OTOH, I've seen lots of people turn a drill bit into a screw (or pencil point) trying to 'rotate' it when they sharpen it, by hand or 'drill sharpening' machine.Īll you really need to do (lets assert you can get 135 angle, etc correct). You can ruin a good drill bit by overspeeding and / or not bothering to lubricate. Yes, you get a correct cut IF you have the right feed pressure and right RPM for the bit, type, size, and material being cut. Thank you for ready this how-to on sharpening your own bit! If you see chips come off of the bit on both sides of the drill bit, your good to go! If you see chips only coming off one side of the bit, make sure the two lips are symmetric across the center-line of the drill bit. If drilling is still difficult, look at your chisel and landing angles to make sure you've got enough relief. If you've practiced a little with your bit, and have been able to successfully roll and shape your landing and chisel, you are ready to start drilling! Go ahead and try out your bit in a drill press or hand drill. This almost always leads to uneven lips or will cause you to roll your lip so that it no longer cuts. Always make deliberate cuts, don't try to "feather" a sharp tip by pressing the drill bit lightly into the sander or grinder. But keep on trying! Often rotate which side of the bit you are working on so that you don't favor one side over the other. That's normal and requires a lot of patience. It may take a couple dozen times to get the two lips of the drill bit symmetric. For this reason, it is especially important to create a very small chisel. In fact, while the drill is turning and being forced down into your work-piece, the chisel smears the wood or metal you are drilling into the lips. In truth, this area does no cutting motion. The "chisel" is the line which is created when the landing from both sides of the twist drill intersect. However, too much angle subtracts support from the lip, and will cause the bit to chip more often, especially on the corners. The landing must be angled in such a way that it leaves clearance between the part you are trying to drill and the lip. The "land" or "landing" is what follows the lip and will support the sharp edge while the bit is cutting. This is bad as it makes non-straight holes. If one lip is favored while sharpening, it will become bigger than the other and most of the cutting will be performed on one side of the bit. The two lips on the twist drill should be symmetric if an equal cutting is to be done while drilling. The "lip" is what does the actual cutting. For speed sake, were only worried about 3 basic features on the bit: the lip, land, and chisel. There are many features on a drill bit that can be defined. And you should probably wear safety glasses too. Be mindful and deliberate about where you position yourself on the sharpening device. DO NOT wear gloves as they can actually get caught into the sharpening device and pull you in. WARNING! Your hands will be very close to the sharpening device, and dangerously at risk with losing some skin. So without further adieu, here's what you’ll need: My trainer and I have gotten so good, in fact, that whenever we’re given those cheap HSS China bits (that pretty much everyone has in their garage), we’ll pull them right out of the box and sharpen them before their first use. Now, I’m not saying that after this tutorial, you’ll be able to achieve a perfectly sharp drill bit, but it will get you through the next job until you get enough practice to really put an edge on your cutting tools. So what’s going to be demonstrated here is a kind of lost art-sharpening by hand on a belt sander or bench grinder. In fact, you’ll notice that most of those fixturing devices or machines cost a lot of money, and very rarely do they ever give you something close to a factory sharpen (unless of course you fork out enough to buy an industrial sharpener). When I started my job as a machinist nine years ago, my trainer was skeptical about using any kind of automatic machine or fixture to re-sharpen our drill bits. Well before you head over to the hardware store to buy yourself a brand new box of drill bits, try this simple technique first and save yourself a lot of time and money!įollow these steps and you can transform your used, dull, chipped, broken, or otherwise useless drill bit, into a prime hole blasting instrument. Have you tried to drill something recently and noticed your bits aren't cutting like they used to? Maybe some of your bits are so bad, you can't even get through wood or soft metals anymore without creating a plume of smoke and high shrieking squeaks.
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