Choose an HSS Drill Bit Set by Sizes, Material and Chuck Fit

For occasional holes in wood, plastic and ordinary steel, start with a general-purpose high speed steel (HSS) drill bit set in the size system your projects use. Choose a compact set if its listed diameters cover your work; choose a fuller fractional or metric set when you regularly need intermediate sizes. For repeated stainless-steel drilling, consider a set specifically rated for stainless rather than buying more standard HSS bits.

The useful comparison is not “14 pieces versus 29 pieces.” It is which hole sizes, materials and drilling depths each set actually covers.

Four set formats worth comparing

These are specification-based options, not hands-on test rankings. Product details below reflect published listings checked on October 28, 2026. The fractional examples use US listings; the metric examples use Bosch’s UK listings. Match the part number and contents when shopping locally.

Your work	Example set	What it covers—and what to check
Occasional fractional-size DIY holes	DEWALT DWA1184, 14-piece HSS set	Selected sizes from 1/16 to 1/2 inch, including two 1/8-inch bits. That means 13 distinct diameters, not a continuous size sequence. DEWALT lists wood, plastic and metal applications and a 135° split point.
A full fractional sequence	Drill America DWD29J-SET, 29-piece set	Tillman Tools lists 1/16–1/2 inch in 1/64-inch increments, black-oxide HSS, round shanks and conventional 118° points. It covers fractional sizes, not numbered or letter sizes.
General metric work	Bosch PRO Metal HSS-G ProBox, 2608587013	Nineteen diameters from 1–10 mm in 0.5 mm increments, with 135° points. Shank diameter equals cutting diameter. The 25-piece 2608587017 extends the sequence to 13 mm.
Repeated metric stainless-steel holes	Bosch PRO Stainless Steel HSS-Co, 2608587014	Nineteen diameters from 1–10 mm in 0.5 mm increments. Bosch specifies cobalt-alloyed HSS for stainless steel; shank diameter equals cutting diameter.

Read the contents list, not just the range

A set marked “1/16–1/2 inch” may contain only selected sizes between those endpoints. For example, the DWA1184 contents list includes 5/32 and 3/16 inch but no 11/64 inch. Its spare 1/8-inch bit adds replacement capacity, not another hole diameter.

Before ordering, write down the diameters needed for your next few jobs and compare them against the actual contents:

• Fractional holes: look for the stated increment if you need a continuous sequence.
• Metric holes: a 0.5 mm sequence does not include sizes such as 4.2 mm. Add the exact bit separately when the job specifies it.
• Tapped holes: check the tap manufacturer’s chart. A fractional set alone does not supply numbered or letter drills. Our tap-drill guide for 1/4-20 threads explains one common example.

Duplicates can be useful if you repeatedly use a particular pilot size. For one upcoming project, however, a few correctly specified individual bits may serve you better than a large index.

Choose the cutting material before the finish

General HSS is a sensible starting point for mixed work: Bosch rates its PRO Metal HSS-G range for alloyed and unalloyed steel, non-ferrous metals, cast iron, plastics and wood. Its stainless range instead uses HSS with added cobalt. Those are application ratings, not proof that either set will outlast the other in your setup.

Do not treat “titanium” as a substitute for a material rating. HSS-TiN means HSS with a titanium-nitride coating. Coated sets can also have restrictions: Bosch’s HSS-TiN set listing explicitly excludes aluminium and requires a cooling agent. That restriction belongs to that product, not every coated bit.

If stainless work only requires one or two diameters, consider adding those sizes in cobalt-alloyed HSS rather than replacing your whole set. See cobalt versus titanium drill bits for the alloy-versus-coating distinction.

Check chuck fit and usable depth

A large cutting diameter does not tell you whether the shank fits your drill. Bosch’s 25-piece HSS-G set reaches 13 mm and uses equal-diameter shanks: its largest bit therefore exceeds a 3/8-inch chuck’s nominal 9.525 mm capacity. Check the drill’s manual and the bit’s shank specification rather than assuming every set fits every drill.

Also compare working length, not just overall length. In the same Bosch listing, the 19-piece HSS-G set’s 1 mm bit has a working length of 12 mm despite being 34 mm long overall. The portion held in the chuck is not extra drilling reach.

Once the set arrives, secure the work, wear eye protection, keep bits sharp and follow the bit manufacturer’s material-specific cooling or lubrication instructions. “High speed steel” is not a command to run the drill at maximum speed: CCOHS drill guidance advises reducing speed where possible for hard material and easing the feed before breakthrough. Small stock should be clamped—not held in your other hand.