Bosch Pro Cobalt Drill Bits
Drilling stainless brackets or steel plate? Bosch professional cobalt drill bits tackle metal where ordinary HSS bits struggle with heat.
For fitters and fabricators, cobalt-alloyed HSS offers better heat resistance, but speed and lubrication still matter. Choose individual replacements or a Bosch professional cobalt drill bit set to cover your fixing sizes.
What Are Bosch Professional Cobalt Drill Bits Used For?
- Drill fixing holes through stainless steel brackets using controlled speed, suitable cutting lubricant and firm feed pressure.
- Prepare bolt holes in steel angle and plate for workshop fabrication, keeping the work clamped so the bit cannot snatch it round.
- Open mounting holes in metal equipment supports during plant room installations, selecting the diameter specified for the fixing.
- Drill repeated holes in tougher alloy steels within the bit's stated material capability, where heat resistance matters more than it does in mild steel.
Choosing the Right Bosch Professional Cobalt Drill Bits
Buy for the metal and hole size first; cobalt does not make the wrong bit suitable.
1. Match the Bit to the Metal
If you regularly drill stainless or tougher steels, choose cobalt-alloyed HSS with those materials listed in its specification. For routine mild steel work, compare Bosch Pro HSS Drill Bits before paying for heat resistance you may not need.
2. Individual Bits or a Set
If you use the same clearance diameter all week, buy replacements in that size. Choose a Bosch professional cobalt drill bit set for varied installation work, but check the included diameters and increments rather than judging it by the number of pieces.
3. Check Shank and Working Length
Check that your chuck accepts the shank and that the fluted length suits the material thickness. Keep the bit as short as the job allows to reduce flex. With Bosch 18V Combi Drills, use rotary drilling mode, not hammer.
Who Uses Bosch Professional Cobalt Drill Bits?
Metal fabricators and mechanical fitters use Bosch professional cobalt metal drill bits for brackets, supports and steel assemblies. Maintenance teams keep common diameters ready for replacement fixings, while sparkies use them for drilling suitable metal mounting plates with hammer action switched off.
The Basics: Understanding Cobalt Drill Bits
Cobalt drill bits are high-speed steel bits alloyed with cobalt. The useful difference is how well the cutting edge retains hardness as drilling generates heat.
1. Cobalt Is in the Alloy
Cobalt is not simply a surface coating. M35 denotes HSS containing approximately five per cent cobalt. If you are looking for Bosch professional M35 cobalt bits, check the individual specification rather than assuming every cobalt bit uses that grade.
2. Heat Resistance Still Needs Correct Technique
Bosch professional HSS cobalt bits still need an appropriate cutting speed, suitable lubrication and positive feed. Letting a blunt bit rub on stainless can work-harden the surface, making the next attempt harder rather than easier.
Accessories for Controlled Metal Drilling
Hold the work properly and control heat before starting the hole.
1. Metal Cutting Lubricant
Use lubricant suited to the metal and drilling method to reduce friction and help protect the cutting edge. Apply it as directed rather than waiting until the bit overheats.
2. Clamps or a Drill Vice
Secure brackets and plate before drilling. A bit catching at breakthrough can spin a loose workpiece; holding it by hand is not a substitute for clamping.
3. Centre Punch
Mark a suitable starting point accurately on metal where the job permits. A punch mark helps locate the tip before the cutting edges engage.
Choose the Right Cobalt Drill Bits for the Job
Match the size, material rating and pack format to the work you actually do.
| Your Job | Bit Selection | Key Features |
|---|---|---|
| Repeated bracket fixing holes | Individual cobalt bit | Exact clearance diameter and suitable working length |
| Mixed maintenance drilling | Cobalt drill bit set | Useful diameter spread and clearly marked storage |
| Stainless steel fabrication | Cobalt bit rated for stainless | Confirmed material suitability and correct cutting speed |
| Drilling thicker steel sections | Correct-length cobalt bit | Sufficient flute length and provision for clearing swarf |
Common Buying and Usage Mistakes
- Running too fast overheats the cutting edges. Follow cutting-speed guidance for the material and diameter; larger bits generally need lower rotational speeds.
- Using too little feed on stainless lets the bit rub rather than cut. Maintain controlled pressure and stop if it stops producing chips.
- Buying by set size alone can leave you without the diameter the drawing specifies. Check every included size before ordering.
- Twisting the drill sideways to enlarge a hole can snap the bit. Use the correct diameter or an appropriate hole-finishing tool instead.
Cobalt Bits vs Standard HSS Bits vs Holesaws
Cobalt Drill Bits
Choose these for tougher metals where retaining edge hardness under heat matters. They cost more than basic HSS and still need careful handling; side loading can break them.
Standard HSS Drill Bits
These are a practical choice for everyday mild steel drilling. They are not always the economical option for repeated stainless work, where cutting edges can lose performance quickly.
Metal-Cutting Holesaws
For larger circular openings, compare Bosch Pro Holesaws & Accessories and check metal suitability and cutting depth. For sheet profiling rather than round holes, Bosch Metal Shears serve a different job.
Maintenance and Care
Clear Swarf Safely
Stop the tool before clearing chips with a suitable brush. Do not pull sharp swarf away with bare fingers or wear gloves near rotating machinery.
Store Clean and Dry
Remove residue after use and dry the bits before putting them back in their case. Keep sizes separated so cutting edges do not knock together in the tool bag.
Inspect the Cutting Edges
Stop using bits with chipped edges, cracks or bent shanks. Sound cobalt bits can be professionally resharpened, but the correct point geometry must be maintained.
Why Shop for Bosch Professional Cobalt Drill Bits at ITS?
ITS stocks the Bosch professional cobalt drill bit range, covering individual replacement sizes and sets for mixed metal drilling. Stock is held in our own warehouse, ready for next-day delivery on eligible orders. Check current availability for your required sizes, or browse Bosch Pro Drill Bits for other drilling materials.
Bosch Professional Cobalt Drill Bits FAQs
What are cobalt drill bits used for?
They drill metal, particularly stainless steel and tougher steels within the bit's stated rating. Their cobalt-alloyed HSS construction improves heat resistance. They are not masonry bits and must not be used with hammer action.
Are cobalt drill bits better than HSS?
Cobalt bits are themselves a type of HSS. Compared with standard HSS, they generally retain cutting-edge hardness better at elevated temperatures. That helps with demanding metal drilling, but standard HSS can be sufficient for occasional mild steel holes.
Can cobalt drill bits cut stainless steel?
Yes, provided the selected bit is rated for the stainless grade and the drilling conditions are suitable. Clamp the work, use appropriate lubricant and follow the recommended speed. Stop if the bit rubs without cutting, as stainless can work-harden.
Are Bosch cobalt drill bits any good?
They are a suitable choice for demanding metal drilling when the specified bit matches the material. The practical advantage is heat-resistant alloy construction, not immunity to wear or breakage. Correct speed, lubrication and a secure chuck grip remain essential.
Where are Bosch tools made?
Bosch manufactures across several countries, and the country of origin varies by product. Do not assume a drill bit was made in Germany because Bosch is a German company. Check the packaging or product marking for the specific item.
