FASTENERS 101™
Drives, Heads and Threads


Fastener Variety Specifics

Fasteners come in various drive styles, each offering its own benefit to a specific application. Additionally, the head and the thread of the fastener also offer the same specifications depending upon application type.

Fastener Drives Fastener Heads Fastener Threads


Drives

There are several more drive styles available, these are the styles that you will currently find on our site. Coming soon: Spanner, HTC / One Way, Clutch, Tri-Wing & More!

phillips drive

PHILLIPS

The most common drive style. Shaped like a cross.

slotted drive

SLOTTED

A straight line cut into the center of the head.

SlottedPhillips combo Drive

SLOTTED/PHILLIPS COMBO

A drive style combining the two most popular drives for ease of use with whatever tools you have available.

square drive

SQUARE

A square shape, resists stripping out.

torx

TORX / STAR / 6 LOBE

Torx drive, also known as star drive resists stripping out and provides a more decorative drive finish.

Torx Security Screw

TORX WITH PIN / TORX TAMPER PROOF / TORX SECURITY

Torx with pin security drive can only be driven with security bits and are used to prevent tampering and theft.

SOCKET HEAD SCREW

SOCKET / ALLEN / HEX

Driven with an Allen Key, hex wrench or socket driver, socket caps are often used for decorative or automotive applications.

SOCKET / ALLEN / HEX WITH PIN SECURITY drive

SOCKET / ALLEN / HEX WITH PIN SECURITY

Driven with a special security Allen Key, hex wrench or socket driver, socket set are often used for flush or secure finish.

External Hex Head Drive

EXTERNAL HEX HEAD

While not technically a drive style, the hexagonal head is designed to be driven by a wrench.

One Way security screws

ONE WAY SECURITY

The one-way security drive style is driven in using a flat head screwdriver and cannot be easily removed.

Spanner Security Drive

SPANNER SECURITY DRIVE

Driven using a special two-point bit, also referred to as a snake eye drive.


Types of Fastener Drives | Fasteners 101

Different Common Drive Styles for Fasteners
Types of Fastener Drives Transcript

Scroll Down to Continue Reading

Bob: Welcome back to Albany County Fasteners - Fasteners 101. I'm Bob and today I want to go over the most popular drive bits.

I have here the most popular, seven types of driver, bits used day in and day out and I just want to go over the different types with some tips here on what basically, is used, each day.

So as far as deck screws go, and this is a deck screw, they come in three different drives: you can get the deck screws with Phillips drives, Square drives, and Torx (star) drives.

This one here is a square drive and I want to go over some key factors of using a square drive, which is a very common driver for deck screws, it's one of the most used. Also, a lot of people like to use the Torx drive because there's less chance of stripping.

With the square drive deck screw, if your bit is what I'll call a substandard type of bit and the bit is not properly manufactured where the head of the square drive is not flat and it doesn't sit in here tight, okay, and it has play in it, it's going to strip the screw as you drive it and then you're going to say "oh the screw is no good" or "the screw wasn't properly manufactured." I've heard all the stories already. So, I just want to point out to you if you're using a square drive that to make sure that you buy a quality bit and you'll have less issues installing your desk screws, or there could be a square drive panhead sheet metal screw, same thing: use a good square drive bit. This is very commonly used, it's one of the ones that I use. I do like it.

I also like the Torx (Star or 6-Lobe). This is a standard Torx self-drilling screw with a Torx bit, driving bit. These bits, as far as stripping the heads out, the chances are very slim to create slippage or damage to the head while you're driving the screw. It's actually a very excellent bit to drive your screws in with. It has these points which lock the bit into the head and you get a very good positive driving to drive your screw in. Especially when you're dealing with self-drillers, drilling into steel or metal. Torx is one of my favorites.

This is a Phillips flathead screw with a Phillips Drive bit. This particular one is a number three. If you buy a good Phillips bit, like the ones we sell, you'll have very little issue. The key to Phillips drivers is to make sure you're square with the actual screw. If you're square and you hold it straight and you don't try to bounce it around, off the top of the head, you'll have less chances of stripping out the head. This is one of the most common used bits out there.

Depends on your application what you're going to use it for, but if I had to choose between those three I would definitely select the Torx, if I could, or the square drive over the Phillips.

The next one I have is an (internal) hex which is basically a socket cap screw. It's a button head and I have a hex driver. The hex drivers work very well, they actually work better than a square drive (less chance of stripping out), but the only issue is that you can't get deck screws or self-drillers with a Hex Drive. Very limited and most of it (Hex Drive screws) are used in socket caps. That's where they're used.

The next one I have here is a Torx, I'm sorry this is not a Torx, this is a hex security screw. This is a security set screw with a pin in it. So, once you put this in place it's very very hard for anybody to get it out because they got no way of getting in there to grab a head or try to remove it. There's that little pin there that prevents them from putting a regular hex drive, like this one, in there. It stops them. Whereas this bit has a hole in the center of it which allows you to slide over that pin that's in the socket set screw and you'll see here I'm gonna put it in place. There you go. This is an awesome security screw if you're able to use it.

The next security screw that I have is a Torx security driver and again superior for driving screws in. This is security so, if you don't want someone to have an easy way to remove the screws, this is a good security fastener to prevent them from removing your screws. This is a superior driver so again very, very good.

This is the old-fashioned one. This is slotted head, or slotted flat head, screw with a slotted driver. The key to these is to have it so they're big enough for the head. So, like this one here, you can see that it is almost - 90% - covers the full drive and the slot has to be tight. This is not exactly perfect so if it's loose like this, that I have here, then what's going to happen is if you tilt that bit while you're driving it with a drill, chances are it's going to slip off and it's going to strip the head a little bit.

To recap: if I was to select and depending on what's available out there for the actual application and the screws you're going to be using, my first choice would be Torx. My second choice would be to use the square drive and then my third choice would be Hex and then Phillips and then you have the security screw applications. Those are limited as to where you're gonna be putting those screws. I just wanted to give you this tip and this information, so you better guide yourself as to using these drivers.

Thanks for watching.


Heads

The most common fastener heads are listed for your convenience.

bugle head

Bugle Head

A Bugle Head is similar to a flat head. This screw has a rounded section that will pull down the material instead of cutting through it as it is fastened. Distributing the pressure over a larger surface area.

button head

Button Head

A button head is a rounded head, used primarily in socket cap screws. This head sits above the installation surface.

Button Flange

Button Flange

The button flange head is like the regular button head style but with a flange or integrated washer to increase surface area during an installation.

cup (dome) head

Dome (Cup) Head

The cup head is seen almost exclusively on carriage bolts. With a square neck, this head style is made to be pulled into soft material, such as wood, and hold the bolt in place.

Fillister Head

Fillister Head

A head with a higher profile than a round head or button head. This type of screw also has a deeper drive area and is commonly used in countersunk holes.

External Hex Head

External Hex Head

External hex heads are the standard bolt head. This head is designed to be driven by a wrench and allows for high torque installations.

Hex Washer Head

Hex Washer Head

A head that is designed to be driven by a wrench with an integrated washer or flange to increase the installation surface area.

Knurled Cap

Knurled Cap

A knurled cap head style sits above the installation surface and has indents on the sides to be gripped by the thumb.

Knurled Thumb

Knurled Thumb

A knurled cap head style sits above the installation surface and has indents on the sides to be gripped by the thumb.

Smooth Cap Head

Smooth Cap Head

Like a knurled cap head style but designed to be driven by an Allen wrench or hex key. The smooth sides give it a cleaner finished look.

No Head

No Head

The head of a socket set screw, lacks a head and has an internal drive in the body of the screw itself. Designed to sit flush with the installation surface.

Flat Head

Flat Head

A flat head is can have several drive styles, designed to be drilled into a material until it sits flush with the installation surface.

Oval Head

Oval Head

Similar underside to that of a flat head screw but with a decorative rounded top. Commonly used as a finish screw in visible applications.

Pan Head

Pan Head

A screw with a rounded head (less so than a button or round head) and a flat bottom designed to sit directly on the installation surface.

Pancake Head

Pancake Head

A flat-topped screw with a wide head to sit close to flush but also have a large surface area on the installation material for grip.

Round Head

Round Head

A completely rounded head that was very popular but has become less so with the variety of heads now available.

Square Head

Square Head

a head designed to give better grip to a wrench than an external hex head.

Truss Head

Truss Head

With a flat bottom and a wider installation surface area, this screw is used where a lower profile is desired, but a strong grip is needed.

Modified Truss Head

Modified Truss Head

Like the truss head but with an integrated washer which increases the surface area of the head even more.



Threads

coarse thread screw
COARSE THREAD - UNC

Coarse threads are those with larger pitch (fewer threads per axial distance) and larger thread form relative to screw diameter. Example: 5/16-18

fine thread screw
FINE THREAD - UNF

Fine threads are those with smaller pitch (more threads per axial distance) and a smaller thread form relative to screw diameter. Example: 5/16-24


Coarse Thread Vs. Fine Thread

Coarse threads have higher thread peaks than fine threading. These threads are more durable. With a greater resistance to stripping and less need to handle them gently, coarse thread fasteners are more readily available than fine thread. They are also less susceptible to thread galling than fine thread.

Fine threads are stronger than their coarse thread equivalents. They are also much less likely to be shaken loose during vibration due to their tighter helical structure. Fine threads are also less commonly used and require more care to avoid stripping and cross-threading. Due to the increased number of rotations they require to install, they are also more likely to encounter galling upon installation. Anti-Seize Solution is recommended.


Fastener Head Stripping

There are many different drive styles available today that have improved the way screws are driven. Unfortunately, none are without flaws. Follow these guidelines to prevent your screws from stripping when installing or removing fasteners.

  • Ensure the driver is the correct size. If the driver does not fit fully into the drive recess, change the size.
  • Check the driver for damage due to over-use or mis-manufacturing. If it is not perfect, it is more likely to cause stripping. Replace the driver.
  • Make sure the drive is set fully into the drive recess. If the driver is angled, it will apply uneven torque and likely damage the drive recess.
  • Drill pilot holes in harder materials. Otherwise, the fastener may heat up and seize which can cause stripping or snapping to occur.
  • Make sure to drive smoothly and evenly until the fastener reaches the desired stopping point. Do not over-tighten as this may cause excess torque to be applied to the drive and cause snapping or stripping as well.
  • In scenarios where both metric and standard drive sizes exist (external and internal hex) make sure the correct size is used. Most sizes do not correlate directly and the gap between the fastener and drive may cause rounding or stripping to occur.

*Note: The Phillips drive style should not be used in high torque applications. It is more likely to cam out and another head style should be used.


Want to learn more about Fasteners? Check out our Weekly Blog for new posts every Monday!