38mm self drilling screws

Lastly,the type of joint being created is also an important factor to consider when selecting the correct wedge, bolt, and drill size. Different joints require different types of fasteners and drilling techniques. For example, a dowel joint may require a dowel and a countersink bit, while a lag screw joint may require a lag screw and a pilot hole. It's important to ensure that you select the correct type of fastener and drilling technique for the type of joint you are creating.

...

20mm chipboard screws typically feature a coarse thread, which allows for quick penetration into the board without causing excessive strain on the material. Their length, 20 millimeters, is ideal for most applications, providing ample depth for secure fixing without protruding through the other side. The sharp point at the tip ensures easy entry into the board, while the Phillips or Pozidriv head offers a secure grip for the driver bit, reducing the chances of slippage during installation.

...

Tek screws, named after their inventor Tek Screw Corporation, are designed with a unique thread pattern that allows them to tap their own hole in metal, wood, or composite materials. Their primary advantage lies in their ability to provide a secure hold without pre-drilling, saving time and effort on job sites. The 20-inch variant is particularly valuable due to its length, which enables it to penetrate deeper and handle heavier loads compared to shorter screws.

...