Direct Answer: Use solid carbide drills for high-volume production, hard materials and rigid CNC machines. Use HSS jobber drills for hand-held drilling, short runs and less rigid set-ups. Carbide cuts faster and lasts longer but is brittle, while HSS is tougher and costs less.
Choosing the wrong drill material costs more in broken tools than it saves on price.
Solid carbide drills and HSS jobber drills each have a place in the workshop. Carbide drills are very hard and cut faster, which suits high-volume hole production on rigid CNC machines.
HSS drills are tougher and cheaper, which suits hand-held drilling, less rigid set-ups and short runs. This guide explains the difference and how to choose.
Al Rizq supplies Supercut drill bits and other cutting tools in Dubai and across the UAE.
What Is a Solid Carbide Drill?
Solid carbide is used to make cutting tools such as drills and end mills, and it is made from tungsten carbide. It is much harder than high-speed steel, resists heat and abrasive wear well, and holds its edge for longer.
It is also brittle, so it does not tolerate rough handling, vibration or an unstable set-up.
Solid Carbide vs HSS Jobber Drills: Which Should You Choose?
The choice comes down to hardness against toughness. High-speed steel combines a high working hardness with good toughness, and HSS drills cost less than carbide drills.
Carbide is much harder, so it gives longer tool life and faster cutting data than conventional HSS. The downside of that hardness is brittleness, so a carbide cutting edge can chip or fracture in the wrong conditions.
Why Carbide Drills Fail
Most carbide failures trace back to the set-up rather than the drill. The main causes are:
- The workpiece is poorly clamped.
- The set-up is not rigid.
- The tool is a long-reach type with excessive overhang from the tool holder.
- The machine spindle is in poor condition.
Where Carbide Drills Work Best
Carbide drills are generally used for high-volume hole production, where the higher tool cost can be justified on a cost-per-part basis. For deep, high-volume holes they are often available with internal coolant ducts, which gives longer tool life and stable production.
Through-the-spindle and high-pressure coolant gives excellent chip evacuation in deeper holes. It is also the most effective way to cool the cutting edge.
Carbide is the fastest way to produce holes in a wide range of metals, thanks to higher cutting speeds and feeds. In some high nickel-chromium alloys, such as stainless steels, the hole wall can work-harden quickly, which shortens the life of any tap that follows.
Carbide can also be justified in low-volume work when the material is too hard for HSS.
Where HSS Drills Work Best
HSS drills have a very wide range of uses, from hand-held drilling to short-batch CNC machining. This comes from their toughness and lower cost. They suit less rigid applications, such as hand-held drilling and stack drilling.
They also suit deep-hole drilling where an internal coolant supply is not available. Different geometries are available for specific material grades.
Solid Carbide vs HSS Jobber Drills at a Glance
This table sums up the main differences between the two drill types.
| Factor | Solid carbide | HSS jobber |
|---|---|---|
| Hardness and tool life | Very hard; holds an edge longer | Softer; wears faster |
| Toughness | Brittle; needs a rigid set-up | Tough; tolerates less rigid set-ups |
| Speeds and feeds | Higher | Lower |
| Cost | Higher per drill; often lower per part in volume work | Lower per drill |
| Best for | High-volume production, hard materials, rigid CNC machines | Hand-held drilling, short runs, stack and deep-hole drilling without through-tool coolant |
Once you know which type suits your job, a few habits protect the drill and the finish.
Need help choosing between carbide and HSS?
Tell us your material, machine and hole size, and we will help you choose a suitable drill.
How to Get the Best Results From Solid Carbide Drills
Follow this guidance before you buy and when you set up a carbide drill:
- Know your workpiece, including the metal grade and its hardness.
- Use a rigid CNC machine with an accurate, low-runout tool holder, such as a hydraulic or shrink-fit holder, and secure work-holding. A loose or inaccurate set-up leads to noise, a poor finish and broken drills.
- Use plenty of good-quality coolant, ideally through the tool for deep holes, to cool the drill and clear chips.
- Choose the shortest flute length that does the job. A shorter drill is more rigid, which gives longer tool life and allows higher feeds.
- Avoid very long drills chosen only to allow more regrinds. They are more likely to break and can cost more in the end.
- Keep the overhang as short as possible to prevent early failure.
- Check the tool maker’s recommended parameters for your drill and material.
For a wider method of matching bits to materials, read our 6-step framework for choosing drill bits by material.
Where to Buy Drill Bits in Dubai and the UAE
Al Rizq supplies Supercut drill bits and other cutting tools in Dubai and across the UAE. Ask us about solid carbide drills and we will confirm availability and quote within 24 hours.
For the machines that run them, see our drilling machines.
Looking for drill bits in Dubai or the UAE?
See the Supercut range we supply, or ask us about solid carbide drills and we will confirm availability and quote within 24 hours.
Frequently Asked Questions
What is the difference between solid carbide and HSS drills?
Solid carbide is much harder, so it lasts longer and cuts faster, but it is brittle. HSS is tougher and costs less, which suits hand-held drilling and less rigid set-ups.
When should I use HSS jobber drills instead of carbide?
Use HSS for hand-held drilling, stack drilling, short runs and set-ups that are not rigid. It is also the better choice for deep holes where internal coolant is not available.
Why do solid carbide drills break?
Most breakages come from the set-up: poor clamping, a non-rigid machine, excessive overhang or a worn spindle. Carbide is brittle, so it needs a stable set-up.
Do solid carbide drills need coolant?
Yes. Use plenty of good-quality coolant, ideally through the tool for deep holes, to cool the drill and clear chips.
Are solid carbide drills worth the higher price?
For high-volume production, often yes, because the cost per part can be lower. For hand-held drilling or short runs, HSS is usually the better value.
Does Al Rizq supply drill bits in Dubai?
Yes. Al Rizq supplies Supercut drill bits and other cutting tools in Dubai and across the UAE. Ask us about solid carbide drills and we will confirm availability.