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.
