Best Drill Bits: The Ultimate Guide to Choosing and Using
When it comes to drilling, having the right drill bit makes all the difference in getting holes precisely and efficiently. With the wide variety of drill bits available, selecting the optimal type and brand for your project materials can ensure success. This collection of Tonix Tools will overview the major drill bit types, and top features to consider and provide the best drill bit set recommendations for commonly drilled materials.
What is a Drill?
A drill is a tool used to create cylindrical holes in a workpiece. The main components of a drill include:
- Drill bit - The cutting tool that bores the hole. Drill bits come in many materials and designs for different applications. Common types include twist bits, spade bits, auger bits, masonry bits, etc.
- Chuck - The part that grips and spins the drill bit. Chucks can be keyless for quick bit changes or keyed for heavier tasks.
- Motor - Provides power to turn the chuck and drill bit. Motors are typically electric or pneumatic. Higher power allows faster drilling.
- Drill press - Stationary style drills where the workpiece is moved into the spinning bit. Offers control and accuracy.
- Handheld drill - Portable drills for mobility and use in tight spaces. Runoff batteries or a power cord.
The rotating action of the drill bit cuts a circular hole into materials such as wood drill bits, plastic, metal, concrete, and more. Drills are essential power tools for DIY, construction, manufacturing, and other hole-boring applications. Features like variable speed, hammer function, and reversible direction make drills highly versatile. Proper drill bit selection and use is key for efficient, safe, and quality hole drilling.
Structure of Drill Bit
The intricate structure of a drill bit is engineered to efficiently bore holes in various materials. Each component serves a specific purpose.
The Point Angle
The point angle determines how aggressively the tip of the drill bit will attack the workpiece. Wider point angles exceeding 130 degrees are best suited for drilling in soft materials like wood, plastic, and light metals. The wide drill bit angled tip easily slices into the material. Narrower point angles between 90-120 degrees work better for hard, dense materials. The sharper point concentrates force onto a smaller area to penetrate tough materials like hardened steel. Standard twist drill bits usually have a 118 degree point angle for versatility across many materials.
The Cutting Lips
The cutting lips are the sharpened edges at the tip of the diamond drill bit that carve out the circular hole. As the drill bit rotates, these lips scrape and gouge the material to cut away small pieces and form the desired hole. The cutting lips must be extremely hard and sharp to bite into the workpiece, whether it's hardened steel, wood, plastic, or other materials. They take the brunt of the mechanical wear during drilling, so the bit material and any coatings must resist abrasion. As cutting lips dull over time, drilling performance decreases and holes become rougher.
The Flutes
Flutes are the deep, twisting grooves that start at the tip and spiral up the length of the drill bit. They serve to carry away debris created by the cutting lips so that the hole remains clear for continuous cutting. Wide, deep flutes provide greater chip clearance so drill bits can drill faster and deeper before clogging up. The spiral of the flutes also creates an upward force to rapidly extract chips. Without effective flutes, chips could reclog the cutting lips and overheat the drill bit. Proper flute design and size prevent this while keeping the hole open for smooth cutting.
The Margin
The margin is the narrow cylindrical land that surrounds the cutting lips. This area helps guide and support the cutting lips during the drilling process. It also regulates the flow of metal chips upward through the flutes. The margin continues the spiral of the flutes up along the drill bit's shank. An even and consistent margin enables stable cutting action and straight, round holes. If the margin becomes worn or uneven, it can lead to wobble and inaccurate hole shapes.
The Shank
The shank forms the rear portion of the drill bit that gets inserted into the chuck of the drilling machine. The shank must have a shape that properly matches the chuck for secure holding and centered spinning. Common shank types are cylindrical or hex-shaped. Keyed chuck grip and drive bits with a matching cylindrical shank profile. Keyless chucks tighten down on hex-shaped shanks through three or more jaws. The shank also sets the overall length of the drill bit for reaching specific depths. Longer shanks allow you to drill deeper holes without frequent bit changes. Heavy-duty shanks are needed for larger-diameter bits used in rigorous drilling operations.
Application of Drill Bits
Here are some of the key applications for different types of drill bits:
- Twist/Brad Point Bits - Used for drilling precise, clean holes in wood. The brad point tip prevents wandering and the spiral flutes clear out sawdust. Great for pilot holes.
- Masonry Bits - Carbide tipped with a hammer function to drill into concrete, bricks, mortar, and other masonry materials. The carbide and hammering break up tough materials.
- Tile/Glass Bits - Also carbide tipped but with a smooth action rather than hammering. Designed for clean holes in ceramic tile drill bit and glass. Use water to keep friction down.
- Forstner Bits - Cut large, flat-bottomed holes for tasks like mortises, inlays, and recessing cabinet hardware. Keep the workpiece stationary for a clean cut.
- Auger Bits - Used for quickly drilling large diameter holes into thick wood. The deep spiral flutes remove material efficiently from deep holes.
- Hole Saws - Outer-toothed rims bore wide holes for electrical boxes, plumbing, lights, vents, and more. Designed for speed and reach.
- Spade Bits - Inexpensive wood boring bits for rough holes. The flat spear point and spurs cut fast and aggressively.
- Step Bits - Can incrementally enlarge holes to specific sizes in sheet metal drill bits. Handy for conduit, plumbing, door hardware, and electronics.
- Counterboring Bits - Cut precise flat-bottom counterbore holes to allow countersunk fastener heads to sit flush with the material surface.
The right drill bit makes quick work of hole drilling and prevents damage, splitting, or walking for the material at hand. Using an improper bit can cause frustration, sloppy results, and damaged workpieces or bits. Understanding the drilling application leads you to the correct specialized bit for the job.
Popular Types of Drill Bits
Drill bits come in a wide array of styles, each engineered for specific materials and applications. Here is more detail on several of the most widely used:
Twist Drill Bits
Twist bits are the general-purpose workhorses of drilling. The cutting edges spiral up the conical drill tip, allowing it to efficiently carve out a circular path in the workpiece. The helical flutes then lift chips away from the cutting edges. Made of high-speed steel, twist drills bore smoothly through wood, plastic, mild steel, aluminum, and other soft materials. They can be found in fractional sizes from 1/16” up to 1⁄2” for home use.
Brad Point Bits
Brad-point bits possess the same spiral cutting edges and flutes as a twist bit but with a specialized tip. The pronounced brad point centers the bit precisely on the work surface without wandering to start cleaner hole edges. Side spurs further slice the wood grain for a smoother entry. This prevents tear-out on wood holes. The brad point’s flat tip also reduces drilling pressure compared to a standard twist bit point.
Masonry Bits
Masonry bits power through tough concrete drill bits, brick, mortar, and stone. The carbide cutting tips withstand abrasive wear while hammering action breaks up rigid materials. Water applied during drilling keeps dust down and reduces friction. Masonry bits come in sizes from 3/16” to 3⁄4” for drilling anchor holes or running conduit/cabling through concrete structures.
Spade Bits
If fast rough holes in wood are needed, spade bits are a good economical option. Their flat spear point aggressively rips into the wood. Peripheral spurs carve the hole edge while the screw tip clears loose chips. Large 1⁄4” to 1 1⁄2” sizes bore quickly with high torque drills. Applications include quickly boring holes for electrical boxes, plumbing, and rough carpentry.
Forstner Bits
Forstner bits consist of a central drill point surrounded by a flat, radial saw-like cutting rim. As the rim cuts, it leaves a flat-bottomed hole with minimal tearing on the exit hole edge. The large diameter hollow core drill bit evacuates chips efficiently. Forstners excel at mortising applications like door hinges, routing electrical channels, recessing cabinet hardware, or other shallow precision holes in wood.
Step Bits
Step bits provide a series of graduated cutting edges for enlarging holes to specific diameters in sheet iron drill bit or thin plastic. Stair-like edges bore incremental-sized holes in conduit, circuit boxes, ducting, drains, and more simply by twisting the step a bit deeper. Quick and accurate hole sizing eliminates multiple-bit changes. Durable carbide or cobalt steps resist wear when sizing tough materials like stainless steel.
Some Questions About Using Drills That You Should Know
How the Size of Drill Bits is Measured
Drill bit sizes are denoted by the diameter of the hole that the bit drills. There are two main measurement conventions:
- Fractional inches - Common fractional sizes are 1/16", 1/8", 1/4", etc. Measured in fractions of an inch.
- Metric - Diameters are denoted in millimeters. Common sizes are 1mm, 2mm, 5mm, and 10mm.
- Larger bits may be measured in inches instead of fractions. For example, a 1/2" bit or 12.7mm bit.
So a 1/4" drill bit drills a hole with a 1/4" diameter. Metric bits directly correlate to the diameter in mm. This standard sizing makes selecting the right bit for your desired hole simple.
How to Change Drill Bits
Changing bits in a drill is fast and straightforward:
- Unplug the drill to ensure it can't turn on accidentally.
- Open the chuck jaws fully using the chuck key or by hand if keyless.
- Remove the existing bit from the chuck.
- Insert the new bit into the chuck until it is fully seated.
- Tighten the chuck firmly using the key or your hands for a keyless chuck.
- Check that the bit is held completely centered and straight.
- Once fully secured, you can plug in and operate the drill again.
It's important to ensure bits are properly centered and clamped tightly to avoid wobble, bending, or dangerous slips while drilling. Follow manufacturer instructions for your specific drill and chuck style. With practice, bit changes become very quick and easy.
Where Should I Buy Reputable and Quality Drill Bits?
Finding high-quality drill bits at reasonable drill bit prices can be tricky with so many options available. However, Tonix Tools stands out as a great source for reputable, affordable drill bits for both professionals and DIYers.
Based in Boulder, Colorado, Tonix Tools offers an extensive selection of hand tool sets that combine durability, precision, and value. Their drill bit offerings range from basic adjustable joint drill bits to specialized crimping, cutting, gripping, and electronics versions.
What makes Tonix Tools drill bits appealing compared to cheaper brands is their use of drop-forged, heat-treated steel. This creates a sturdy drill bit body that resists bending and buckling when grip force is applied. Precision machining ensures smooth jaw action with minimal play. Gripping drill bits have specially textured jaws that firmly grip hoses, fittings, and other items without damage during turning or assembly.
While prices are certainly budget-friendly, Tonix Tools doesn't cut corners on performance. Their drill bits display quality touches like induction hardened teeth for wire cutters, comfortable molded handles, and handy quick-release locks. This merges affordability with functionality that rivals higher-priced brands.
DIYers, electricians, mechanics, and plumbers who want reliable, durable drill bits for a multitude of needs should check out the options at Tonix Tools. Their web address is www.tonixtools.com and their U.S. headquarters can be found at:
- 1942 Broadway Suite 314C, Boulder, CO 80302
- Email support: support@tonixtools.com
- Hotline: +1 (866) 698-8869
Take advantage of their expertise in manufacturing quality drill bits perfect for home projects or professional jobs without breaking the bank.
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