Type of Bolts

Dear Readers,

Some of the most commonly used bolts are illustrated below: This would be very useful for all construction engineers.

Hexagonal-headed bolt

This is the most common form of a bolt and is used for general fasting purposes. The hexagonal head is chamfered at its upper end. 

To prevent rotation of the bolt while screwing the nut on or off, the bolt-head is held by another spanner. A hexagonal-headed bolt illustrated in the figure. It is used for Construction and machinery applications.

Square-Headed Bolt

This bolt is commonly used when the head is to be accommodated in a recess. This recess is made of square shape so that the bolt is prevented from turning when the nut is screwed on or off.

When a square-headed bolt is to be used with its head projection outside, it is provided with a neck of square cross-section. This prevents rotation of the bolt. This bolt is commonly used in bearings for the shaft. A square-headed bolt is shown in the figure. 

Cylindrical or Cheese-Headed Bolt

This type of bolt is used where projecting corners are unacceptable, and where the space for arranging the bolt-head is relatively limited. The rotation of the bolt is prevented by means of a pin inserted into the shank just below the head.

The projecting part of this pin fits into a corresponding groove in the adjacent piece. This bolt is commonly used in big ends of connectors, eccentrics, etc.

Cup-Headed or Round-Headed Bolt

This bolt is used when projecting is undesirable and where better appearance is required.

It is usually provided with a sung forged on the shank just below the head, as shown in the figure. To prevent rotation of the bolt. This bolt is it used in the construction of tanks, certain parts of locomotives and Wooden works.

T-Headed Bolt

This type of bolt is used for securing clamps, vices, and other accessories to the tables of machine tools.

The tables are provided with T-slots to accommodate the T-heads. The neck of this bolt is usually square in section to prevent rotation of the bolt. T-bolt is shown in the figure.

Countersunk-Headed Bolt

This form of a bolt is used where the head of the bolt must not project above the surface of the connection piece.

It may be provided with a snack or a neck to prevent rotation of the bolt.

For More Information about Grade of Bolt Click Here

For More Information about Weight of Hex Bolt & Nut Here

Difference between Pipe and Tube

Dear Readers,

From a layman’s viewpoint, Both Pipe and Tube seem to be the same as they have many similarities like both are hollow, made from metals, both can transfer fluids, etc. However, there are significant differences between pipe and tube.

The difference between pipe and tube is marginal. They differ in the way they are sized. The pipe is generally specified by the internal diameter (ID) whereas tube is specified by the outside diameter (OD), but its dimensions may be given as a combination of ID, OD and the wall thickness.

What is Pipe?

Pipe is a hollow section with round cross section. Always cylindrical or round in shape for the conveyance of products. The products include fluids, gas, pellets, powders and more.

What is Tube?

Tube in general, cylindrical. However, refers to round, square, rectangular and oval hollow sections that are used for pressure equipment, for mechanical applications, and for instrumentation systems.

Unit Weight of Hex Bolt and Nut

 A bolt contains two parts a shank and head. The cylindrical portion of the bolt is known as the shank. The shank is threaded at the tail end for a sufficient length so as to effectively engage with a nut.

The shape of the head is depended upon the purpose for which bolt is required. The nut is a type of a fastener which has a threaded hole in it. The nut is always used in joining with a mating bolt to fasten various parts together.

Bolts and nuts can be made of various materials such as steel, titanium or plastic. The finish or plating on a metal bolt or nut affects its look and durability. Below are some common finishes and benefits:

• Zinc - Most common, low cost, resists corrosion and rust

• Nickel - Very hard finish, higher investment, good corrosion resistance

• Chromium – Bright finish, good rust and corrosion resistance

• Chromate – Adds color, shine, superior rust resistance

• Anodizing - Aluminum, hard oxide surface, excellent corrosion resistance

Generally purchasing of fasteners are in Kilograms instead of pieces. But we could not know how many numbers available per Kg. For construction purpose, Bulk purchase is advisable. Hence below count table will be useable. Counts are based on 50Kg

For More Information about Grade of Bolts Click Here

For More Information about Torque Clique Here