Let’s Talk About Screws

Screws are amazing fasteners. Stronger than nails and easy to install/reinstall, they look similar to bolts. Similar applications may require a screw and/or a bolt. Typically, a bolt pairs with a nut or washer and may or may not have a point or tapered end.

So let’s talk about screws! When we’re thinking of screws, we generally think of threaded metal fasteners with tapered ends that allow them to be driven into a material. Generally speaking, screws and nuts do not pair up. Instead, the end of the screw remains embedded in the application material. As it rotates, the screw’s thread create a new thread in a material as it turns. Alternately, screws can be drilled into preformed holes.

Did you know that screws are considered one of the six simple machines? Considered some of the first machines ever invented, the six simple machines include the wheel and axle, levers, ramps, pulleys, wedges, and, you guessed it, screws.

Screw Types

There are a wide variety of screws and screw applications.

• Self-Tapping (or Self-Drilling) Screw: These pointed screws have sharp cutting threads that tap a hole during installation. Self-tapping screws quickly drill into metal or wood.

• Socket Screw, also known as an Allen Head Screw: These screws have an internal hex drive built into the head. Socket screws fasten machine parts. The name “Allen” comes from the Allen Manufacturing Company in Hartford, Connecticut. The company trademarked the name in 1943. Although the company no longer exists today, the name stuck.

• Machine Screw: Typically, machine screws do not have a point. Often made of brass or steel, machine screws fasten metal parts together.

• Weld Screw: These are screws that are welded into place. A wide variety of applications, including construction, automotive, HVAC, and agriculture, utilize weld screws.

• Sheet Metal Screw: Fully threaded and pointed, sheet metal screws cut through sheet metal.

At Fastco, we manufacture a wide variety of screws with a various head designs (including socket, hex, Phillips Head, and 6-lobe), threads (including MAThread, Lockthread, interrupted threads, paint-cutting threads, and standard threads), and points (including MATpoint, dog points, and p-points).

Learn more about how we can meet your fastener screw needs and send us a quote today!

What are Studs (the Fastening Kind)?

In short, a stud is a threaded rod or bar. They resemble screws and bolts, except that they do not (typically) have heads. Generally, fastening studs are permanent fixtures that can work with or without nuts, although they often involve the use of a nut. They are often welded, swaged or bonded to attach. If welded, they may have a small head to make this feasible.

Standard Stud Features vs Bolts and Screws

However, the lack of head is the most unique feature of a stud, but there are other features that are often true of studs vs. bolts or screws.

Studs are often larger than bolts and screws. Used in assembling heavy machinery and materials such as turbines or tanks, studs can be manually installed because they do not require external force to be torqued down.

Bolts and screws have rotational force applied to them along with linear force. Studs, on the other hand, do not have a rotational force applied. Studs do not have stretching on their threads and can produce a repeatable clamping force. As a result, they last longer.

Different Types of Studs

Studs can be fully threaded or have threads on one end with an unthreaded end, or they may be double-ended and threaded on both sides of an unthreaded center.

Among the different types of studs are:

• Fully-Threaded Studs (These do not typically have a chamfered end)

• Tap-End Studs (These have unequal length threads on either end of a non-threaded center. There is typically a tap end and nut end. The tap end may have some kind of point.

• Double-End Studs (Studs with equal length threads on either end of the non-threaded center. One or both ends attach with a nut.)

  

   

• Flange Studs (These fully-threaded studs have chamfered ends used in flange connections)

• Welding Studs (These have single-sided threads that pair with a nut. The unthreaded side is welded into place)

Need a stud manufactured? Contact us today and send us a request for a quote.

What are mechanical fastening pins and what do they do?

In the world of fasteners, pins are one of the most basic looking components. Pins are unthreaded, usually cylindrical. Their purpose is to “keep machine parts in proper alignment or fasten them together,” according to Britannica. These are known as mechanical fastening pins, not to be confused with the pins used to hold fabric while sewing or push pins that you use to tack up paper products to corkboards.

More or less, mechanical fastening pins fall into two categories:

They rely on friction to hold them in place.

This includes most types of pins, from dowel pins to grooved pins to fetter and knurled pins and even spring pins. The more solid the pin, the more precisely it holds components and the more strength it has. On the flip side, more compliant pins like spring pins are easier to insert and more tolerant of dimensional variations in holes.

They have some form of positive locking feature.

This would include split pins and lynch pins. Since these pins do not rely on friction alone, they are easy to assemble and disassemble.

Among these groups, there are a myriad of pins, from solid pins to grooved and slotted pins to coiled and spring pins. These pin types all have all have distinctive appearances as well as varying functions. At Fastco, we manufacture primarily solid pins, as these parts fit the cold forming process well. Spring and coiled pins are better suited for a stamper or caster.

Types of Mechanical Fastening Pins

Some examples of pins that we manufacture at Fastco include:

• Clevis Pins (these fasten a u-shaped device together with the help of a cotter pin)

• Dowel Pins (a simple solid cylinder that is inserted into a preformed hole)

• Hinge Pins (a pin that holds to parts together so that one can swing relative to the other)

• Locating Pins (used to locate an item on a fixture or to align two pieces of the fixture)

• Weld Pins (pins that are welded into place)

• Fetter/Knurled Pins (pins that have a fetter or a knurl)

Interested in learning more about what we can do for you? Contact our sales team today!

Is a Rivet the Same as a Pin?

Pre-assembly, rivets look a lot like pins. In fact, this is readily stated in most definitions. TWI writes that “A rivet is a mechanical fastener composed of a head on one end and a cylindrical stem on another (called the tail) which has the appearance of a metal pin.” In other words, rivets, like pins, are unthreaded. But how rivets work and are used in applications differs from pins.

But the most important feature of the rivet is it’s permanence in an application. Their purpose is similar to that of a nut and bolt combination. But while you can easily disassemble and reassemble a nut and bolt, rivets cannot be removed without be broken or damaged. They are designed to hold together permanent joints, similar to welding applications. In other words, rivets are installed to stay.

How do Rivets Work?

The rivet is inserted into a punched or drilled hole. The pre-formed rivet head (or factory head) holds it in place and another head (the shop head) is formed from the tail, by a process called upsetting or bucking. In other words, it’s deformed, expanding to about 1.5 times the diameter of the shaft. The shop head (or buck tail) is flatter than the other head and holds the rivet permanently in place.

Rivets offer some advantages over bolts and nuts. They can resist vibration without loosening and secure joints with short clamp lengths. Rivets are also a fairly versatile fastener, typically less expensive than bolts and screws with quick and low cost assembly options.

What are the Different Types of Rivets?

There are a wide variety of rivets, including solid rivets, one of the oldest types of rivets, dating back to the Bronze Age.

Another common, easy to install rivet is the blind rivet. These rivets are hollow (typically known as pop rivets) or semi-tubular and used on applications where it is not possible to access the rear side of the parts that are being joined.

At Fastco, we specialize in semi-tubular and solid rivets, including:

• Shoulder rivets (semi-tubular or solid rivets with a shoulder under the head)
• Countersunk or flat rivets (used in countersunk holes, these rivets sit flush with the surface)
• Brake lining / clutch facing rivets (both types have flat, chamfered, countersunk heads to provide a smooth surface after install)

If you want to know more about what make, give us a call at 616-389-1402 or 616-389-1409. You can also use our RFQ form to send a quote or email us at [email protected].

What is a Bolt?

I’m glad you asked. If you search Google, you’ll find a lot of different answers. For one, Fastener Engineering calls a bolt “a mechanical fastener with a threaded shaft” while simultaneously stating that this same description can be used to define a screw.

Function: Part of a Fastening Team

Merriam Webster defines a bolt as “a metal rod or pin for fastening objects together that usually has a head at one end and a screw thread at the other and is secured by a nut.” In other words, a bolt is only one part of a fastening team, typically paired with a nut or sometimes a washer. With this definition, any fastener that does not require a nut to secure it would not be a bolt.

This definition uses the function of the part to define it, which is probably the most simple and accurate definition. But there may be other ways to define what is and is not a bolt. Specifically, there are certain features that we associate primarily with bolts.

Features: Heads, Shanks, and More

One of those features is (typically) a lack of point. In fact, Cambridge Dictionary specifically includes this in the definition, saying a bolt is “a screw-like metal object without a point, used with a nut to fasten things together.” It should be noted that this definition does not include special bolts, which may have features like dog points, MATpoints, and P-points.

In addition to lacking a point, bolts typically have only a partially threaded shaft. This unthreaded feature is called the shank (or sometimes shoulder). The shank creates an area on the bolt that is stronger and less elastic, less likely to sheer. It can also provide more versatility to the function, including acting an area for something attached to the bolt to move. Again, though, this is not true of all bolts, but would apply more to standard bolts.

Head shape is another defining feature of bolts. Unlike studs, bolts always have heads. Their most common head shape is a hexagon, as this provides flat surfaces for tools to apply torque while fastening. There are also square-head, hex flanged-head (basically a hex with a ring around it), round-head, and pan-head bolts.

Bolt Types

Other common bolt types include:

•  – Carriage bolts (dome-shaped head with a square shoulder just below the head),
•  – Stake bolts (a round-head with a knurled shoulder),
•  – Clinch bolts (bolts with a locking feature under the head that is secured by a punching force), and
•  – Weld bolts (bolts with heads that are welded into place via some type of projection or weld ring).

As you can see, defining a bolt can be tricky. You might find that what some call a bolt may actually be more stud- or screw-like in appearance. But if it functions like a bolt (i.e. has a head and fastens objects together along with a nut), then it’s probably safe to call it that. Either way, we’ll make the part for you. Send us a request for a quote today.