When drilling holes through metal, you always dial the speed down on your drill or drill press compared to what you'd set it at to put holes in wood. That's because with a twist bit, the heat generated by metal-on-metal friction can dull the bit and result in poor cutting quality.

An alternative metal drilling process uses a bit that doesn't have a cutting edge at all. Called friction drilling, form drilling, flow drilling or thermal drilling, the process uses a conical bit, spun at high speeds and applied with high pressure, that relies on friction itself to bore through the material. Take a look:

As you can see, the extra material displaced by the bit provides more surface area to tap, resulting in more meat for a fastener to bite into. It also obviates the need to insert a bushing or affix a weld nut, reducing production time and materials. And the process does not produce shavings, meaning the operator does not have to spend time cleaning the work area. Just drill, tap and fasten.

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Friction drilling, by the way, is not a new technique; it was first dreamt up in the 1920s, around the same time that the high-heat-withstanding cemented carbide necessary to produce the bit was developed. Nor is it some exotic NASA-level production method; it's used in bicycle frames, and companies like France's Mavic use friction drilling to produce their Ksyrium wheels, creating rims that the spoke nipples thread directly into. The gent in this vid below reckons the process makes their wheels 20% more rigid and increases their resistance to fatigue stress by a factor of four:

For applications where the rolled collar produced on the surface is not desireable, bits with cutting surfaces located above the cone (shown below) exist. After the hole is bored, the extra material up top is trimmed away. These presumably do produce shavings, as the cut material has to go somewhere.

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There is also a technique that makes the procedure even faster. Tooling companies like the UK's Quantum use flow drilling screws/bolts, whereby the tip of the screw itself is actually the bit, and the threads further up do the tapping. This means that the drilling, tapping and fastening are all done in a single step (though there's presumably something lost in set-up time):

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You can learn more about friction drilling here and here.