Best Twist Drill Bits AI pick
Chosen by an AI model from its trained knowledge, with its reasoning.
AI pick: DeWalt Pilot Point Titanium DW1361
A complete jobber-length set with split points that start without walking, suited to the wood, plastic and mild-steel drilling most households and tradespeople do.
Not for: Anyone drilling mostly stainless or hardened steel, who should buy cobalt bits instead.
AI picks by need
For stainless and hard metals
Irwin Cobalt M-35 (line)
Cobalt is alloyed through the whole bit, so it holds an edge in stainless and keeps working after resharpening.
Not for: Wood-only users, who would pay for heat resistance they never use.
For machine shop, individual replacement bits
Precision Twist Drill (brand)
Industrial-grade bits sold individually and in dozens, so you can replace the sizes you wear out.
Not for: Casual DIYers who only want one boxed set.
What the AI looks for in Twist Drill Bits
- Steel grade
- HSS for wood and mild steel; cobalt (M35, about 5% cobalt, or M42, about 8%) for stainless and hard alloys Cobalt is part of the alloy and resists heat, which dulls plain HSS quickly in tough metals.
- Point angle
- 135° split point for metal and general use; 118° for softer materials A split point self-centers without a center punch, and the flatter 135° angle reduces walking on hard surfaces.
- Coating vs alloy
- Treat titanium (TiN) and black oxide as surface treatments, not as a substitute for cobalt Surface coatings wear off at the cutting edge and are removed by resharpening.
- Size range and increments
- A full fractional index runs 1/16 to 1/2 inch in 1/64 steps (29 bits) Smaller sets skip the in-between sizes you need for tap drills and clearance holes.
- Length class
- Stub or mechanic's length for rigidity and accuracy, jobber for general use, long or extra long only for reach Longer flutes flex and wander more, and they break more easily in metal.
- Shank
- Reduced or 3-flat shanks on bits larger than 3/8 inch if your chuck is 3/8 inch Flats stop the bit spinning in the chuck under high torque.
Brands that matter
- DeWalt: Pilot Point split-point sets are a reliable general-purpose choice.
- Irwin: A wide retail range, including cobalt sets for metal.
- Milwaukee: Red Helix titanium and cobalt bits for tradespeople.
- Drill Hog: A US cobalt specialist marketed toward metalworkers.
- Norseman: US-made industrial bits; strong in cobalt and specialty lengths.
- Chicago-Latrobe: Industrial bits, including stub and mechanic's lengths.
- Precision Twist Drill: Shop-grade bits sold individually and in bulk.
What to avoid
- Large unbranded sets with many bits, which often use soft steel that dulls on its first metal hole
- Treating gold titanium coating as if it were cobalt for stainless steel
- Running bits fast and dry in steel; use lower speed and cutting fluid
- Sets without a labeled index case, which makes it hard to find and replace sizes
Questions
Titanium or cobalt?
Titanium is a surface coating on HSS and is fine for general use. Cobalt is alloyed through the bit, so it is the choice for stainless and hard steel and still works after sharpening.
Do I need a center punch?
With 135° split-point bits you usually don't on flat stock. With 118° non-split points you should punch first to stop the bit walking.
Extra Long Drill Bits
Choose the same steel as for the parent pick (HSS for general use, cobalt for hard metals) and buy extra-long bits only for the reach you need. Feed them slowly, because long flutes flex and wander.
Jobber Drill Bits
Jobber length is the standard twist-drill length, so the parent's pick (DeWalt DW1361) and its cobalt alternative apply directly.
Long Length Drill Bits
Use the parent's steel choice in a longer flute only when you need the depth or reach. Long bits deflect more, so start the hole with a jobber or stub bit.
Mechanic's Length Drill Bits
Mechanic's length bits are shorter and stiffer than jobbers, so they wander and break less in metal. Pick cobalt as for the parent, from industrial brands such as Chicago-Latrobe or Norseman.
Short Length Drill Bits
Short (stub) bits follow the parent's steel and point-angle rules and are the most rigid choice for accurate holes in metal and tight spaces.