of the work piece.
Portable Electric Drills
The portable electric drill, sometimes called a pistol drill because of its shape, is used to drill holes in structural materials so that pipes can be run through the holes and the fixtures can be installed.
This basic drill has a motor built into the pistol-shaped body.
The chuck is a gripping mechanism that houses the drill bit. After the drill bit is inserted into the jaws of the chuck, the bit is locked in place by tightening the chuck. The chuck is tightened either by a key or, in newer models, by hand.
Always unplug the drill when tightening and locking a drill bit into place.
Portable Electric Drills
Drilling with a right-angle portable drill can be dangerous, so these drills should have a clutch that will kick in if the drill bit sticks in a hole. This feature prevents you from losing control of the drill and possibly getting hurt.
The two other kinds of drills are the hammer drill and the rotary hammer drill.
The hammer drill combines the force of a hammer with the boring capability of a drill. Its hammering action penetrates dense material such as concrete or masonry, and the rotating bit removes the chips.
The regular hammer drill is used for drilling holes to set small anchors that secure piping to a structure. The rotary hammer drill is used for larger jobs.
A variety of drill bits are available for different types of jobs.
Pistol drills are perhaps the most widely used and most versatile of all power tools. Their primary function is to drill holes in steel, wood, concrete, and plastic-in fact, in virtually any material used in building.
Click on each term to know more:
Chuck is the mechanism at the end of the drill motor. Chucks usually contain three jaws that open and close simultaneously to release or grip a drill bit or other accessory.
Each drill motor has a maximum no-load rating, which is stated in rpm. “No-load” means the pistol drill is not doing any actual drilling and the motor is running freely at its maximum speed.
No-load ratings vary depending on the drill’s capacity. On all drills, as drill capacities increase, drill speeds decrease. Simply stated, larger drill bits turn more slowly.
Drill Capacity and Drill Speed
The reason an increase in drill capacity means a decrease in drill speed is that, as drill capacity increases, so does the drill's torque. (Torque is a measure of a tools ability to do work.) Therefore, larger-capacity drill motors will turn more slowly than smaller-capacity motors.
Variable-speed drills can operate in a wide range of rotational speeds, from slightly above zero to the maximum speed of the drill's motor.
The pressure applied to the drill's trigger determines the rotational speed: the more pressure, the higher the speed.
Manufacturers realize that drilling applications are not standard and that different applications require different speeds.
Cordless drills are becoming more popular because of their versatility and convenience over the traditional portable drill.
A cordless drill is especially useful when working in areas where a power source is difficult to find or where it would be awkward or hazardous to run an electrical cord.
Drill bits are the cutting tools used in electric drills, traditional and cordless alike.
Drill bits are mounted in the drill chuck cavity and then locked into place.
There are several different types of drill bits: twist, spade, hole-saw, self-feeding, auger, and masonry. Each is shaped differently, and has special properties or special uses.
Types of Drill Bits
Click on each type of drill bit to know more:
The twist bit is a versatile drill bit that can be used to drill into almost any material. Twist bits are most commonly used for drilling small holes before installing plumbing fixtures.
The spade is flat, and the sharp tip acts as a guide, centering the hole. Most of the drilling is done by the honed cutting edge at the shoulders of the spade.
Spade bits cut fast and are long enough to drill through fairly thick work pieces. These bits are designed to cut wood and some plastics.
The hole-saw bit has saw-like teeth arranged around a hollow cylinder at the end of the bit. This blade is attached to a shaft, which is inserted into the drill chuck like the shaft of any other drill bit. As the drill turns the bit, the teeth on the blade cut through the material.
Self-feed bits, or multi-spur bits, bore holes in wood quickly. They are good for drilling through floor joists and wall studs and for drilling in hard-to-reach areas because you do not need to move the drill to bore the hole.
Auger bits are designed to cut only wood. Do not use them to cut metal; it will damage the bit.
A masonry bit has a carbide tip that allows for easy drilling through masonry materials, such as concrete, brick, stone, and plaster. These bits are designed only for masonry.