Which Drill Bit Should I Use?

One of the most common questions we are asked by our customers is which drill bit is the right for their projects. With so many designs and materials it can be confusing to know which is best for your project, so we break down key characteristics below.  

Jobber Bits

Among the most common drill bits, Jobbers are a good all-round drill bit for most projects. They come in a variety of materials and points. “Jobber” refers to the length of the bit.

Tip Style

Split Tip – A split in the tip of the drill bit that allows it to self-center. The split begins to cut before the sharp edges of the drill meet the material. Commonly used along with 135°

Standard Tip – Most common in 118°, a standard tip is perfect for drilling soft materials.

Tip Angle

90 Degree Tip – Relatively uncommon, used on very soft materials like plastic or vinyl.

118 Degree Tip – The most common tip for drill bits, it works well in softer materials like wood, aluminum, thin steel or plastic. They may start to walk when drilling harder steel, and therefore a center-punch should be used to keep the bit on target. Smaller diameter bits under 1/16” are almost always 118°.

135 Degree Tip – Mostly used on hard materials like 410SS or Steel, these bits have a less aggressive tip and center themselves well on harder surfaces. The angle of the tip allows the bit to cut into the material relatively quickly without dulling the tip as on a 118° bit.

Bit Material

In addition to the tip, you should consider the material that the bit is made from.

High-Speed Steel – Most common material great for general purpose use. It is surface treated to ensure a harder material than low-carbon steel. Surface treatment also reduces abrasion and friction between the bit and the material being drilled.

Cobalt – Harder than HSS, these bits are used for drilling steel and stainless-steel and typically are used in conjunction with a 135 Degree Split Point. Cobalt bits are more heat-resistant than steel bits and do not dull as quickly when operated at high temperatures. Keep in mind that any high-temperature usage of a drill bit will eliminate the benefits of heat treating and cause the bit to dull. Lubricating the bit will extend the useful life.

Carbide and Carbide Tipped – Harder material on key points on the bit, good for non-ferrous materials. Carbide in these applications is a combination of either Titanium or Tungsten with Carbon to create an extremely hard, heat resistant material. Tungsten Carbide, for instance, has a hardness on the Mohs Scale of about 9.5 (10 being natural Diamond).

Concrete/Masonry Bits

Masonry drill bits are shaped differently from Jobber bits, and typically have a softer steel body for debris removal with a Tungsten Carbide cutting tip. Masonry bits have larger flutes to allow debris to exit the hole and reduce friction on the bit.

Some masonry bits called SDS Bits are designed to be used in a hammer-drill. These Slotted Drive Shaft bits lock into hammer-drills and are perfect for drilling concrete or brick and are often made entirely from Tungsten Carbide. It is important not to exert too much pressure on an SDS bit as it will reduce the effectiveness of the hammer-drill as the bit both spins and reciprocates in and out of the hammer-drill.

Uneeda Bolt stocks multiple lines of drill bits, both USA Made and imported. If you have any questions on which bit is right for your job give us a call!

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