Chart · Drilling and fasteners

Wood Drill Bit Types: A Chart of Nine Bits and Their Holes

The sheet above draws the cutting end of nine bits made for wood and sets out, in each maker's words, the hole it makes, how it starts and which tool it is meant for. Below, the four ways those bits start a hole, and what this chart leaves to other pages: sizes, square holes, and bits for metal or masonry.

About this guide

Written by: BenchRoot Editorial
Published: 15 October 2026
Reading time: 2 min
Level: Beginner

Bits for wood

Nine Bits, Nine Holes.

Answers: Which bit makes which hole in wood?
Units: bit type · maker's stated use

Each kind of bit is shaped for one kind of hole. The sheet below draws their cutting ends and sets out what each is for, in its maker's words — including where a maker limits the tool it may be used in. For a bit's diameter in another size system, use the drill bit size chart.

Twist
Brad point
Spade
Auger
Forstner
Hole saw
Self-feed
Countersink on taper drill
Plug cutter

Wood-boring bits at a glanceWhat each bit is for and how it starts, as the named maker describes its own bits; another maker's bit of the same type may differ.
Bit	Hole it makes	How it starts and cuts	Tools, per the maker	Source
Twist	Round through or blind hole; the general-purpose bit	A point ground for metal as well as wood (WEN calls them metal-piercing)	WEN: metal-piercing twist bits may be used on wood, brad point preferred	WEN 4214 manual
Brad point	Clean round hole in wood	A centering tip for exact positioning; wide flutes clear chips	Bosch: portable drills and drill presses	Bosch brad point bits
Spade	Fast larger hole, 1/4–1-1/2 in in Bosch's range	Spur-and-reamer tips pre-cut the wood; Bosch's fully threaded tip pulls the bit in	Bosch: corded and cordless drills	Bosch Daredevil spade bits
Auger	Deep hole through framing; 6-1/2 in long in Bosch's line	A threaded tip (Bosch: decreased pitch) that feeds the bit	Bosch: rotary drills/drivers. WEN: not in its drill press — augers can lift and spin the work	Bosch Daredevil auger bits; WEN 4214 manual
Forstner	Flat-bottomed, pocket, angled and overlapping holes	A center spur locates; the outer rim guides the cut	Freud and Diablo: hand-held drills and drill presses	Freud and Diablo product data
Hole saw	Large hole cut by a toothed cup	A pilot bit in the arbor centers the saw	Milwaukee: its small arbor takes saws up to 1-3/16 in	Milwaukee arbor and pilot bit
Self-feed	Repetitive large holes, as for pipe and conduit	A center feed screw pilots the bit and pulls it through	Milwaukee: hex shank for a drill chuck	Milwaukee SELFEED bit
Countersink on taper drill	Pilot, shank clearance, countersink and counterbore for one screw size in one pass	The tapered drill leads; the countersink sets on it by two screws	Fuller: sized by screw gauge	W. L. Fuller catalog
Plug cutter	Cuts a wood plug to fill a counterbore	Cuts down around the plug; the plug stays in the board	Fuller: plugs matched to its counterbores	W. L. Fuller catalog

Silhouettes are not to scale. Square holes for mortises are cut by a bit turning inside a hollow chisel in a mortiser, not by any bit here. A bit's shank, not its cutting diameter, is what the chuck must hold.

How each bit starts a hole

Four ways a bit locates and starts
Start	Bits	What the maker says
A sharp centre point	Brad point	Bosch: a centering tip for exact positioning and accurate starts
A centre spur inside a rim	Forstner	Freud: the spur locates the centre and the rim guides the cut
A threaded tip or feed screw	Spade, auger, self-feed	Bosch and Milwaukee: the tip pulls the bit through the wood
A pilot or leading drill	Hole saw, countersink	Milwaukee: a pilot bit centres the saw; Fuller: the taper drill leads the countersink

Each start as its maker describes its own bits. WEN rules auger bits out of its drill press, saying they can lift the work off the table and whirl it around.

Which tool a bit belongs in is its maker's call, and the makers do not all say the same thing for the same type. Bosch lists its brad-point bits for drills and drill presses but its spade bits for drills only; Freud lists its Forstner bits for both. Read the maker's statement for the bit in your hand. How each fits a chuck, and which tool each maker allows, is set out in the guide to wood drill bits.

What this chart leaves to other pages

Sizes. A bit's diameter in fractional, number, letter and metric sizes is on the drill bit size chart; this sheet is about shape, not diameter.
Holes for screws. Pilot, clearance and counterbore sizes by screw gauge are on the pilot hole chart.
Square holes. A mortise is cut by a bit turning inside a hollow chisel in a mortiser, or chopped by hand; see the mortise and tenon guide.
Metal and masonry bits. Bits for those materials are not drawn here; WEN's manual allows metal-piercing twist bits in wood but prefers brad points.
Technique. Starting, feeding, backing and depth for every bit are in drilling clean holes.
Buying. Seven makers' bit lines, and what to compare between them, are in choosing drill bits.

Choosing a bit from the chart

Matching a bit to the job

4 checks

Hole shape first: through, stopped, flat-bottomed or a screw seat
Tool second: the bit's maker lists it for a drill, a drill press or both
Shank within the chuck's capacity
Size from the size chart

Sources

Each row is the named maker's description of its own bits; another maker's bit of the same type may differ in tip, shank and the tools it is rated for. The silhouettes are schematic. No bit was tested.

1.
Model 4214 12-inch Variable Speed Drill Press manual (2015), as hosted by a retailer. WEN Products, 2015.
Used for: Brad point bits preferred for wood, metal-piercing twist bits usable, and auger bits not to be used in its drill press.
2.
Brad Point Drill Bits. Bosch.
Used for: A centering tip for exact positioning, extra-wide flutes, a cylindrical shank, and use in portable drills and drill presses.
3.
Daredevil Standard Spade Bits. Bosch.
Used for: Spur-and-reamer tips that pre-cut the wood, a fully threaded tip that pulls the bit through, 1/4 to 1-1/2 in, for corded and cordless drills.
4.
Daredevil Auger Bits. Bosch.
Used for: Auger bits for rotary drills/drivers, 6-1/2 in long, with decreased-pitch tips.
5.
PB-100 Forstner Bit Set and carbide Forstner bits. Freud.
Used for: Flat-bottomed, pocket, angled and overlapping holes; a centre spur to locate and an outer rim to guide; hand-held drills and drill presses.
6.
FB-007 High-Speed Steel Forstner Bit. Diablo (Freud).
Used for: A spur that resists walking; a 3/8 in minimum chuck.
7.
HOLE DOZER Small Arbor with Cobalt Pilot Bit (49-56-7110). Milwaukee Tool.
Used for: A hole saw arbor whose pilot bit centres the saw; the small arbor takes saws up to 1-3/16 in.
8.
SELFEED Bit 2-1/8" (48-25-2122). Milwaukee Tool.
Used for: A centre feed screw that pilots the bit and pulls it through; an inside cutting plane that shaves the hole; repetitive large holes for pipe and conduit; a hex shank.
9.
Countersinks, Counterbores, Tapered Drills, Plug Cutters catalog (PDF dated 2006), page 4: Recommendations for Wood Screw Predrill Sizes and Lengths. W. L. Fuller, Inc., 2006.
Used for: Countersinks on taper point drills that predrill, clear the shank, countersink and counterbore in one operation, and plug cutters that leave the plug in the board.

About this chart

Written by BenchRoot Editorial. How BenchRoot sources, checks and corrects its pages is set out in the Editorial Policy. If something here is wrong or unclear, the contact page explains how to tell us.