As an industrial tradesmen, if I talk about sheet metal screws, then this screw fastener is further divided into two categories; self-drilling, and self-tapping screws, what’s the difference between both? Do you know? Well both have totally different uses, that’s what I am going to highlight below;

The self-tapping screw has just a point on the end of it, and is meant to tap its own threads into sheet metal were there’s already a hole. Whereas, self-drilling screw can actually go through thicker metal as it can drill its own hole on the way in

The self-tapping screws are often used in appliances such as washers, and dryers, or any things with that nature where there is, or rather there are two pieces of sheet metal that are meant to be joined together, may be the body, there’s your back panel, and there’ll be big hole punched in the first panel, then a smaller hole punched in second panel.

The self-tapping screw goes through the first panel and cut its own threads into second panel. Also, you can find them sometimes on those little eclipse, there’s couple other names for them, but basically, you drill a hole in piece of sheet metal, you slide this clip on, and it acts as a nut of sorts, and you often use self-tapping screw in those clips

A self-drilling screw on other hand can go through a lot thicker metal, you wouldn’t want to use this in applications where you don’t need it, and you definitely wouldn’t want to use it with those nuts because it would just tear up the nut. However, when you’re going through thicker metal

Let’s suppose you putting small handle on small utility cart trailer, and handle have holes already punched through it, then you will be going through the tongue of trailer which has to be around 8 inch thick box cubing, here a self-tapping screw wouldn’t be enough. You’ll need something that is going to punch it to a hole, there you need to grab self-drilling screws, and it will go right through

These screws are also commonly used in installing metal roofs where you’re going metal laughs both beneath, so you don’t need to drill your own hole and use this. The self-drilling screws are highly useful when it comes to secure anything to a piece of angle iron, and you don’t want to drill out, doing nut, and bolt, and go through other hassle

Tip: For best functioning, especially if for professional works, be professional in choosing product supplier. Always approach reputable self-tapping screw fastener manufacturer who know what type of screw would be best for any specific application

Hope this brief guide help you resolve the confusion regarding both self-tapping and self-drilling screws.