Jobber Drill Bit: Uses, Sizes
What Is a Jobber Drill Bit?
Jobber Length drill bit is a general-purpose twist drill bit with a straight shank. The term jobber length refers to flute length (which is the length of the twisted part of the drill bit). The flute length of a jobber bit can go from 8 to 14 times the diameter of the bit.
For example, if a jobber-length drill bit has a diameter of ¼″, its length would be 2 ¾ inches which is 11 times the diameter.
Jobber Bit Uses
Jobber-lengths are excellent for general purpose applications since they can handle a wide variety of jobs. They usually come with a point angle of 118° or 135°. Jobber bits can be used for drilling wood and metal and they are very versatile.
Why is it Called a Jobber Bit?
What is the actual meaning of jobber bit? Let me take you on a short trip down history lane.
The term Jobber was most commonly used from 1850 to 1950. It refers to the middleman between manufacturers and retailers (any person or company that buys from the manufacturers and sells to retailers).
What does that have to do with drill bits, you ask?
Well, during that period, manufacturers used to sell general-purpose drill bits that aren’t designed for specific purposes like today. These bits were of medium length, making them suitable for a wide variety of applications. A “jack of all trades, master of none”, if you may. Such drill bits were called “jobber bits”. In other words, a jobber drill bit was what’s known today as a “general-purpose” bit.
As time passed and drill bits got more specialized, jobbers started to lose their charm as the only kid on the block (they are still the most commonly used bits, though). Today, the term “jobber” refers to the bit’s length rather than its purpose.
Jobber Drill Bit Size Chart
Different systems are used to measure these drill bits, including letter sizes, fractional sizes, wire gauge sizes, and metric sizes. Here’s a table that explains the flute length and overall length of a jobber drill bit using fractional sizes:
Post time: Oct-20-2023
