Best Flat Shank Drill Bits for Wood, Metal, and DIY Projects
The best flat shank drill bits depend on the material and the chuck you use. For general-purpose drilling, the DEWALT 14-piece set has three-flat shanks and covers plastic, wood, and metal. The BOSCH cobalt set is better suited to demanding metalwork, while the COMOWARE set offers a hex shank for quick-change tools. The options below compare shank style, material, bit range, and intended use so you can choose a set or single bit that fits your task.
| Product | Best For | Shank or Size Detail |
|---|---|---|
| DEWALT DWA1184 | General-purpose drilling | Three-flat shank; 14 pieces |
| COMOWARE Titanium Set | Quick-change DIY use | 1/4-inch hex shank; 16 pieces |
| BOSCH CO14B | Metal drilling | Three-flat shank; 14 pieces |
| 11/16-Inch M35 Cobalt Bit | Large-diameter metal holes | Reduced three-flat shank |
| 13-Piece M35 Cobalt Set | Mixed-material drilling | 1/16–1/4-inch range |
DEWALT DWA1184 14-Piece Drill Bit Set
Best for: Homeowners and DIY users who want a versatile set for plastic, wood, and metal. Its three-flat shank matches the flat-shank focus of this guide, and the 14-piece assortment provides multiple bit sizes for general tasks.
The bits use high-speed steel and have a 135-degree split-point tip designed to help reduce walking when starting a hole. DEWALT also lists a tapered web design intended to improve durability and resist breakage. Those features make this a strong general-purpose choice rather than a specialized cobalt set for tough metal applications.
Limitation: The product information does not specify the individual bit sizes, so confirm the set’s size range before buying for a particular hole diameter.
COMOWARE Titanium-Coated Hex Shank Set
Best for: DIY users who need bits for wood, plastic, or aluminum alloy and use a compatible quick-change chuck. This 16-piece set spans 1/16 to 1/4 inch and has a 1/4-inch hex shank. That is a hex profile, not the same shank shape as a traditional three-flat drill bit.
COMOWARE lists high-speed steel construction with a titanium coating and two flutes designed to clear chips and debris. The product description also says its hardened, honed cutting edge and staggered cutting teeth are intended to support clean, precise holes. The hex shank is described as fitting power tools more easily and locking into quick-change chucks.
Limitation: Choose another option if you specifically need a three-flat shank; this set uses a 1/4-inch hex shank instead.
BOSCH CO14B Cobalt Drill Bit Set
Best for: Users drilling metal who want a cobalt set with three-flat shanks. The 14-piece set uses M42 alloy with 8% cobalt, and its jobber-length bits are described for stainless steel, cast iron, titanium, light-gauge metal, and aluminum.
BOSCH lists heat resistance and a surface-hardened tip for penetrating tough, abrasive materials. The three-flat shank is a useful distinguishing detail for buyers comparing flat-shank options, while the included case keeps the set together. This is a more specialized metalworking choice than the DEWALT general-purpose HSS set.
Limitation: Its listed applications focus on metal, so it may be more specialized than needed for buyers who mainly drill wood or plastic.
11/16-Inch M35 Cobalt Drill Bit
Best for: Buyers who need one larger 11/16-inch bit rather than a multi-size set. The listed specifications identify M35 cobalt, a TiAlN coating, a 135-degree split point, and a reduced 1/2-inch three-flat shank. Its stated intended materials include hardened stainless steel and thick cast iron.
The six-inch overall length and reduced shank are important fit details to check against your drill and workpiece. This option is better for a specific large hole than for general home drilling, because it is a single bit rather than an assortment.
Limitation: The supplied product information does not include further feature details or a set of alternate sizes.
13-Piece M35 Cobalt Drill Bit Set
Best for: Buyers seeking a compact cobalt assortment for several materials. The 13-piece set covers 1/16 to 1/4 inch and lists M35 high-speed steel, 135-degree split points, jobber length, and a metal storage case. Its stated uses include cast iron, stainless steel, aluminum, wood, and plastic.
This set offers more size variety than the single 11/16-inch cobalt bit and a broader listed material range than the BOSCH set. Consider it if you need smaller common sizes in one case, particularly for mixed workshop tasks.
Limitation: The listed range ends at 1/4 inch, so it will not cover larger holes without a separate bit.
Buying Guide: How to Choose Flat Shank Drill Bits
What does “flat shank” mean?
A flat or three-flat shank has flattened sides intended to help secure the bit in a chuck. Check the product’s exact shank description: a three-flat shank and a hex shank have different shapes. The COMOWARE set has a 1/4-inch hex shank, while the DEWALT and BOSCH sets specify three-flat shanks.
Which bit material suits the job?
High-speed steel is a general-purpose choice for materials such as wood, plastic, and lighter metal tasks. Cobalt options are specifically listed for tougher metals, including stainless steel and cast iron. Match the bit to the work material, and do not assume that a coating alone makes a bit suitable for every metal.
Should you buy a set or a single bit?
Choose a set when you need several hole sizes or want a case for storage. A single large bit is more appropriate when the required diameter is known in advance. Compare the stated size range with your project before choosing; a set’s piece count does not by itself show which sizes are included.
Frequently Asked Questions
Are three-flat and hex shank drill bits the same?
No. Both have non-round features, but their profiles differ. Check the shank type and your chuck before buying.
Which option is best for stainless steel?
The BOSCH CO14B and the M35 cobalt options list stainless steel among their intended applications. The 11/16-inch bit is for a specific larger hole; the sets provide multiple smaller sizes.
Do split-point tips help keep a bit from walking?
A split-point tip is designed to help reduce walking as the bit starts. The DEWALT set specifically lists a 135-degree split point for this purpose.
What should I check before buying?
Confirm shank profile, bit diameter, material suitability, and whether you need one bit or an assortment. Also check the exact size range when it is not listed in the product details.