Drill Bit Set questions answered
Updated June 2026Independently researchedNo paid placement.
The best drill bit set for you depends almost entirely on what you plan to drill into. For general home repair, a set of high-speed steel bits with a 135-degree split point and a titanium coating covers most wood, plastic, and soft-metal jobs. Masonry bits and step bits are specialty additions, not everyday essentials.
What types of drill bits should I buy for general home use?
For everyday tasks like hanging shelves, assembling furniture, or light electrical work, a set of twist bits made from high-speed steel (HSS) is your best starting point. Look for bits with a 135-degree split point; they self-center and reduce the walking that can mar your surface. A titanium nitride coating adds hardness and reduces heat, helping the bits stay sharp longer through wood and mild steel. If you occasionally drill into concrete or brick, you will also want a small set of masonry bits with carbide tips. For larger holes in wood (say, for running cables), a spade bit or a hole saw is more practical than trying to hog out material with a twist bit. Don’t feel you need a 100-piece set right away; a focused set of 10 to 20 common sizes will serve you better than a jumble of rarely used oddments.
How do I choose the right drill bit size?
Drill bit sizes are marked on the shank in fractions of an inch (e.g., 1/8-inch) or metric millimeters. When you need to match a screw, the general rule is to use a bit that is slightly smaller than the screw’s inner body (the shank) but the same size as the screw’s outer diameter if you are creating a clearance hole. Many good sets include a chart or index that shows recommended pilot-hole sizes for common screw gauges. For anchoring in drywall or concrete, the anchor manufacturer typically specifies the exact bit size. If you are drilling for a cable or pipe, measure the outside diameter of what you are passing through and choose a bit that is about 1/16-inch larger to give yourself some play. A simple trick: keep a cheap plastic caliper or a gauge card in your toolbox to verify sizes before drilling.
Can I use drill bits for metal and wood interchangeably?
Yes, a quality HSS twist bit will drill into both softwood and mild steel, but there are important caveats. Wood dulls bits much less aggressively than metal, so a bit that works fine for wood may feel disappointingly sluggish in steel. When you switch to metal, you need to go slower (lower RPM) and use firm, steady pressure; trying to rush or spin fast will overheat the tip and ruin the temper. If you regularly drill into tough metals like stainless steel or high-carbon steel, you should invest in bits designed for those materials, such as cobalt-alloy bits. And never use wood bits (like brad-point or auger bits) on metal, they are ground at a different angle and can grab or chip. A good compromise for home use is a set of mixed-purpose bits with a split point and a coating; just be prepared to drill metal in several light passes, clearing chips often.
What does a good drill bit set include? (materials, coatings)
A truly useful set covers the sizes you reach for most: 1/16, 5/64, 3/32, 7/64, 1/8, 5/32, 3/16, 7/32, 1/4, and 5/16 inches in twist bits. Many sets also add 3/8 and 1/2 inch bits, though those can be costly and are not needed for most jobs. The case matters: a clear, indexed box with labeled spots makes it quick to find the right size and to notice when a bit is missing. Look for sets that list their steel grade plainly, standard HSS is fine for occasional use; M2 (a common high-speed steel) is a step up. Coatings like titanium nitride (gold-colored) and black oxide (black) each reduce friction and corrosion. Black oxide bits are slightly more brittle but good for metal; titanium bits run cooler in wood and plastic. Avoid cheap “black-coated” bits that are just painted, they dull fast and shed the coating.
How should I care for my drill bits to extend their life?
The two biggest enemies of drill bits are heat and moisture. Always clear chips frequently, backing out of the hole clears the flutes and allows air to cool the bit. When drilling metal or thick plastic, use a lubricant (a few drops of household oil or a dedicated cutting fluid) to keep temperatures down. Never let the bit smoke; that means you are creating enough heat to soften the steel. After use, wipe bits clean with a dry rag and store them in a closed case or roll, not loose in a toolbox where they can clatter against each other. If you ever notice a bit won’t cut cleanly or requires extreme pressure, it is likely dull; many bits can be sharpened with a bench grinder or a sharpening jig, but small bits under 1/8 inch are usually not worth the effort. Replace them.
Are expensive drill bit sets worth the extra cost?
They can be, if you drill often or into hard materials. Bits made from M42 cobalt or solid carbide cost significantly more than HSS, but they hold an edge many times longer in stainless steel, cast iron, and abrasive composites. The fit and finish are also better: the cutting geometry is precise, the tip is concentric, and the coating is applied uniformly, which means cleaner holes and less breakage. For the casual homeowner who drills into drywall, softwood, and the occasional plastic anchor, a moderately priced titanium-coated HSS set, in the range of a few tens of dollars, will last years. The premium sets really shine for tradespeople or serious hobbyists working with sheet metal, thick aluminum, or rebar. The honest truth: the best drill bit set is the one you will actually use, so match your investment to your projects.
Frequently asked questions
What is the difference between high-speed steel and carbide bits?
High-speed steel (HSS) is tough, resists chipping, and can be sharpened easily. Carbide is much harder and stays sharp far longer, but it is brittle and can shatter if misused. For general wood and mild steel, HSS is fine; for tile, glass, and hardened metals, carbide-tipped or solid carbide bits are the better choice.
How do I drill into tile or glass without cracking?
Use a carbide-tipped masonry bit or a diamond-tipped bit. Start with a low speed and very light pressure; score a small divot first to prevent the bit from wandering. Never use a hammer drill action on tile or glass, a smooth rotary action is essential. Keep the area wet with a spray bottle or a constant drip of water to reduce heat and friction.
Why do my bits keep breaking or dulling quickly?
Most likely you are using too high a speed or too little pressure. For metal, run your drill at a slower speed and apply firm, steady pressure so the bit cuts metal rather than rubbing it. Also check that your bit is sharp, a dull bit forces you to push harder, which leads to overheating and breakage. Using the wrong bit type for the material is another common cause.
Can I sharpen drill bits at home?
Yes, with a bench grinder and a bit sharpening jig or even a specialized drill sharpener attachment. The key is to maintain the original point angle (usually 118 or 135 degrees) and to keep the cutting edges symmetrical. For small bits under 1/8 inch, it is usually more economical to replace them than to attempt sharpening.
What is the best drill bit for hardened steel?
For hardened steel, look for bits made from cobalt high-speed steel (often labeled M35 or M42) or solid carbide. Cobalt bits resist the heat generated by drilling hard materials better than standard HSS. A 135-degree split point is also helpful to reduce walking. Go very slow, under 1,000 RPM for smaller bits, and use cutting oil every few seconds.
Should I use a lubricant when drilling metal?
Absolutely. Lubricant (even a few drops of household oil or WD-40) reduces friction, carries away heat, and helps the chips clear from the flutes. It can double the life of your bit and result in a cleaner hole. For vertical or overhead drilling, a thick cutting paste or wax works better than liquid oil because it stays in place.