Drilling down: bits for fine work

1. From left to right: twist, brad-point, three forstner bits, spade, and Vix, with countersink options in the foreground.

Words and photos: David Luckensmeyer

As makers we often settle on tools we already have, but twist drills, spade bits, and dodgy countersinks are not necessarily the best accessories for fine, detailed work. Let’s look at what’s available to consider using on your next project (photo 1).

Brad-point

Brad-points mill clean and accurate holes compared to regular twist drills. The centre point (or ‘brad’) allows a precise hole location when drilling to an awl mark. And the edge spurs at the circumference of these bits provide a sharp hole and significantly reduce tear- out and splintering. I find brad-points are less likely to wander in hard timbers.

2. Pay attention to the business end of your brad-points. The chisel-point (top) is to be avoided. While the other two examples drill nicely, look for knife spurs (bottom) which offer the best and cleanest holes.

Look for brands that have a well-formed centre (some are not fine enough), and avoid brad-points where the point does not extend beyond the spurs (this includes many sets unfortunately). A longer centre is needed to start a hole using a hand drill. Look for Würth Australia Zebra drill bits and Colt brad-points (if you can find them). Both sets are excellent and used often in my shop (photo 2).

Forstner

Spade bits and hole saws (for through holes) are workhorses in the construction industry, but forstner bits are highly desirable wherever precise, flat-bottomed holes are required (e.g. hogging out mortise joint waste).

The same sorts of observations apply as for brad-points: well-formed centres and precisely made spurs are requisites for good performance. Saw tooth bits are a variation of the forstner, and these do not cut as cleanly. It is also best to avoid the carbide varieties – these generally have wider scrapers and smaller spurs optimised for cutting sheet goods. They do not track very well in hardwoods in my experience.

3. The differences between these drill bit styles are obvious, especially the long centring point of the spade bit which can be a problem in thinner stock. Not so obvious is the crenelated edge of the Colt MaxiCut forstner bit which really does aid chip formation and ejection.

For years I used an inexpensive set of forstners and revelled in the improved performance over spade bits. But premium bits cut demonstrably better again – they produce sharper hole edges and clear wood chips more efficiently. Start with a small set like those from Würth or Fisch. The Colt MaxiCut sets are the bees knees but they can be more difficult to find here. They are now shipped into Australia from various sources. I have over twenty bit sizes and use them regularly (photo 3).

Countersink

4. Countersinks designed for timber are often ground with a slight twist or taper (left) which can lead to a non-concentricity between countersink and hole even when using a drill press. In contrast, the Beall (right) creates smooth and centred countersinks.

I’ve never been a fan of countersink bits. They leave tear-out, chatter marks, and often don’t centre perfectly on a hole due to the vagaries of timber grain. I prefer using a large brad-point or a small forstner to install a screw head below the surface. But when you can’t avoid it, countersink bits are indispensable. As you are no doubt aware, there are many brands and types, some specifically for wood and some for diverse materials. I’ve tried dozens over the years, and the one made by Beall Tool Company is my favourite. I’ve ordered directly and it’s a straightforward process. Carbatec offer a countersink made by Veritas which looks similar or identical to the Beall (photo 4).

Long drill bits

Sometimes long screws are needed for furniture construction. I mean screws in the 70–100mm range. How many times have I taken a 4mm twist drill bit and inserted as little as possible into the drill chuck, thereby trying to eek out a little more drilling length? Long drill bits solve this problem. I’m partial to the Sutton long series drill bits, probably because they are widely available and the full metric set has a place on my tool cart.

Self-centring

5. Often referred to as self-centring bits, Vix bits come in different sizes so make sure to buy the sizes you need. For longer screws, simply deepen holes with a conventional twist drill afterwards.

Such drill bits are often called ‘Vix bits’ named after the S.E. Vick Tool Company, but this style of bit with a spring-loaded bit inside a tapered holder is widely available from a variety of toolmakers. These are fantastic bits for hinge installation. One of the better known and well-made versions is by Snappy Tools (photo 5).

This list is by no means exhaustive. The above five categories of bits made the cut for me. You might have selected differently, and chosen to include circle cutters, plug cutters, stepped bits, depth stops, and quick- change bit holders. And you might have referred to a totally different set of brands. Understood. But hopefully there was something here that helped.

David Luckensmeyer is a Brisbane based woodworker and furniture maker, see www.luckensmeyer.com.au and Instagram @luckensmeyer