Basics of metal drilling

Drilling, in addition to cutting, is another way of processing metal into a finished product. When drilling into metal, chips (swarf) are produced and move upward and away from the tip of the drill bit as it cuts into the metal. This works well until the chips are not properly evacuated or the hole becomes too deep, causing clogging. Cutting fluid can help with this issue, and it also extends the tool’s lifespan by cooling and lubricating it. Coolant can be supplied through internal channels via the hollow core of the drill bit.

CNC drilling machine

In computer-controlled machining systems (CNC), a process called peck drilling is used. This drilling method prevents chip buildup when drilling deep holes and thus avoids clogging. Peck drilling involves drilling partially into the workpiece—typically up to five times the drill diameter—and then retracting the tool to the surface. This is repeated until the hole is completed.

Magnetic drilling machine

When the workpiece cannot be brought to a CNC machine, a magnetic drilling machine can be used. Its base allows drilling in a horizontal position. These machines are widely used in construction, manufacturing, maritime, and the oil and gas industry. In the oil and gas industry, pneumatic magnetic drills are used to prevent sparks, as well as special pipe-mounted magnetic drills that can be attached to pipes of various sizes. Heavy-duty plate drilling machines provide high-quality solutions in steel construction, bridge building, shipbuilding, and various areas of the construction sector.

In addition to CNC and magnetic drilling machines, there are other types of drilling machines, such as belt-driven, gear-driven, radial, high-speed variator, and FloTT drilling machines. Each drilling machine consists of several components, each performing its own function. Among the most important elements are drilling units with drill bits.

Drill bits

In the past, standard dry HSS core drill bits were used for metal drilling, but since 1988 they have been almost entirely replaced by drill bits with internal coolant. Since 2004, the use of solid carbide drill bits or KSEM cutting tools has also become possible.

Drilling units for internal coolant drill bits or carbide drill bits

Depending on the specific application in a peck drilling line, one to three drilling units are used. Some manufacturers also offer drilling units with tool changers.

Drilling units for internal coolant drill bits

For the use of HSS drill bits with internal coolant, a spindle speed of up to 800 rpm and a power output of up to 7.5 kW is sufficient. This option is cost-effective and suitable for many systems. For proper cooling and lubrication at the cutting edge, a coolant supply with at least 6 bar pressure is required.

Drilling units for KSEM carbide drill bits or solid carbide drill bits

For the use of KSEM carbide drills or solid carbide drills, high spindle speeds and high power are required. A speed of over 2500 rpm combined with high torque is necessary. Very stable machines with good workpiece clamping are also required.

Buying a drilling machine can be a big challenge, especially if you are not familiar with the differences between them. Call us and we will be happy to advise you according to your needs to the best of our ability.