Choose the Right Small Brad Point Bit for Your Hole

A 5/64-inch brad point drill bit has a nominal cutting diameter of 0.078125 inch, exactly 1.984375 mm. Choose it for a wood hole that calls for that diameter when you want a locating point and scoring edges for a clean, accurately placed entrance. It is not an exact substitute for a 2 mm bit, and its small shank must be within your drill chuck’s gripping range.

Select your required size, material and chuck fit to check whether this bit suits the job.

You do not need to buy a full set to obtain this size. McFeely’s lists an individual Fuller HSS brad-point bit with a 5/64-inch cutting diameter and round shank, 1-inch flute length and 2-inch overall length. Those specifications describe that particular bit, not every product sold under the same size label.

The buying decision comes down to three separate checks: whether the hole diameter is correct, whether the chuck can grip the shank, and whether the bit’s cutting length and application suit the work. A listing that gets the diameter right can still leave the other questions unanswered.

The Exact Size Is Slightly Smaller Than 2 Mm

“5/64th,” “5/64” and “5/64-inch” refer to the same fractional-inch size in this context. The fraction describes the nominal cutting diameter, not the bit’s length or the depth of hole it can drill.

Size Detail	Value
Nominal diameter	5/64 inch
Decimal inches	0.078125 inch
Exact metric conversion	1.984375 mm
Difference from 2 mm	0.015625 mm smaller

The conversion is exact, but the diameter of a finished hole is not guaranteed to match that conversion exactly. Bit condition, drill alignment and the way the work is held can affect the result. For a fitted pin or another part that must seat consistently, test the actual bit and setup rather than relying only on the size printed on the package.

A 2 Mm Bit Is Close, Not Identical

A 2 mm bit is 0.015625 mm larger than a 5/64-inch bit, calculated from their nominal diameters. That makes it a close alternative where the job allows a slightly larger hole, not a direct replacement wherever a drawing or fastener instruction specifies 5/64 inch.

If a part calls for 2 mm, buying a 5/64-inch bit because it is described as “about 2 mm” reverses that substitution: you are choosing the smaller nominal diameter. Whether that works depends on the fit the part needs. The supplied sources do not establish an acceptable tolerance for your pin, screw or assembly.

For an appearance-only hole with no mating component, the difference may not govern the choice. For a specified pilot or fitted hole, keep the requested size unless the part maker permits a substitute. A scrap test can show how your setup performs, but it does not change the specification you are trying to meet.

Brad-Point Geometry Matters More Than the “Wood Bit” Label

A brad-point bit has a projecting center point that helps locate the hole on your mark. Its outer scoring edges cut the perimeter before the main cutting edges remove the wood inside it. Lee Valley’s description of its HSS lipped brad-point drills explains how the scoring lips produce a clean entrance and smooth sidewalls.

That geometry is the reason to choose a brad point for a small woodworking hole. It helps with starting position and the appearance of the cut at the surface. It does not make a 5/64-inch hole a different nominal size from one made with a conventional 5/64-inch twist drill.

A twist bit remains an option when the entrance appearance is less important. If you are buying specifically for clean-entry woodworking, however, check that the product description actually says brad point. “Wood drill bit” alone does not identify the tip geometry. A photograph should support the description, but an unclear photograph is not a substitute for a stated point type.

Our brad-point selection and use guide covers the broader choice between bit styles. For this purchase, keep the distinction narrow: the diameter determines the nominal hole size; the point and cutting edges determine how the bit starts and cuts.

“HSS” identifies the steel, not the tip or a universal material rating. The Fuller listing combines HSS construction with a brad-point tip. For plastic or metal, confirm the particular product’s application rating rather than carrying a woodworking recommendation over to another material.

Check the Chuck’s Minimum Grip, Not Just Its Maximum

The cited Fuller bit has a 5/64-inch round shank. Lee Valley also specifies that its 5/64-inch bit is shanked to size. For these examples, the chuck must therefore grip a shank as small as the cutting diameter.

A chuck’s maximum capacity does not answer whether it can hold this bit. Look for the gripping range in the drill or chuck documentation, paying attention to the minimum. If that information is missing, the draft sources do not supply a compatibility answer for your drill.

This check matters before ordering, particularly when the bit is intended for a drill you normally use with larger accessories. Do not assume that a chuck which accepts large bits necessarily closes far enough to grip this one securely. Conversely, do not reject the bit simply because the drill is large; the documented chuck range is the relevant specification.

With the drill stopped, check that the jaws hold the straight shank securely and that the bit is seated straight. Do not tighten onto the cutting flutes to compensate for a poor fit. If the chuck cannot grip the shank properly, use a compatible holding setup rather than trying to make the small bit stay put through extra drilling pressure.

Also separate shank diameter from cutting diameter when comparing other listings. The two cited products are shanked to size, but that does not establish the shank specification of every 5/64-inch bit. If a seller lists only the cutting diameter, the chuck-fit question is still open.

One Inch of Fluting Is Not a Guaranteed One-Inch Depth

Both cited individual-bit examples have 1 inch of fluting and a 2-inch overall length. These are different measurements with different uses.

Specification	Cited Examples	What It Tells You
Cutting diameter	5/64 inch	Nominal hole size
Round shank	5/64 inch	Chuck-fit requirement
Flute length	1 inch	Fluted cutting section
Overall length	2 inches	Full bit length

Overall length includes the shank. It is not usable drilling depth, and part of that length must remain held in the chuck. Buying a 2-inch-long bit does not mean it can make a 2-inch-deep hole.

Flute length is more relevant to drilling depth because the flutes provide space for chips to leave the cut. Even so, the entire fluted length should not be treated as an automatic depth rating. Leave room for chip evacuation, and withdraw the bit periodically when chips are accumulating in a deeper hole.

If the planned hole approaches the available flute length, check the particular bit’s suitability before buying. The supplied listings give dimensions but do not establish a universal safe maximum drilling depth. A longer overall length without additional useful fluting would not, by itself, resolve that question.

For a blind hole, the projecting center point adds another consideration. The deepest point reached by the tip is not the same as the end of the full-diameter portion of the hole. In thin stock, setting depth without accounting for that projection can let the point break through while the main cutting edges remain inside the wood.

Use the Screw Maker’s Pilot Size

5/64 inch is a hole size, not a universal pilot size for small screws. Choose a screw pilot diameter from the screw maker’s guidance for the wood you are using, then choose a bit that matches it.

The brad point can help place that pilot accurately, but its geometry does not determine which pilot diameter the screw needs. A bit being marketed for woodworking is not evidence that it is suitable for every small screw, hinge or piece of hardware.

If the instructions specify 5/64 inch, this size is the relevant starting point. If they specify 2 mm, recognize that the fractional-inch option is smaller. If they provide no pilot figure, the supplied sources do not fill that gap; obtain guidance for the actual fastener rather than selecting a diameter from the screw’s general appearance.

Depth needs its own check. A correctly sized pilot can still be wrong for the installation if it is too shallow or if the point reaches through the opposite face. Test the selected diameter and depth in matching scrap before committing to the finished part, especially where the back face must remain unmarked.

Keep the Small Bit Aligned and Clear of Packed Chips

Wear eye protection and clamp the workpiece. Seat the center point on the mark before starting the cut, keep the drill aligned with the intended hole, and use ordinary rotary drilling—not hammer mode.

The center point helps establish the starting position; it does not prevent the drill from tilting once cutting begins. Apply controlled feed without levering the drill sideways. If the angle is wrong, stop and reset the setup rather than trying to steer the bit by bending it while it is engaged.

Clear chips periodically in deeper holes. Forcing the drill while the flutes are packed does not solve the chip-clearance problem. Withdraw along the hole’s axis and keep the work clamped so that clearing the bit does not change the hole’s alignment.

The cited sources do not provide a speed or feed figure for this particular bit and setup. Use any instructions supplied with the bit and drill instead of treating a general woodworking speed as a model-specific recommendation.

Back Up a Through-Hole’s Exit Face

A clean brad-point entrance does not guarantee a clean exit. Unsupported fibers on the back face can still tear out as the bit passes through.

Clamp scrap wood tightly against the exit face so the bit continues into supported material. WOOD magazine recommends a scrap-wood backer regardless of bit choice. The backer addresses the exit condition; it is not a replacement for accurate alignment or a securely clamped workpiece.

Check that the planned exit lands over the backer rather than beyond its edge. If the hole’s appearance matters on both faces, test the arrangement in scrap with the same support before drilling the finished piece.

Test Blind-Hole Depth With the Actual Bit

For a blind hole, establish whether the required depth refers to the full-diameter hole or the deepest reach of the center point. That distinction matters when a part must seat to a particular depth or when little material remains beneath the hole.

Set the depth using the actual bit, then test the complete setup on matching scrap. Inspect both the hole and the opposite face. A depth setting that appears correct from above can still leave a point mark or breakthrough underneath.

Buy the Individual Bit Unless You Need the Other Sizes

If 5/64 inch is the only missing size in your kit, the individually listed Fuller bit is the focused purchase. It lets you obtain the required diameter without buying unrelated sizes.

Fuller also lists a 28-piece HSS brad-point set spanning 5/64 to 1/2 inch. That establishes that the set includes the small size at the bottom of its stated range; it does not establish that a set is better value for your job. The draft provides no prices for a cost comparison.

Before ordering either option, confirm the exact diameter, brad-point description, shank size and lengths on the current listing. For the cited individual examples, the key specifications are a 5/64-inch cutting diameter, a same-size round shank, 1-inch flutes and 2-inch overall length. Buy on those details and your hole requirements, not on the “wood bit” label alone.