by They are one of the most commonly used fasteners in construction, engineering, and manufacturing industries. Their simple design makes them look humble but they play a crucial role in holding together large structures reliably. Different types are used for different applications based on the material to be joined and load/stress requirements.
Types Based on Material
Carbon Steel Bolts
They are the most widely used type due to their balanced strength and cost. They can withstand moderate loads and temperatures ranging from -50 to 300 degree Celsius. For applications requiring occasional disassembly, they are a good choice. Common examples include general machinery components and automobile engine assemblies.
Stainless Steel Bolts
They are highly corrosion resistant and maintain their strength even at elevated temperatures up to 900 degree Celsius. Bolts They are specified for applications near seaside, chemical plants etc. where corrosion can be an issue. They are also used in cookware, medical equipment, and food processing industries due to their non-reactive properties. However, they are more expensive than carbon steel .
Alloy Steel Bolts
They are made of alloy steels like chromium alloy and nickel alloy steels provide higher strength at elevated temperatures compared to carbon steel. They retain strength beyond 300 degree Celsius. They are extensively used in critical components of gas turbines, steam engines, and downhole oil equipment where loads as well as temperatures are severe.
Designs and Specifications
Hexagonal Head Bolts
Hexagonal heads, also called hex are the most common type found virtually everywhere from household shelving units to shipbuilding. The hexagonal shape provides secure driving and tightening with a wrench or socket. Standard hex are available in coarse and fine thread variants for corresponding nuts based on the application.
Button Head Bolts
They feature a spherical shape that allows for multidirectional movement after installation. They are preferred where need to move or pivot against each other parts. Common uses include hinges, latches and other hardware requiring free movement.
Cap Screws
Cap screws resemble externally but have internal threads for insertion into a threaded hole like a machine screw. They are self-locking and find applications like joining pulleys to shafts, securing gears and flywheels where vibration or shock loads are involved.
Structural Bolts
They used for joining steel beams and girders in buildings comply with specifications laid out by American Society for Testing and Materials (ASTM). Properties like minimum tensile strength, dimensions, tolerances, coatings are standardized. High strength friction grip (HSFG) provide pretension in steel connections through special washers.
Roof Bolts
They used for joining metal roof sheets and panels need to withstand extreme weathering. Hot dip galvanized coating on prevents rusting. Some roofing systems use sealant washers beneath its heads to prevent water ingress through joints. Proper torque is important for Weathertight fittings.
Wonder of Engineering Structures
Brooklyn Bridge – Icon of Industrial Revolution
One of the engineering marvels of the 19th century, the Brooklyn Bridge which connects Brooklyn and Manhattan across the East River, was constructed using nearly 18 million pounds of iron and steel hold together by over 1.5 million iron and steel ones.This suspension bridge which was the longest in the world when completed in 1883, is still standing strong witnessing over 1.5 million pedestrian daily owing to the tensile strength,
Golden Gate Bridge – Bold Colorful Span
Carrying over 100 million vehicles since opening in 1937, the spectacular Golden Gate Bridge in San Francisco is anchored by massive vertical mast structures housing the suspension cables that are tensioned using turnbuckles. At either ends, its clusters rooted into anchorages precisely sized in diameters transfer titanic magnitudes of forces locking the entire structure in place. The resilience allowed the bridge to endure strong earthquakes over the decades.
Eiffel Tower – Architectural Marvel
The elegant pylon like iconic structure that is the Eiffel Tower was principally riveted together using over 2 million rivets when constructed as the entrance arch for the 1889 World’s Fair in Paris. Although originally meant as a temporary exhibit, its skeletal frame stayed safe strengthened by secondary one added later on during necessary repair works. Today tourists throng this symbol of structural engineering design held by millions of fasteners including them.
*Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
