“Jobber bits” is undoubtedly a hilarious name. However, as funny as the name may be, jobber bits are very common pieces of equipment. Jobber-length drills are the most common type of drill available today, and chances are pretty good that you’re going to run into jobber bits at some point while working in the field.
Today, we’re going to explain the most important characteristics of jobber bits and how you can be sure to choose the best jobber bits for any type of task.
The first question many people have about jobber bits is, “where does that name come from?” The word ‘jobber’ has actually been used to refer to dozens of different things throughout history, although the general definition is “something that does a job.”
Today, jobber bit refers to the length of the drill itself. Specifically, jobber bits have a flute length between 9 and 14 times the diameter of the drill. A ½ inch diameter jobber drill will be able to drill a hole 4 ½ inches deep because it is 9 times the diameter in length, for example.
Basically, jobber bits are the most common type of drill size available today and the term is used to generally refer to drills that are between 9 to 14 times the diameter in length. Some specifications place the jobber bit size between 8 to 12 times the diameter of the drill, while other specifications place it between 9 to 14 times.
Jobber bits are measured using a number of different measurement systems, and it’s easy to get confused between the types of systems in place:
Fractional bit sizes: Fractional bit sizes, as the name suggests, use a fractional measurement system to measure jobber bit. Sizes are measured in increments of 1/64 inch up to 1 inch, 1/16 increments inch to 3 inches, 1/8 inch increments to 3 ¼ inch, and ¼ inch increments to 3 ½ inches.
Number and letter sizes: Sizes are measured according to numbers and letters. Numbers range from size 1 through size 80 as well as sizes A through Z.
Wire sizes: The wire size measurement system starts at size 1 and increases by whole numbers to an undefined limit.
Metric: The metric measurement system for jobber bits uses the standard metric system
The measurement system and drill size you choose will vary according to your application. If you need a shorter and more durable drill for a job, then you’ll want a mechanics length or screw machine length designation. Or, if you’re drilling a deeper hole through softer material, you can rely on fractional bit sizes and metric measurements to find the drill bit you need.
Ram Products has a wide selection of jobber bits available to order:
–Heavy Duty Black Gold Jobber Bits can be found here. Heavy Duty Black Gold jobber bits function in much the same way as heavy duty jobber bits although they’re coated with a black and gold lining that is specially designed to hold lubricant for smoother drilling.
–Cobalt Jobber Bits can be found here. All cobalt jobber bits are classified as heavy duty and work best in cast-iron, low and medium carbon steel, high alloy steel, and stainless steel.
That’s it! With the information listed above, you should have no problem finding the right jobber bits for the task at hand.