Self-tapping vs. self-drilling screws (& metal + steel examples)

If you are not working in construction but need screws to do some minor repairs at home, you probably have no idea which type to choose and how they differ. There are two major types of fasteners available on the market. Those are self-tapping and self-drilling screws. 

People often buy one type instead of the other, all because of a lack of knowledge about both. To be safe with your future purchases in home improvement stores, take a look at this self-tapping vs. self-drilling screws article. It will give you all the information you need to choose the one that fulfills your needs.

What are self-tapping screws?

self-tapping screws

The main feature of self-tapping screws that makes them different from other fasteners is related to how you install them. Most fasteners require a drill, which makes the process easy. However, some cannot be placed without a pre-hole in the material you’re about to drill through. Self-tapping screws are from that range. To install them, you should first make a pilot hole in the material that will be a bit smaller than the body of a screw.

types of self-tapping screws

Self-tapping screws exist in various sizes and shapes, depending on their purpose and the object they are about to be put into. They can have blunt, pointed, or flat tips. You should choose each of them according to what material they will be used for. 

box of self-tapping screws

The one that has a flat tip is called thread-rolling. It is intended for plastic. The main feature of this screw is that it firmly rests inside the hole and leaves no extra space between the material and the fastener. While inserting the pre-hole, it can slightly deform the material. Those fasteners stay inside the hole more solidly than any other type. However, they can break or damage the plastic if you overtighten them and apply too much pressure during installation. 

The one that has a pointed tip is called thread-cutting. It is typically meant for metal and wood. The name of this fastener alludes to its main feature of creating threads inside the drilled space. Those threads serve as a path for the screw to go smoothly inside. 

Thread-cutting screws tend to remove some of the material when you disassemble them. This unfortunate issue can be resolved in two different ways. When you put the screw inside the disfigured hole again, make sure that the fastener you use is slightly larger than the previous one. 

Moreover, to avoid damage from the beginning, you can install a metal insert that will prevent any disfigurement. If you do that, you can easily fasten and unfasten an initial screw without changing its size.

What are self-tapping screws used for?

box of self-tapping white screws

Self-tapping fasteners are mostly used for metal, wood, brick, or such types of plastic as plywood, fiberglass, or polycarbonate. They are well suited for iron, aluminum, bronze, or brass. Their most common use is automotive systems or parts that need to be disassembled and put together multiple times. For example, canopies or even air-conditioning systems. 

Self-tapping fasteners are good for surfaces where you can only access one side and can’t use the rear and nut. Moreover, they are good for attaching metal to wood or securing two metal sections together.

How do self-tapping screws work

One of the main features of tapper fasteners is that they require a punch hole. Before installing them, you should drill a hole in the surface and only then put them inside. As you may notice, thread rolling fasteners do not have a pointed tip, making it impossible to drill them into an object with no holes for that purpose. 

On the other hand, thread-cutting fasteners have a sharp tip that enables them to go through material that does not have a pilot hole. However, you can still drill a hole for your convenience. If you deal with metal, which is more rigid than wood, there is no point in struggling with doing everything manually.

advantages and disadvantages of self-tapping screws

If you consider purchasing self-tapping fasteners, you can take a look at their pros and cons. It will help you make your choice easier. Regarding saving money, tapper variants are a cheap option. 

It is the best choice if you need to fasten plastic parts. You will be able to assemble and disassemble parts easily. The disadvantage of this functionality is that you can do those manipulations no more than 10 times. 

The other thing that may attract you to those fasteners is their high vibration resistance. On the other hand, tightening and managing torque is a bit challenging and requires extra effort.

Furthermore, they do not require pre-molded threads or additional time to reach full strength. If aesthetic attractiveness is what you desire, unfortunately, these fasteners cannot offer that.

What are self-drilling screws?

Self drilling steel screws

Self-drilling screws are distinguished because they do not require additional pilot holes and can be inserted immediately. It saves time, effort, and money because there is no need to buy additional drill points. It is quite advantageous for building construction, where those fasteners are most commonly used. 

You may also notice that, unlike tapper screws, self-drilling ones have a different point with a drill bit shape. Drill points are numbered from 1 to 5. The higher that number is, the more rigid steel they can penetrate. 

Self-drilling screws can also tap threads. Therefore, they can be tapped in the same way that self-tapping technology works. Unfortunately, this does not apply to tappers, and they are not self-drilled.

Differences between self-tapping screws and self-drilling screws

Self drilling screws

Now that you know what self-tapping and self-drilling fasteners are, it is time to compare them and see their differences. After you look at the following table, choosing the type you need will be easier.

Self-tapping screwsSelf-drilling screws
InstallationSelf-threading, needs a pre-holeDo not require a pilot hole
InstallationMore time consuming, requires more effortEasy and quick in installation
MaterialPlastic, wood, metal, bricksMetal to metal; wood to metal; low-density materials, metal, steel

Best self-tapping screws for steel

If you are looking for a cheap and high-quality set of self-tapping screws, KBRPARTS is just what you need. The kit contains tappers of 10 different sizes and 2 different head types: Hex and Phillips Roundheads. The first head type is strong and more stable, but the second one is simple in installation.

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It's a great assortment.

All fasteners are made of 410 stainless steel and have a black color. You will not see traces of corrosion or rust on them. Moreover, they will last longer, and you will not regret spending money on them. This kit is suitable not only for steel but also for wood, aluminum, and plastic. Suppose there are any particles left after you use them for steel. In that case, you can apply them to any other material in the future.

In case you are doing some big renovations and need a huge supply of self-tapping screws, you can buy a Stainless Steel Set that consists of 380 pieces. Like the previous option, this one is made of 410 stainless steel, which makes it highly resistant to corrosion and more durable than any other option on the market. You will rarely find a set with so many advantages. When you see one, do not hesitate to purchase it.

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best self-drilling screws for metal

Drilling screws are the best option if you want something easy to install and will last a long time. In case you need a lot of units for larger construction, you can buy a DUDSOEHO Assortment Kit that is perfect for wood and other materials present in building repairs. The fasteners in this kit are made of 410 stainless steel. It means that they are resistant to corrosion.

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DUDSOEHO
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This set includes fasteners of 16 different sizes. Those are #8 3/4″, #8 1″, #8 1-1/2″, #8 1/2″, #10 1-1/4″, #10 3/4″, #10 1″, #10 1/2″, #14 3/4″, #14 1-1/4″, #14 1″, and #14 1-1/2″. When you buy a DUDSOEHO set, there is no chance for you to struggle with finding a proper size for your repairs. Moreover, each item is silver in color. They will look attractive on any open surface if you aren’t able to keep them hidden.

All units of the kit are sorted out in a transparent box. Each size has its separate section, which means that you will easily and quickly find the right one. You can use those fasteners for wood, thick steel, metal, and plastic. 

You can buy a Small Parts Self-Drilling Set with only 50 units if you don’t need a big set of fasteners. They have a flat head and a 6-point star in the center, guaranteeing good torque resistance. Moreover, all items are made of zinc and have corrosion resistance. The screws in this set come in #10-16 sizes, which is a good variety for you to choose from. This one is a perfect option if you need a good set of screws for metal.

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Small Parts
Small Parts hit the nail on the head with this one!

best self-tapping screws for aluminum

 If you are looking for a good set of screws for aluminum, the Wenylsam set can become your kit of choice. This one is huge and consists of 420 pieces of 12 various sizes. You can use them not only for aluminum but also for wood, plastic, and steel. 

This set comes in a portable case with a few different sections for each type of screw. You will have no trouble identifying which one you need. Moreover, in one box, you will get not only a variety of sizes but the variety of heads as well. Those are wafer and hex-style heads. If you need a good set of screws for aluminum, buy Wenylsam.

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galvanized self-tapping screws

Most of the screws go through a process of galvanizing that gives them a longer life. They are submerged in zinc during this process and then cooled down. As a result, it retains a thin layer of zinc on its surface, preventing it from being easily damaged. In that way, the screw maintains its durability and long life.

If you want to buy a galvanized screw set for your home furniture, FARRAY Wood is an ideal choice. They will not break or deform, and a galvanized surface will protect them against rust and corrosion. If you want the best for your furniture, those screws should be on your shopping list.

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Metal

Screwing into softer materials is almost effortless, unlike screwing into metal. For this one, you need to follow particular steps to make the process easy without any additional complications. Here are a few steps necessary for you to stick to while drilling metal. 

How to screw into metal

  1. Prepare all necessary materials and tools.

    You will need safety glasses to protect your eyes and suitable drill bits. You should also take a lubricant that will reduce friction and clamps with which you can safely secure everything in place.

  2. Although some screws can do without pilot holes, making them for rigid materials such as metal is suggested.

    That will make the screwing easier. Therefore, drill a hole in the metal that is a bit smaller than the size of the screw. 

  3. The final step is to insert the screw.

    Start drilling at a slow speed and then slowly increase it when you see that the screw is correctly positioned in the center. Ensure you don’t use too much pressure since it tightens the fastener too much.

Will self-tapping screws go through steel?

Self-tapping fasteners can go through steel, but only if you drill the pilot hole in advance. You can use a tape measure to determine the depth and degree of a future hole. Using a larger drilling bit is better than the one you usually use for softer material. It will allow you to insert the screw much easier. If you don’t have a larger bit, you can use a regular screwdriver afterward to finish the hole.

FAQ

Are self-tapping screws better? 

If you choose between self-tapping and self-drilling fasteners, the second option is the better option. The first one is less preferred because it requires more installation time and effort to make a pilot hole. On the other hand, the self-drilling option can be drilled inside the material within a few minutes. 

Why is it called a self-tapping screw? 

The name “self-tapping fasteners” alludes to their ability to tap threads while they are inserted in a pre-drilled hole. Self-drilling ones can also create threads, but they have a different name because their main ability is to insert material that does not have holes. 

Are sheet metal screws self-tapping? 

Yes, sheet metal screws are self-tapping because they can tap the material.

Can you use self-tapping screws in wood? 

Self-tapping fasteners are suitable for various materials, including wood.