Drill Bits - The Different Types Explained - different kinds of drill bits
I tested a variety of Forstner bits; some had wavy teeth around the rim, while others had straight teeth or simply a sharp bevel. The performance differences I noticed were slight, with mid-priced Forstners performing as well as more expensive versions. To get the most for your money, buy a set of Forstner bits instead of acquiring them individually.
Anatomical details vary greatly when you move from one big bit type to another. So it’s not surprising that there are differences in cost and performance. By considering the following factors, you can make sure that you get the results you’re after, and that you’re not using an expensive bit to do work that a more affordable bit can tackle effectively.
You’ll need a drill press to use this tool safely, but for holes larger than a Forstner can manage, you can’t beat a circle cutter. Infinitely adjustable for diameters up to 6", this big-hole specialist replaces a pile of expensive holesaws, for example, and cuts cleaner, smoother holes in the bargain. Use it to cut snug-fitting openings for vac hoses in shopmade jigs, fences, etc. As a bonus, you can invert the cutter to create toy wheels and other perfect disks. The cutter is also very easy to sharpen. To use a circle cutter safely, choose a low speed on your drill press, clamp down the work, keep your fingers clear, and feed the tool slow and steady. You’ll be amazed at the results.
I used the 1/8 x 1" compression bit for cutting 3/4 inch hardwood for wooden toys on my cnc. These bits outcut most of my other 1/8" bits by far with less heat problems and slippage in the chuck. I will order more when needed for sure. Great bits
These five types of big bits look very different from each other, and perform differently as a result. This chart gives you their basic capabilities at a glance, but be sure to read the full write-ups that follow for all the important details. Price ranges are for individual bits.
A holesaw won’t cut as cleanly as a circle cutter, but it can make holes just as big. You can use these bits in a handheld drill, but make it a powerful one. These hefty bits demand high torque and a firm grip. In my tests, I found that holesaws with fewer teeth—and long slots ahead of those teeth to eject chips—cut worlds better than those with continuous teeth around the rim. Like circle-cutters, holesaws can only drill through holes, in materials up to about 2" thick. If you don’t own a drill press, or you are facing a remodeling job that requires big holes in construction lumber, a holesaw is right for you. Holesaws equipped with “bi-metal” or carbide teeth can also drill through thin metal.
A contractor’s favorite, spade bits offer the least expensive path to moderately large holes, and they work in handheld drills and drill presses alike. Although they’re designed to bore quickly through soft construction lumber, they drilled surprisingly clean holes in hardwoods in my tests. But the paddle-shaped design makes spade bits prone to vibration and rough cuts when they get dull, which they do relatively quickly. Also, while they can drill flat-bottomed holes, the long center tip leaves a deep, narrow hole on the middle. For all these reasons, buy spade bits in a pinch, but get a set of Forstners when you can afford them.
Contrary to popular wisdom, Forstner bits can be used with handheld drills, but be sure to go in straight and square and start with a light touch. Forstner bits can bore deep holes, but you’ll need to withdraw the bit frequently to clear chips and help prevent overheating. The same geometry that cuts clean-sided holes puts a lot of steel in contact with wood, producing extra friction. If your bits will be subjected to heavy use, consider spending the extra money for carbide Forstners that can take the heat without getting dull.
To solve the big bit puzzle, I ordered a bunch of plus-sized bits and collected plenty of wood to use for various drilling assignments. You’ll find plenty of helpful information in the chart on the facing page, and in the write-ups that follow. With these details, you’ll be able to match the bit to the job and get the best value from every bit of money you spend on these tools.
For many reasons, I consider a set of Forstner bits to be a must-have in any woodworking shop. Although there are slight differences in Forstner bits made by different manufacturers, the basic cutting geometry features a precisely machined rim, a center spur, and a chipper. These cutting elements work together to produce tearout-free, flat-bottomed holes in any type of wood. What’s more, Forstner bits can bore straight, angled, or overlapping holes. You can even bore a partial hole on the edge of a board, as shown in the photo at left. Count on these bits for perfect counterbores, smooth dog holes, decorative cutouts, and round recesses of all kinds—and for clearing the waste out of mortises without wandering.
With a lead screw that keeps them on track and pulls them through the wood, plus deep flutes for ejecting chips efficiently, auger bits drill deep, smooth holes, even if you enter the wood at an angle. The lead screw forces a feed rate that works well in softwoods, letting contractors bore big holes through a stack of studs at once, for plumbing and electrical components. But that aggressive feed rate can be a problem in hardwoods, causing auger bits to jam in a drill press or cordless drill. Put them in a hand-powered brace, however, and they are a chairmaking champion, boring round mortises in square or round legs, at any angle.
This is an investment! That being said, if you only doing one slab, I would recommend DIY build or having someone professionally flatten your project. I would hazard a guess that you would be saving for a fifth of the cost of this rig. I bought the dust shield with vacuum hose attachment and was disappointed on a few levels. Firstly, it's a gimmick that falls short of its intended purpose and although it may cut down a little of the waste being scattered in the shop, it does not work as advertised. Do your slab flattening outside or you'llbe vacuuming for days. Secondly the hose port fit is not standard for any shop vac, so you'll be needing some type of adapter. As for the router sled itself, the build is sturdy, and it does work as intended. However there is the minimal clearance issue. Even at its lowest setting, I still had to raise the work piece as the plunge depth of routers are limited. Also expect to clear debris (constantly) from wheel path as it collects and will hinder the smoorh and level tracking of the wheels Overall, it works. But I'm thinking I should have opted for the bearing rail system. I gave it 3 stars because that's where it falls in the overall rating. Average! These are my opinions from my experience. Your millage may vary. If I could send it back without the hassle. I probably would. I don't have the box, and the return policy says everything has to be in original unused condition, which is impossible after use.
I am making wooden toys for great grand kids and needed bits for my cnc to cut 1/4" cherry for some of the parts . Your 1/8 x 3/4 compression bit worked like cutting butter. Nice bits, will purchase more when needed.
In any workshop or homeowner’s toolbox, you’re sure to find a good selection of small bits—a set of standard twist drills and, if you’re lucky, a full set of brad-point bits also. But that bit kit tends to peter out when you get to larger diameters, let’s say ¾" or greater. There are plenty of tasks that require big bits (sidebar, right), but it’s not always easy to choose the bit you need, because of the bewildering array of types available.
Stopped holes, sort of. A spade bit can drill a stopped hole, but the long center spur leaves a deep, narrow hole in the middle.