HSS Ground Jobber Drill Bit Set 1-10mm - 15 Pieces

HSS Ground Jobber Drill Bit Set

The HSS Ground Jobber Drill Bit Set is a 15-piece selection of the most commonly used HSS metal drill bit sizes, covering 1.5mm to 10mm in a single weatherproof case. Each bit is fully ground from solid high speed steel and manufactured to DIN 338, the recognised standard for jobber drill geometry. The 135° quick-start split point eliminates the need to pre-drill a pilot hole before drilling into metal, preventing the bit from drifting on contact with the material surface and reducing the time needed to start each hole accurately. The set covers steel, aluminium, cast iron, plastics, and non-ferrous metals, making it a practical general-purpose metal drilling kit for trade and site use. The weatherproof case keeps the full set organised, protected, and ready to use.

Why Choose the HSS Ground Jobber Drill Bit Set?

• 135° quick-start split point: The split point geometry allows the bit to locate and start drilling immediately on contact with the material surface, without the bit walking or drifting. This eliminates the pre-drilling step that a standard point requires, saving time on repetitive drilling tasks across metal, aluminium, and plastics.

• Fully ground from solid HSS: Each bit is ground from a single piece of high speed steel rather than rolled or formed. Ground bits hold their geometry more precisely and maintain dimensional accuracy across more drilling cycles than non-ground alternatives.

• DIN 338 manufacture: DIN 338 is the internationally recognised standard for jobber drill bit dimensions and geometry. Conformance to this standard confirms the bits are manufactured to consistent, verifiable tolerances rather than to an unspecified internal standard.

• High heat resistance: HSS retains its hardness and cutting performance at elevated temperatures generated during metal drilling, where cheaper carbon steel bits soften and lose their edge. This makes HSS the correct material choice for sustained metal drilling.

• 15-piece coverage from 1.5mm to 10mm: The set includes two each of the three smallest sizes (1.5mm, 2.0mm, and 2.5mm) and one each of all larger sizes up to 10mm, reflecting the higher consumption rate of smaller bits in everyday trade use.

• Weatherproof case: The robust case keeps the full set organised by size, protects the bits during transport and storage, and is built to withstand site conditions where standard plastic cases fail.

What's Included

• 2 x 1.5mm x 40mm HSS ground jobber drill bit

• 2 x 2.0mm x 49mm HSS ground jobber drill bit

• 2 x 2.5mm x 57mm HSS ground jobber drill bit

• 1 x 3.0mm x 61mm HSS ground jobber drill bit

• 1 x 3.2mm x 65mm HSS ground jobber drill bit

• 1 x 3.5mm x 70mm HSS ground jobber drill bit

• 1 x 4.0mm x 75mm HSS ground jobber drill bit

• 1 x 4.5mm x 80mm HSS ground jobber drill bit

• 1 x 5.0mm x 86mm HSS ground jobber drill bit

• 1 x 6.0mm x 93mm HSS ground jobber drill bit

• 1 x 8.0mm x 117mm HSS ground jobber drill bit

• 1 x 10.0mm x 133mm HSS ground jobber drill bit

• 1 x Weatherproof storage case

 Specifications

Compatibility

Who Is This For?

This drill bit set is for electricians, plumbers, mechanical engineers, fabricators, metalworkers, general contractors, and site operatives who regularly drill into metal, aluminium, plastics, and non-ferrous materials as part of their daily work. The 1.5mm to 10mm range covers the vast majority of general trade drilling tasks, and the 15-piece selection with duplicate smaller sizes makes this set suited to both occasional and high-volume users.

Typical Applications

• Drilling pilot holes and fixing holes in steel sections and plates

• Drilling aluminium profiles, extrusions, and sheet material

• Drilling through cast iron components and fixings

• Hole drilling in plastics and composite materials on site and in workshop

• General maintenance and facilities management drilling across mixed materials

• Electricians drilling through steel back boxes, conduit brackets, and cable management

• Plumbers drilling through copper, brass, and non-ferrous fittings and supports

How to Use

1. Select the correct bit diameter for the task and remove it from the case.

2. Fit the straight shank securely into the drill chuck and tighten fully before operating.

3. Mark the drilling position clearly. The 135° split point will self-locate on contact with the surface, eliminating drift without a centre punch on most materials.

4. Select an appropriate speed for the material. Higher speeds suit smaller diameters and softer materials. Lower speeds suit larger diameters and harder materials such as cast iron.

5. Apply steady forward pressure and drill at a consistent speed throughout.

6. Use cutting fluid or oil when drilling steel and cast iron to reduce heat build-up and extend bit life.

7. Clear swarf regularly during drilling, particularly in deeper holes.

8. Return the bit to its correct slot in the case after use to keep the set complete and organised.

Safety

• Always wear eye protection when drilling metal. Swarf and metal particles are ejected at speed and present a serious eye hazard.

• Secure the workpiece in a vice or with clamps before drilling. Unsecured metal can rotate suddenly when the drill breaks through, causing injury.

• Allow the bit to cool before handling after drilling. HSS bits retain heat after sustained use and can cause burns.

• Inspect bits before use for damage, blunting, or deformation. A damaged bit should be removed from service.

• Do not use these bits in masonry or concrete. Using an HSS bit in masonry will damage the bit immediately and risks tool failure.

Maintenance

• Return each bit to its numbered slot in the case after use. A disorganised set leads to damaged tips and wasted time locating the correct size.

• Apply a light coat of oil to the bits periodically to prevent surface corrosion, particularly in damp site environments.

• Inspect cutting edges regularly. A blunt bit requires excessive pressure to cut, generates more heat, and produces less accurate holes.

• Keep the case closed and latched during transport to prevent bits from moving and damaging each other.

Frequently Asked Questions

Q: What does DIN 338 mean and why does it matter?

 A: DIN 338 is the internationally recognised standard for jobber drill bit dimensions, specifying the geometry, tolerances, and proportions of the bit including flute length, shank diameter, and point angle. Bits manufactured to DIN 338 are dimensionally consistent and interchangeable with other DIN 338 compliant tooling. When a bit is described as DIN 338, it confirms it has been manufactured to verifiable engineering standards rather than to an unspecified internal specification.

Q: What is a 135° split point and why is it better than a standard point?

 A: A standard drill bit has a conventional conical point that tends to walk or drift across a smooth surface before it starts to cut, requiring a centre punch mark to locate the hole accurately. A 135° split point has a modified tip geometry that cuts immediately on contact with the material surface, self-locating without drifting and eliminating the need to pre-drill a pilot hole in most applications. This saves time on repetitive drilling tasks and improves hole position accuracy.

Q: What materials can I drill with these bits?

 A: These bits are suited to steel, aluminium, cast iron, plastics, and non-ferrous metals. They can also be used in wood for general-purpose drilling. They are not suitable for masonry, concrete, or hardened steel. For stainless steel and high-alloy steels, cobalt HSS bits are the correct choice.

Q: Why does the set include two each of the three smallest sizes?

 A: The 1.5mm, 2.0mm, and 2.5mm bits are the most frequently used sizes in everyday trade work and are the most likely to wear or break in normal use. Including two of each means the set remains complete and useful for longer before any individual size needs replacing.

Q: What is the difference between ground and rolled HSS drill bits?

 A: Ground bits are machined from solid HSS material, which produces precise cutting edges, consistent geometry, and a smooth finish on the flute surfaces. Rolled bits are formed from HSS strip steel, which is a faster and cheaper manufacturing process but results in less precise geometry and rougher flute surfaces. Ground bits hold their tolerances better, maintain their cutting performance for longer, and produce more accurate holes.

Q: Can I use these bits in a cordless drill as well as a mains drill?

 A: Yes. The straight shank fits any standard keyed or keyless chuck. These bits work in cordless drills, mains corded drills, and pillar drills. For best results in harder materials, use a mains drill where consistent speed under load is more easily maintained.

Q: Why buy the HSS Ground Jobber Drill Bit Set from CMT Group?

 A: CMT Group has supplied construction and trade professionals across the UK since 2010. The HSS Ground Jobber Drill Bit Set is held in stock for next working day delivery on orders placed online by 7pm. Trade account holders benefit from agreed contract pricing, full order visibility, and live delivery tracking through our EDGE procurement portal. Order online at cmt.co.uk.