What are the three types of bolts?

2025/01/08 16:30

Bolts can be classified into several types based on different criteria. Here are three common classifications:

1. Based on the Head Shape

Hexagonal - Headed Bolts:

These are the most commonly used types of bolts. The top of the bolt is hex, so you can use a wrench to tighten or loosen it. Hex bolts come in many different grades and sizes, and have an extremely wide range of applications ranging from machinery assembly to construction. For instance, if you were constructing a wooden structure, you could use hex bolts to attach beams and columns.They provide a reliable and strong connection point.

Based on the Head Shape

Round - Headed Bolts:

Round - headed bolts have a circular head. They are often used in applications where a more finished or aesthetic look is desired. The rounded head can also help to distribute the load more evenly in some cases. For instance, in furniture making, round - headed bolts might be used to attach table legs to the tabletop, as they can provide a smoother appearance while still offering a secure connection.

Round - Headed Bolts

Flat - Headed Bolts:

They have a head that sit flush with the surface of the material being fastened Flat – headed bolts. In this context, they are well-suited for applications that require a smooth surface. These serve in cases where a protruding bolt head is undesired and would impede neighboring components. Automobile body panels are fastened with flat - headed bolts so they can have a smooth surface on the outside.

Flat - Headed Bolts

2. Based on the Thread Type

Coarse - Thread Bolts:

Coarse - thread bolts have threads with a relatively large pitch. This means that there are fewer threads per unit length compared to fine - thread bolts. They are easier and faster to screw into a nut or a tapped hole because the larger threads can engage more quickly. Coarse - thread bolts are generally more forgiving in terms of alignment during installation and are better able to handle materials that are less than perfectly machined. For example, in construction work, coarse - thread bolts are often used to fasten wooden components together as the wood may have some irregularities.

Fine - Thread Bolts:

Fine - thread bolts have a smaller pitch, resulting in more threads per unit length. They provide a more precise and tighter fit. Fine - thread bolts are better at withstanding vibration and are less likely to loosen over time. They are often used in applications where a high degree of precision is required or where the bolt is subject to significant vibration. In machinery and equipment where precision is crucial, such as in the assembly of high - speed engines, fine - thread bolts are commonly used to ensure the components stay in place.

Self - Tapping Bolts:

Self - tapping bolts can cut their own threads when driven into a material. They are used with material which does not have pre - threaded holes with materials like sheet metal. Self - tapping bolts have a sharp end with a cutting edge that creates threads as the bolt is threaded into the material. This makes installation easier, particularly in mass - production applications that make pre - threading hole preparation either time - or - labour - consuming or impractical. Self - tapping bolts are commonly used to assemble the panels in the manufacture of metal enclosures for electronics.

Based on the Thread Type

3. Based on the Material

Steel Bolts:

Steel bolts are the most common type. They can range from low - carbon steel to high - strength alloy steel. Low - carbon steel bolts are relatively inexpensive and are used in applications where high strength is not a critical factor. High - strength alloy steel bolts, such as those with chromium, molybdenum, or other alloying elements, are used in applications that require a high load - carrying capacity and resistance to wear and fatigue. For example, in heavy - duty machinery and automotive applications, high - strength steel bolts are used to ensure the safety and reliability of the equipment.

Steel Bolts

Stainless - Steel Bolts:

Stainless – steel bolts are Freustretch to corrosion. They are manufactured from an alloy of steel with a high chromium content that forms a passive oxide layer on the surface of the bolt, so there is no rust and no corrosion. Stainless - steel boltsApplications - stainless - steel bolts are used when the bolts may come in contact with moisture, chemicals, or other corrosive environments. For instance, stainless - steel bolts are required to avoid oxidation with salt - water for applications in marine engineering such as boat building and offshore equipment.

Brass Bolts:

Brass bolts are made from an alloy of copper and zinc. They have good corrosion - resistance, especially in environments where they are exposed to water and some chemicals. Brass bolts are also non - sparking, which makes them suitable for use in environments where there is a risk of explosion due to flammable gases or vapors. They are often used in applications such as in the plumbing industry for connecting pipes and fittin


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