Every tradesman and serious DIY-er will appreciate having the right tool exactly when it’s needed. With so many different tools around in as many applications, even the smallest differences can mean if the job is done quickly, safely and to a professional standard, or not at all. Of course, a universal toolkit can be versatile across more jobs, but probably not quite enough for the task at hand. That’s why there’s so much variety.

Specialised tools are nothing new, though the trend for providing the right tool for the growing number of different jobs is on the rise. When buying drills bits, there’s so much to take in. The material that you’re drilling into, the depth and diameter of the hole, the required finish, drill and bit compatibility, speed and ease of use, and so many other factors. This leads to there being dozens of different drill bits, each suitable for a different task.

What are Step Drill Bits?

Unlike most drill bits that retain the same diameter along the whole length, step drill bits are conical in shape, with pointed tips that gradually increase in thickness. This is done in ‘steps’, with each step slightly wider than the one before it. This makes step drill bits both a highly specialised and at the same time versatile tool. One bit can be used to drill holes in different widths, and in different depths, effectively replacing a whole set of drill bits to get wider or narrower holes.

Where are Step Drill Bits Used?

Step drill bits are handy for different jobs. They’re used to drill holes in various materials, mainly sheet metal, but are also good for wood, plasterboard, tiles, or even ceramics. Builders, metal workers, carpenters, electricians, plumbers all own a set of step drill bits. They are used to slowly shave off materials and enlarge holes from one step to another. The design allows for nice, clean finishes, making step drill bits the ideal tool for deburring and cleaning.

In terms of compatibility, they fit both to handheld or bench drills, so can be used for smaller projects where portability is important or large-scale jobs with larger pieces of materials. Different materials used in the construction of step bits are suited for drilling into particular surfaces and substrates. Those designed for softer materials differ from those meant for drilling into hard metals or ceramics. Something to consider when buying.

Step Drill Bits Design

Step drill bits look like inverted ice cream cones. The tips are set at an angle so that they easily pierce into the material being drilled with the minimal force needed to make the initial tap. Two profiles of grooves or flutes extend from the tip down to the last step. These grooves have cutting edges that are designed to both drill and deburr the material. The last step thins out into a shank that is fitted into the drill chuck.

Two basic designs are used. The grooves can be formed into a spiral or are straight, meaning there are straight and spiralled step drill bits. Spiralled bits tend to work quicker, removing more material at a time. This though also depends on the materials of which the drill bits are made.

In terms of sizing, there are step drill bits in wider and thinner profiles. Widths range from a minute 0.1mm to over 10mm depending on what you’re drilling. There are engraved markings on each step to denote the width. Also, there are different lengths to reach the desired depth. Most step drill bits have 9 steps, but you can also find variants with up to 12 steps.

Materials in Step Drill Bits

High-speed steel, also known as HSS is one of the most common materials used across different drill bits. In step drill bits, it is also one of the cheapest, considering what else is available. HSS drill bits are good for drilling and deburring in softer materials, like plywood, softer natural woods, or plastics. They can heat up quite quickly, so you’ll be using drill bit fluid often. For quicker drilling and for harder surfaces, like steel, iron, bronze and aluminium, consider Cobalt step drill bits.

These won’t overheat and can be used at higher drilling speeds. One step further up is Titanium, which is less brittle than cobalt coated drill bits and shows less wear and they are good for frequent professional use. The toughest step drill bits are made of carbide, a composite alloy of carbon and natural metals. Mostly tungsten is used. These are good for drilling into masonry, tiles and thermoplastics and are also the most expensive.

Buying and Using Step Drill Bits

Step drill bits can be used with various rotary drills. Most have auto tips, that make dents into the materials drilled. Bits with thicker tips may need initial dents to catch on before they’re used. To make the desired hole, first bits in smaller diameters are used, then the hole is widened to the desired size with a bit with wider steps. Periodic use of fluid is recommended to avoid overheating.

Step drill bits are sold as separate units or are packaged in different sizes, generally three or more handy toolboxes. They’re sold at most well-stocked hardware stores. Consider which materials you mostly use in your line of work, and purchase step drill bits in the appropriate material and size.