Imagining working on a construction or a manufacturing project without having washers by your side is foolish. It is a piece of hardware manufacturers often use with threaded fasteners such as screws or bolts. However, their functions and applications depend on the type of washer you use for your project.
Several types of washers are differentiated based on their shapes, sizes, materials, and functions. This article will discuss three major types of washers that are further categorized into various subtypes. So, let’s step into the post without further ado!
What are Washers?
Washers are small thin plates of different shapes with a hole in the center, mainly used to distribute the force of threaded fasteners. Typically, they are located between the surface and screws to act as spacers.
In addition, washers play a significant role in preventing corrosion and leakages in some cases. Apart from this, some washers are designed to absorb the vibrations of machines or equipment. Due to these characteristics, washers are essential in hardware to meet construction and manufacturing requirements.
What are the Types of Washers?
Washers are divided into three major types according to their construction and applications.
|Main Types Of Washers||Sub-types|
|Plain Washers||● Torque washer
● Flat washer
● Fender washer
● Countersunk washer
● Shoulder washer
|Spring Washers||● Conical washer
● Dome spring washer
● Wave spring washer
● Finger spring washer
● Crescent spring washer
|Lock Washers||● Split lock washer
● External tooth lock washer
● Internal tooth lock washer
Let’s move toward the first type of washer!
1. Plain Washers
Plain washers, also known as flat washers, are the most commonly used. They are specified for spreading the load to a large area without affecting the assembled surface. The following are different types of plain washers:
a) Torque Washer
The torque washer features sharp prongs that penetrate the mating surface in order to avoid rotation. They are highly applicable in woodworking as they can be used in conjunction with bolts.
b) Flat Washer
Flat washers are the most widely used washers that are flat on both sides. They are circular, and a hole in the center allows you to secure the bolts. Moreover, these washers come in different sizes and thicknesses.
You can utilize a flat washer for general purposes. It is mainly used to distribute the load and protect the mating surface. Yet, they offer better support to small head screws than others.
c) Fender Washer
Fender washers are also plain ones with a larger outer diameter. Whereas the inner diameter is comparatively much smaller. Due to this reason, fender washers distribute force to a larger area than flat washers.
You can find the applications of fender washers in plumbing, sheet metal, electronics, automobiles, panels, drywall, and so on.
d) Countersunk Washer
The countersunk washers are designed for countersunk screws. Mainly, they have a countersunk (90° or 120°) on the top in order to provide a flush surface for screws. Sometimes, these washers are also known as finishing washers.
e) Shoulder Washer
As the name implies, the shoulder washer has a structure similar to the shoulder. Typically, these washers are manufactured from materials like nylon, PTFE, PCTFE, fiberglass, and metals.
Further, shoulder washers act as insulators; therefore, you can utilize them to insulate wires, screws, or other relevant parts. You can also use them to protect the fasteners from dirt and moisture.
The shape of the C-washer is similar to the alphabet C as it is open from the side. That’s why you can easily adjust it by sliding in and out of a bolt without removing the fastener.
2. Spring Washers
Spring washers are ring-shaped washers made of spring steel. They serve in case of shock or vibrations by offering an axial load to fasteners. Hence, it keeps the nut and bolt tightened in the equipment, which produces vibrations while operating.
Primarily, you can find spring washers in flight control and landing gear for their high degree of flexibility. Here are some types of spring washers:
a) Conical Spring Washer
Conical or Belleville spring washers are suitable to deal with thermal expansion and contraction situations by keeping the assembly in tension. They can withstand heavy loads with small deflections. The deflection capacity typically depends upon the height-to-thickness ratio.
Belleville washers are found in higher-friction applications to absorb shocks and thermal expansion.
b) Crescent Spring Washer
A crescent spring washer is slightly curved and mostly preferred to hold lighter loads. Yet, it offers a wide range of deflection. That’s why these washers are suitable for applications that demand high endurance and flexibility.
c) Dome Spring Washer
Dome spring washers also have a half-moon-like shape, but these possess ground curves that offer a flatter load-bearing surface. Dome washers have the ability to hold high loads but have a relatively short deflection range.
d) Wave Spring Washer
Wave spring washers are curved in two directions to serve as cushions or spacers. They can bear moderate loads and deflections. Plus, these washers prevent the surface from excessive wear and tear.
e) Finger Spring Washer
The finger spring washer consists of three flanges that are slightly curved. Normally, they are constructed using carbon steel. The combined properties of both crescent and wave washers provide high flexibility and load capacity in finger spring washers.
These washers are best for dampening the noise and vibrations. Plus, it also reduces the probability of skidding wear.
3. Lock Washers
Lock washers help prevent the fasteners from losing their grip and keep them intact in case of strong vibrations. The following are the types of lock washers:
a) Split Lock Washer
A split lock washer, also known as the helical washer, is not connected from an end, so each bent end of that point touches the mating surface. Typically, when it is fastened, the coil bites into the surface to offer a tight grip. However, using a split lock washer with a flat washer is good.
b) External Tooth Lock Washer
The external tooth lock washer consists of several teeth aligned on the outer diameter of the washer. The inner diameter of the washer is cylindrical. These washers are ideal for wide-headed fastener applications. The teeth play a vital role in resisting compression by making a solid grip on the surface.
c) Internal Tooth Lock Washer
The internal tooth lock washer is totally opposite to the external tooth lock washer. In the internal tooth washer, the teeth are aligned on the inner diameter length, while the outer diameter is cylindrical. These washers perform best when used with shallow-headed fasteners. When the teeth come in contact with the mating surface, they absorb the shock and vibrations.
Materials of the Washers
Washers are made of different materials to serve different roles in the construction and manufacturing industries. Most Commonly, washers exist in metal, rubber, and plastic materials.
1. Metal Washers
Metal washers are highly preferable for high-strength applications. Primarily, washers are made of galvanized carbon steel and stainless steel. Carbon steel possesses high strength, whereas stainless steel is famous for its corrosion resistance.
Furthermore, you can also find soft metal washers in the market, including copper. Below are some metal materials and their applications as washers:
- Brass washers are ideal for hot water applications.
- Silicon bronze washers are best for saltwater applications as they are highly non-corrosive.
- Yellow zinc washers are quite hardened so that they can be used outside. However, it may experience rusting slowly.
2. Rubber Washers
Rubber washers comprise nitrile, which is a synthetic rubber. Nitrile and nylon are almost the same things because of their similar properties. Yet, rubber is softer and flexible; thus, it is perfect for tight sealings. On the other hand, rubber washers can distort easily if they experience high compression force.
3. Plastic Washers
Your second preference after metal washers should be Plastic washers, especially if you don’t require high strength or want a cost-effective solution. Generally, they are considered suitable for electronic applications, as they offer electrical isolation and vibration resistance. You can get both colored as well as transparent plastic washers. Plastic washers usually consist of HDPE, PVC, nylon, or LDPE materials.
Finally, you come up with enough knowledge about the types of washers and their uses. As washers possess diverse specifications, you may choose a specific one according to the need of your application. However, the overall role of the washers is to prevent surface damage by distributing a load of fasteners while the machine operates at high pressure.