Perhaps for most of us, when drilling a hole we are focussed not so much on the hole but the end use, somewhere to stick a screw or bolt so we can attach a shelf, light fitting or art work to a wall. However for many craftspeople, artisans and joiners and fine furniture makers this is not enough. They need an arsenal of precise, specialised bits of which the adjustable wood bit is one.
Its what it says on the tin lid
An adjustable wood drill bit, is and does what its name suggests. It is a bit that can be adjusted or resized to create holes of many different sizes. Sort of a many bits in one tool.
At its cutting point it has s small, sharp incisor or starter that first bites into the wood to give the bit a grip. If you have ever tried to drill a large whole with a big bit you will be familiar with the problems of “bit wander.” So the needle like point of an adjustable wood bit helps overcome this and ensures a true hole.
Above this needle point comes the secondary cutting blade, the adjustable section. This part of the bit is secured by a thumb screw, loosen it to adjust the blade to the required size of the hole and, obviously, tighten it to secure it in place. When that job is finished the adjustment process can be reversed and repeated to set the bit to drill another diameter of hole. Because accuracy is extremely important at this level of boring, the adjustable wood bit comes with a size scale printed on the adjustable blade, This ensures the precision of the hole.
Set it your way
Usually, drill sizes are standard, so, fortunately are screws and bolts so it is unlikely that most of us would ever need a hole out of the norm. Besides, thee is a vast array of sizes available on the HS [high speed] drill market. But in precision wood work, required hole sizes may not always be international standards The adjustable wood bit allows the craft person almost infinite control to set and bore holes that suit his or her exact needs. This flexibility of size control also means there is not the same selection of adjustable wood bits on the market.
Artist and craftspeople generally tend to invest greater time in their product and often prefer to sue hand tools over power ones so adjustable wood bits are created with the hand drill [or brace] in mind with a variety of shanks. However, there are also those designed for use with low power electric drills which opens up their use for home handy people or casual hobbyists. However, do bear in mind these are NOT high speed drills so, if possible, dial back the speed on your electric drill, otherwise not only will you possibly “burn” the wood but the heat generated will kill your adjustable wood bit. If you intend to do a lot of wood working, maybe think about investing in a hand brace and let your artistic genus and workmanship shine through~