As the name would suggest, these are drill bits that are made wholly of carbide. So it is not merely steel coated with carbide, nor an adjoining of steel and carbide (as in brazed carbide drill bits). Due to their stiffness, solid carbide drill bits have some of the lowest tolerances among carbide drills, and hence drills in general. However they do tend to be brittle, which means they are at risk of breaking if some flexibility is required of the bit, such as on lathes.

These drill bits happen to be the most expensive among the various kinds of carbide drills. Nevertheless, this is what might be required, or it might very well be that it is more feasible to go with the more expensive option. For eg. Printed circuit boards (PCBs) require many (as in hundreds or even thousands of) small holes. But because these circuit boards tend to be made of a very abrasive kind of fiberglass, steel drills do not fare very well, as they will quickly wear down. Solid tungsten carbide drill twist bits, though more expensive than the steel counterparts, would be the way to go in this case. They are able to bore very fast through the PCBs and do not wear away so easily as the steel bits. In fact, it has been estimated that the solid carbide drill bits can last up to ten times longer than high speed steel bits. They therefore work out to be more economical in the long run, in this scenario.

Solid carbide drills come in a variety of forms and depending on the type, are suited for drilling ferrous or non-ferrous alloys, cast iron, steel, plastics, aluminum, and highly abrasive materials.

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