Match the bit to the material, required diameter and drill chuck. Cobalt-containing HSS bits are an option for some stainless-steel applications, but the exact manufacturer’s material guidance is what matters.
Establish what you are drilling
‘Metal’ is too broad to be a complete buying specification. Identify the material as closely as possible, then check the bit manufacturer’s application list. Bosch, for example, identifies its PRO Stainless Steel HSS-Co range as designed for stainless steel, with cobalt added to the high-speed steel. That does not mean every bit carrying the word ‘cobalt’ is equivalent, or that it suits every drilling setup.
Buy the dimensions you need
List the hole diameters and any length or access constraints before choosing a set. Check both the working length and overall length where they matter. Look at the shank size and format and confirm compatibility with your chuck. A listing that puts several sizes under one photograph needs careful attention: the selected option may be a single bit rather than the entire set shown.
Compare a set with individual replacements
A small set can make sense for varied hobby work. If your projects repeatedly use one diameter, a pack of that exact size may be more practical than another large assortment. Count useful sizes rather than headline pieces; duplicate screwdriver accessories in a combination kit do not add to your metal-drilling coverage. Keep a written inventory of the sizes you have before adding another box.
Do not use material claims as operating instructions
Bit selection is only part of drilling safely and successfully. Follow the tool and accessory instructions for setup, workholding, speed and any cutting fluid. This article does not provide operating settings, and there is no single speed recommendation suitable for every diameter, material and machine. If the manufacturer’s application information is missing, choose a source that supplies it rather than relying on a marketplace title.
Record which product worked for your own application
Keep the manufacturer and product reference with the size. That makes a replacement order more useful than a search for ‘the gold-coloured ones’. Surface appearance is not a reliable substitute for a specification. On delivery, confirm the sizes and quantities before putting the bits into an unlabelled mixed tray. A modest, well-identified collection is easier to replenish than a drawer of tools whose origin and intended use have been lost.
Quick comparison
| Decision | What to check |
|---|---|
| Material suitability | Exact manufacturer’s application list |
| Size coverage | Required diameters and useful lengths |
| Drill compatibility | Shank format and chuck capacity |
| Pack value | Useful bits, not total accessory count |
Your pre-purchase check
- Material identified
- Diameter and length confirmed
- Chuck compatibility checked
- Set compared with individual sizes
READY TO EXPLORE OPTIONS?
Check the exact product with the retailer.
Use the search as a starting point. Confirm the variant, seller, specification, price and delivery before buying.
Ad — Amazon affiliate link. We earn commission from qualifying purchases.
Search Amazon UKAd — Amazon affiliate links. We earn commission from qualifying purchases. How our links work.
Sources & scope
Sources checked 25 October 2026. Technical points are linked above; the comparison framework and purchase checklist are our editorial guidance. This is a desk-researched article, not a hands-on product test. Follow current manufacturer instructions and seek competent advice for unfamiliar or safety-critical work.
How we prepare our guides ↗
