Types of Bolts


Types of Bolts:

There are various types of Bolts Explained below:
1. Hexagonal-headed bolt
2. Square-headed bolt
3. Cylindrical or cheese-headed bolt
4. Cup-headed or round-headed bolt
5. T-headed bolt
6. Countersunk-headed bolt
7. Stove bolt
8. Carriage bolt
9. Hook Bolt
10. Expansion bolt
11. Foundation or rag bolt
12. Eye-bolt
13. Stud Bolt

1.     Hexagonal-headed bolt:

 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. 


2.     Square-Headed Bolt:

 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. 


3.     Cylindrical or Cheese-Headed Bolt:

 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.

4.     Cup-Headed or round-headed bolt:

 Cup or Round-Headed Bolt

 

This bolt is used when projecting are undesirable and where better appearance is required. It is usually provided with a sung forged on the shank just below the head to prevent rotation of the bolt. This bolt is used in the construction of tanks and certain parts of locomotives.

5.     T-Headed Bolt:

 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.


6.     Countersunk-Headed Bolt:

 Countersunk-Headed Bolt

This form 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.

7.     Stove Bolt:

 Stove Bolt

A stove bolt has a round flat head which is bevelled on the underside to fit a countersunk hole, it is provided with a slot on the head. For screwing the bolt into a nut by means of a screwdriver. This is used for assemblies where precision is of no great importance, and it is desirable to have the head of the bolt flush with the surface of the work.


8.     Carriage Bolt:

 Carriage Bolt

This is used for fastening wooden parts together or for fastening metal parts to wood. It has squared portion directly under the head to prevent rotating when the nut is tightened or slackened.  

9.     Hook Bolt:

 Hook Bolt

The hook bolt is used in semi-permanent fastening in concrete. This is also used in cases where there is no room for a bolt hole through one of the pieces to be connected, or in cases where a bolt hole would seriously weaken a piece. So the hook bolt is used for attaching shaft hangers to the flanges of joists and girders.

10.   Expansion Bolt:

 Expansion Bolt

This type of bolt is used in attaching parts to brick, stone or concrete walls and floors. The bolt has an internally threaded split sleeve which is slipped into a hole made in the wall and then expanded by running in the screw. 

11.  Foundation or Rag Bolt:


 Foundation Or Rag Bolt

The foundation bolt is used for fixing into the stone concrete foundation, the head is wider at the bottom than at the top, and is led into a tapered hole. The tapered head is cut in an uneven manner (jagged) and molted lead or sulfur is poured into the taper hole to fill the space between the lead and the stone or the concrete as the case may be. Where great strength is required, four parallel bars or keys are used in addition.

12.  Eye-Bolt:

 Eye-Bolt

The eye-bolt is very commonly used for lifting purpose. It is screwed or turned inside a threaded hole on the top of the machine. Electric motors and medium and lightweight machinery are equipped with one or more eye-bolt so that they may be readily lifted and moved by an overhead crane.



13.  Stud Bolt:

 Stud Bolt

A stud bolt is consist of a plain piece of cylindrical steel which is screwed at both ends. It has no head like a bolt. The nut-end is threaded for a length slightly more than the thickness of a nut or nuts to be used. The other end called the metal end. It is threaded for a length at least equal to the diameter of the stud.   Stud is commonly used to cylinder covers engine cylinders.



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