A jobber drill is so named because it was originally designed to serve as an all-purpose drill bit for machinists and toolmakers to drill a variety of different materials and size holes in different applications.
The jobber drill bit was designed to handle a heavier workload than the standard twist drill, which is usually used in light-duty drilling applications. Jobber drills are shorter and sturdier than twist drills, and their shorter length allows them to perform a larger number of jobs in a limited amount of space.
The cutting edges of jobber drills are ground with a specific cutting angle to prevent material from binding while the bit is being used. Jobber drills are available in a wide variety of sizes and shapes to suit a variety of drilling needs.
And because of their versatility and durability, jobber drills have become an essential tool in many machinist and toolmaker workshops.
When would you use a jobber drill bit?
A jobber drill bit is a type of drill bit typically used for general purpose drilling applications in a variety of materials. It is also known as a Twist Drill bit, since the cutting edges are twisted like a screw thread.
Jobber drill bits are primarily used in machines such as drill presses, handheld drills, and screw guns. They are the most common type of drill bits used for general purpose drilling in materials such as wood, plastic, aluminum, and mild steel.
Jobber drill bits are generally used over short distances, in thicker materials or in harder alloys, and are intended to be used in smaller handheld drills or drill presses. For example, they are commonly used to drill holes in wood or plastic for plumbing fixtures, such as faucets, or to route electrical wiring.
They are also frequently used for manual tasks, like making pilot holes for screws in wood, or for drilling into walls.
What is the difference between jobber length and mechanics drill bits?
Jobber length drill bits are the most commonly used and versatile of the various types of drill bits. They are usually six to eight inches long and feature a short, sharply tapered point and a spiral flute that removes the material as the bit is twisted in the hole.
They are designed for a wide range of applications, from drilling small holes in wood to larger holes in metal. Jobber length drill bits come in a variety of sizes, from small diameter bits all the way up to larger diameter bits, as well as in a variety of coatings to extend their life.
Mechanics drill bits are similar to jobber length drill bits, but are generally shorter and feature a steeper taper than jobber length drill bits. They are specifically designed for drilling and machining metals and other hard materials, and tend to be much sturdier and less prone to breakage.
Mechanics drill bits come in a variety of sizes, from small diameter bits all the way up to much larger diameter bits, as well as in a variety of coatings to extend their life. They are mainly intended for use in manufacturing, industrial and professional applications, rather than in home improvement or DIY projects.
How long are jobber length drills?
Jobber length drills are typically about six inches long. However, the exact length varies depending on the specific jobber drill bit. Some jobber length drills may be shorter or longer than this, depending on the individual bit or the size of the drilled hole required.
On average, jobber length drills are most commonly found ranging in length from four inches to nine inches.
What are the 5 types of drill bits?
The five most common types of drill bits are twist drill bits, masonry drill bits, brad-point drill bits, spade drill bits and countersink drill bits.
Twist drill bits are the most common type and come in a variety of sizes and materials. They are designed for standard woodworking, metalworking, and plastic drilling applications. They are commonly made of high speed steel and feature a point with two cutting edges and a shaft with spiral flutes.
The twist action of the flutes helps to clear debris as the hole is drilled.
Masonry drill bits are specifically designed to drill into brick, concrete, and other masonry materials. They feature a special carbide tip that is much harder than high speed steel, which helps to absorb the shock and prevent the bit from breaking or becoming dull.
Brad-point drill bits are designed to create extremely precise holes in wood. Unlike twist drill bits, they feature a point with two cutting spurs that help create a cleaner entry hole and a smooth exit hole.
Spade drill bits are also designed for drilling into wood. They feature a large paddle shaped bit tip designed for rapid material removal. They are ideal for creating large holes in soft wood materials.
Countersink drill bits are designed for creating tapered holes in wood. They feature a pointed tip and fluting near the base of the bit. The tapered shape of the hole allows room for a flat head screw to sit flush with the material once it is inserted.
How do I drill a hole in wood without splitting?
To drill a hole in wood without splitting it, you will need to take several steps to ensure that the hole is properly drilled. First, it is important to use a drill not powered by a power tool, such as a hand-held drill or an old-fashioned brace and bit.
This will allow you to more easily control the angle and pressure of the drill bit as it enters the wood, which will help to prevent splitting.
Second, before you drill the hole, you should use a nail or awl to make a small indentation in the wood where you will be drilling. This will help to guide the bit and keep it from wandering, which can cause the wood to split.
Be sure to use a bit with a sharp, pointed tip, as a duller or blunter bit can put too much pressure on the wood and cause splitting.
Third, as you drill, make sure to apply even pressure and keep the bit level with the wood. Too much pressure can cause the leading edge of the bit to dig too deep into the wood, creating excess friction that can lead to splitting.
Also, make sure to periodically pull the bit out of the hole to remove any sawdust that might have accumulated, which can also cause friction and splitting.
Finally, when the hole has been drilled, rub the area around the hole with some wood wax or lubricant to smooth the edges and reduce the risk of splitting. The wax or lubricant also helps to protect the wood from cracking, ensuring a clean and neat finish.
following these steps will help to ensure that the hole is drilled accurately and without any splitting.
Why are they called aircraft drill bits?
Aircraft drill bits are called such because they are used to make holes in thin material, such as that found in aircraft. Holes made with aircraft drill bits need to be accurately sized, as any deviation can cause structural weakness and reduced aerodynamic performance.
Aircraft drill bits are made with a special stepped design that reduces the cutting area, resulting in less friction and heat. They also have sharper points, allowing them to create smoother, more precise holes than other types of drill bits.
Additionally, the cobalt and vanadium in aircraft drill bits helps with increased durability and toughness when drilling through hard materials.
What are short drill bits called?
Short drill bits are typically referred to as twist or screw bits, or auger bits, depending on their specific design. They come in a variety of sizes, include standard twist bits, Brad- and cleco-point bits, and masonry bits.
Twist bits are the most commonly used type of short drill bit and are designed to be used with a hand-held electric or battery-powered drill driver. They have a cylindrical body with a pointed, tapered tip at the end designed to cut through metal, wood, plastic, and other materials.
Brad- and cleco-point bits are specialized twist bits used to drill precise holes in metal without creating burrs or debris. Masonry bits are designed for drilling concrete and other masonry materials, and feature a hardened steel tip for greater durability.
What does jobber length drill bit mean?
Jobber length drill bits are the most common type of drill bit and are named for their primary purpose—to drill out holes in the job, or workpiece. These drill bits are designed for use on a variety of materials and are used for general purpose drilling.
They are usually about six inches long, with two or three cutting edges at the tip and a twist at the base. The twist gives the bit its name, which refers to the jobber that is responsible for the cutting of the hole.
Jobber length bits are ideal for drilling holes in most materials including wood, plastics, metals, and composites. These types of drill bits are also available in different sizes and configurations, making them versatile enough to handle a wide range of drilling applications.
What are mechanics length drill bits?
Mechanics length drill bits are typically shorter than jobber length drill bits and longer than screw machine length drill bits. They are widely used for general purpose drilling in a variety of materials due to their wide range of sizes and high durability.
Mechanics length drill bits are typically used with portable and production line drilling machines and offer greater rigidity and an optimized flute angle for greater chip clearance. These bits are made from high speed steel and feature a black and gold finish for improved lubricity.
Mechanics length drill bits feature a 135° split point tip for increased material penetration and fast, accurate starts, and their overall length considerably reduces their vulnerability to drill breakage and deflection.
How is drill bit length measured?
The length of a drill bit is measured from the tip of the bit to the back of the shank. Generally, for standard twist drills, this is the same as the overall length. However, some specialty bits, such as split point, jobber, and cobalt bits, have a longer shank length than their overall length.
In these cases, the overall length includes the additional shank length. To measure the drill bit accurately, it is important to ensure that the measurements are taken from the exact same points each time, usually the back of the shank and then the tip.
Also, measurements should be taken in decimal fractions of an inch, rather than fractions of an inch, as this gives a much more precise measurement.
Do drill bits come in different lengths?
Yes, drill bits come in a variety of different lengths. The length of the bit is determined by the purpose and the material it is being used to drill through. Smaller bits, for instance, are used for drilling through softer materials such as plastic or wood and are shorter in length.
Longer bits are necessary for drilling through harder materials because the fluting of the bit must be longer to reduce the load and pressure so that it can efficiently cut through the material. The length can also be determined by the type of project and the space constraints depending on the application.
For instance, if the job calls for drilling more precise and shallow holes, then a shorter drill bit may be used.