What Are Self-Tapping Screws
In any type of construction job, knowing the different kinds of screws available is essential. Certain projects require specific fasteners and self-tapping screws are one of the many options you can use. These fasteners have cutting threads on their shanks and sharp-pointed or drill pointed tips that allow them to drive into a material and cut their own mating threads unlike a machine screw which requires a nut. Many contractors love using these fasteners because they make attaching materials like wood so much easier.
Understanding screws and their uses lets you work faster and more efficiently. At All Points Fasteners, we distribute a variety of self-tapping screws and our knowledgeable team is always happy to provide information on how to use our products. Whether you’re working on HVAC jobs, installing gutters or roofing a house, we’ve got the fasteners you need to get the job done.
What Is a Deck Screw?
Deck screws are a type of wood screw with a specific coating on them for working with treated wood. Other fasteners can react to the natural resins in lumber, causing stains over time. Using deck screws helps prevent this reaction thanks to the chemical makeup of their outer layer. These fasteners are ideal for protecting the integrity and appearance of your wood decking.
Projects where wood screws are useful include:
- Putting together decks
- Building cabinets or furniture
- Making assemblies with plywood
True wood screws typically have an unthreaded area of the shank below the head, which allows for a tighter grip since the screw can spin freely in the outer layer of material and impart more tension at the bottom. Wood screws are self-tapping as well, tapping their own thread into the wood, making them perfect for any woodworking job.
A type 17 point, also known as an auger point, is a feature on many wood screws which eliminates the need to drill a small pilot hole before inserting your fastener. This allows the threads to begin cutting without having to displace material to accommodate the shank’s diameter. Power drills, rather than impact drills, are best to install these fasteners.
All Points Fasteners has a variety of self-tapping wood screws to choose from. Our reliable customer service representatives know how to assist you in finding what you need.
Self-Drilling Screws for Wood
Many people use the terms self-tapping and self-drilling interchangeably, but these labels have different meanings. Self-drilling screws are fasteners with drill bit tips, manufactured mainly for metal to metal applications. Their threads ALSO make them self-tapping screws since their threads tap their own mating threads into the material. There are only two type of self drilling screws that are designed to be used with wood.
- reduced points – very small drill bit tips that drill smaller diameter holes than the outside diameter of the screw. This allows the larger outside thread to tap in to the wood. Normal drill bit tips will drill a hole basically the same width as the diameter of the outside thread of the screw, which will allow the screw to pull out of the material since the thread can’t tap.
- reamer tek screws – wood to metal screws. These screws have small ‘wings’ above the tip of the self-drilling screw which will ‘ream’ out the wood so that the threads of the screw won’t get bound up by the wood before the screw hits the metal. Once the screw starts drilling through the metal, the ‘wings’ will break off.
Buy Self-Tapping Wood Screws in the Quantity You Need
Whether you’re looking for self-drilling wood screws or another type of self-tapping screw, All Points Fasteners can help you find what you need with our large selection. We will work diligently to build a relationship with you throughout your experience with us.
You can fill out our contact form today to get a customized quote for the fasteners you need.
It’s Not So Difficult Ordering Self-Tapping Screws!
So you picked a self-tapping screw off a job site and it was just what you have been looking for but it didn’t come in a box that was labeled – it was just sitting there on the floor. What do you do? How can you ask for something when you’re not really sure what to ask for? The nice thing is that it isn’t so difficult if you know what dimensions to measure when you are asking your fastener sales representative to help you.
First describe the head. Is it a…?
- Hex Washer Head
- Hex washer head with a neoprene washer attached
- Modified Truss Head
- Oval Head
- Pan Head
- Bugle Head
- Pancake Head
There are other style heads available but these are the most common head styles that you should know. Once you can identify the head style that you are looking for, it makes things much easier.
To identify the shank size of the screw, it’s much easier if your screw is a hex head. When considering the shank size, think dress size. The smaller the number, the thinner the shank. The bigger the number, the thicker the shank.
The standard for the industry is:
• 1/4″ Hex Head = #6 or #7 or #8 shank size
• 5/16″ Hex Head = #10 or #12 shank size
• 3/8″ Hex Head = #14 shank size
Of course there always have to be exceptions just to keep things interesting.
In our case, we have needlepoint screws (aka zip screws) developed especially for the gutter industry with have high profile 1/4″ hex head but #10 washers and #10 body shanks. In the 70’s and 80’s, standard #8 screws worked fine for the gutter industry but when the quality of the wood used for homes changed, it was necessary to increase the thickness of the shanks so that the screws wouldn’t snap when hitting knots in the wood. We also added a filet underneath the head to give the screw a little extra strength.
Next, there is TPI or threads per inch to consider. As a rule of thumb, the less threads per inch, the screw is intended to be used in wood. The more TPI, the screw is meant for metal or metal studs. These are sometimes called out as ‘coarse threaded’ or ‘fine threaded’ screws. If you try and use a coarse threaded screw in metal studs or hard woods, the quality of the screw can’t really be blamed when it snaps although that happens all the time. It is simply misapplication and the more you know what screws were made for what applications, the less problems you will have when using your screws.
Now we get to the points of the screws.
Does the point look like a pencil point?
Does the point look like a drill bit tip?
There are other type points like Type 17’s used with woods and others but the two listed above are the most common.
And lastly, you should remember to state the plating that you need. Zinc plating is most common with under normal situations will last you about two years on average. Hot dipped galvanized is generally five years. But these are old school type plating. We have started stocking Dacronized®, ceramic type plating, which we normally have stocked in 500, 1000 and 1200 hour salt spray tested. They give you extra protection and even are available with the heads painted as well to match exterior applications.
When you are looking at a label on a box, the screws will generally be labeled something like “8-18×1 HWH SDS Z/P”. This would translate to #8
shank, 18 TPI by 1 inch long, hex washer head, self drilling screw (tek type point) zinc plated.
This is not everything that there is to know about self-tapping screws, zip screws and tek screws included, but it will give you a good baseline to start!
Not Just Zip Screws and Tek Screws!
Having been in the fastener industry for contractors since 1986 selling zip screws and tek screws you would think there would be nothing new to learn. Wrong! Although we specialize in screws mainly used by the Heating and Air Conditioning and Gutter industries , more and more I am hearing from OEM’S or engineers who are desperately looking for screws that don’t exist. They needs head diameter’s that are smaller so that they will fit in between narrow grooves, points that will penetrate hard plastic, then go through 30 gauge steel and then tap into stucco then into wood. And they are being used outdoors in the snow but should be rust proof but not as expensive as stainless steel. And all in the same screw! It’s a wonder I have a hair left on my head!
In years past, designer screws were a source of frustration for me because one of my contractors would pick up a screw that he really liked on a job site and then want me to locate a source for them. After many hours, maybe days, of diligent searching, I would finally find out that someone like a major hotel chain had the screws made especially for them to install the cabinets in their hotels and getting the same screws with the same dimensions was never going to happen.
Well the good news is that some manufacturers have changed their willingness to do smaller orders so that the chance of having these ‘designer screws’ manufactured is much higher now than it was in the past. Within recent months, we have been successful in procuring parts that in the past would have been impossible to supply. Of course, there are still minimums to be met but instead of having to order containers of screws in order to get the manufacturers interested, we can get away with a pallet or two. Good news for some but still not low enough for others.
Still, there are many more options available to choose from than there were 20 years ago, starting with coatings to keep screws from rusting as quickly. Take a look at our ceramic coated zip screws, available which with painted heads as well. These parts work great in areas where weather conditions are moist. We will soon be supplying needlepoint screws which are stainless steel as well as ceramic coated which will bring increased rust resistance.
K-Lathe aka Modified Truss aka Round Washer Head
The Round Washer Head design, which can also be known as wafer head screws, K-Lathe screws and modified truss screws, could quite possibly be the most multipurpose head design offered. It combines the benefits of the Pan Head design but has an attached washer built on to the head to increase head diameter. This helps prevent over-driving in softwoods.
General cabinet assembly, installation, hinges, metal drawer slides, wooden drawer guides, attaching lights and brackets are just a few applications where the Round Washer Head design is used. The addition of the washer provides maximum bearing surface to allow for “over-driving” the screw to tighten those stubborn joints easily These Screws are also self tapping screws in that they tap their own mating threads and do not need female threaded inserts like machine screws.
It was originally designed for the construction industry to attach wood lathe and metal framing to 20 to 25 gauge steel studs. They also can be known as plymetal because they can be used to attach plywood to metal. The large wafer head sinks into the plywood and has a large bearing surface The length is measured from the top of the head.
They are available in Philips drive as well as square drive, which is occasionally referred to as Robertson drive. They are readily available in stainless and well as carbon steel and with plain or painted heads.
Also known as:
- Round Washer Head Needlepoint
- Wafer Head
- K-Lathe Screws
Sharp point – zip screws, or self-drilling – tek type screws, these screws are also self-tapping screws as they tap their own threads into the materials they are used with and do not need to be used with a pre-threaded mate such as a nut or insert.