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6 Reasons This 3-in-1 Cobalt Drill Bit Set Drills, Cuts and Slots With One Tool
Need a slot, not just a hole?
You drill the hole — and then the job needs a slot. So you swap tools, reach for a jigsaw or file, and the neat start turns into a messy finish.
A standard bit can also skate across smooth surfaces and dull quickly in tougher material.
What if one bit could drill the hole, then cut sideways to open it into a slot?
Meet the 3-in-1 M35 Cobalt Twist Drill Bit Set: six bits from 3–8 mm with serrated side-cutting edges and a 135° split point. Here are six reasons DIYers are adding it to their toolbox.
1. One Bit Drills, Saws and Slots
The bit has serrated side edges, so after drilling you can apply gentle sideways pressure and cut a slot — no jigsaw swap needed.
- Drill a pilot hole, then slot sideways
- Fewer tool changes mid-job
- Handy for adjustment slots and cut-outs
2. M35 Cobalt Steel Built for Heat and Wear
The bits are made from M35 cobalt high-speed steel (listed at about 5% cobalt), chosen to resist heat and stay sharp longer than standard HSS.
- Designed for heat and wear resistance
- Intended to hold an edge through repeated use
- Suited to harder materials than basic bits
3. A 135° Split Point Helps Stop Skating
On smooth surfaces, ordinary bits wander before they bite. The 135° split point is designed to start cleanly and stay where you put it.
- More accurate starts, no centre punch needed
- Less walking on smooth surfaces
- Cleaner entry holes
4. For Wood, Aluminium and Plastic
One set covers a range of everyday materials: solid wood and boards, plastic, aluminium and thin sheet metal.
- Solid wood, plywood, MDF and particle board
- Plastic plates and aluminium alloy
- Thin sheet metal
5. Six Sizes From 3 mm to 8 mm
The six-piece set covers 3, 4, 5, 6, 6.5 and 8 mm and uses a universal round shank that fits standard drill chucks.
| Pieces | 6 |
| Sizes | 3 / 4 / 5 / 6 / 6.5 / 8 mm |
| Lengths | 60 / 70 / 80 / 85 / 87 / 92 mm |
| Material | M35 cobalt HSS (about 5% cobalt) |
| Point | 135° split point |
| Shank | Round, fits standard chucks |
6. Made for DIY, Workshop and Repair Jobs
If you drill and fit things around the house or workshop, this is a set you will reach for often.
- Furniture and woodwork: slots and pilot holes
- Aluminium, plastic and thin sheet metal: brackets, panels, trim
- Repairs: enlarge or elongate existing holes
- Workshop: a compact set for everyday drilling
How to use (3 simple steps)
Choose a size and tighten the round shank in a standard drill chuck.
Drill straight through at a steady speed.
Apply gentle sideways pressure to cut a slot with the serrated edges.
Wear eye protection, clamp your work, and avoid heavy structural steel. Follow your drill’s instructions.
Why choose this drill bit set?
| Feature | This drill bit set | Standard HSS bits |
|---|---|---|
| Drill and slot with one bit | ✔ Serrated side edges | ✘ Drill only |
| Heat and wear resistance | ✔ M35 cobalt steel | Varies by steel |
| Starts without skating | ✔ 135° split point | Often wanders |
| Wood, boards, plastic, aluminium, thin metal | ✔ Yes | Varies |
| Sizes in the set | ✔ 6 (3–8 mm) | Varies |
Common questions
What materials can I use it on?
It is used on solid wood and boards, plastic, aluminium alloy and thin sheet metal. It is not meant for heavy structural steel.
Will it fit my drill?
It has a universal round shank intended to fit standard drill chucks. Check your chuck capacity.
How do I cut a slot?
Drill a pilot hole first, then apply gentle sideways pressure so the serrated edges cut laterally.
Does it overheat?
M35 cobalt steel is designed to resist heat better than standard HSS. Use moderate speed, back out to clear chips, and let the bit cool as needed.
Which sizes are included?
Six bits: 3, 4, 5, 6, 6.5 and 8 mm.
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3-in-1 M35 Cobalt Twist Drill Bit Set (6 Pcs)
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