Bolt Vs Screw | What Is Bolt | What Is Screws

Bolt Vs Screw

What Is Bolt?


A bolt is an externally threaded fastener created for the insertion through holes in the assembled parts. Generally, bolts are intended to be released by nuts.

This Bolts in a uniform circular cross-section, the threads are spiral in structure and have a smaller pitch as compared to screws. These bolts don’t have tapered shanks, and the parts secured by bolts possess greater strength than parts secured by screws.

These bolts act on the application together with the nut and are tightened on the part in which the torque is applied. Some of the generally used bolts are plow bolts, carriage bolts, and track bolts. The reliability and durability of parts joined by bolts are much higher than those joined by screws.

Applications that use bolts include flange joints or fastening of objects made of metal materials. Moreover, bolts aren’t only used in machinery but also plumbing and electronics. Z Bolts are an integral part of equipment and component reliability.

Bolt Pretension

Bolt Preload – The tension created when the nut is screwed onto a bolt to hold two materials together.

When the tension reaches the optimal preload, the working load (load added after creating the assembly) placed on a bolt will be distributed into the installation materials, so the bolt does not take the entire load.

Also, read: What Is Spalling Concrete | Causes of Spalling in Concrete | Repairing Concrete Spalding 

What Is Screws?


A screw may be defined as an inclined plane wrapped around a nail and characterized by a helical ridge. In other words, it is a long metal shaft with threads circling along its length. It also has a turning where a screwdriver can be used to rotate the screw.

A screw generally has a head with a specially formed shape. The shape determines and heads size the size of the tool to be used to turn or drive the screw. Commonly used tools are wrenches and screwdrivers.

The underside part of the head is a shank that can be fully or partially threaded. A screw thread is a structure on a coned or cylindrical shape in the form of a helix.

The top of the ridge is known as a crest and the bottom root. The distance between the crest of the one thread to the next one is known as a pitch.

Screws are tightened by rotating the tool anticlockwise or clockwise and are usually used for joining materials that don’t have existing holes in them.

The most common types of screws used in manufacturing are drywall screws, dowel screws, mirror screws, and concrete screws. The strength of a screw relies on the width of the thread and the distance between them.

However, the more numbers of the threads, the more rotations would be required to attach the screw. Also, if the continuous distance thread is wider, more force must be exerted on the tool in the rotations.

Screws are widely used in many applications. From motorcycles to furniture, from air conditioners to kid’s remote control cars.

Also, read: Why Is Polymer Mortar/Concrete | Type of Polymer Mortar/Concrete

Bolt Vs Screw-2

Bolt Vs Screw

Difference between nolt and screw are as follows.

Sr.No. Bolt Screw
1 Screws are tightened by rotating the tool clockwise and are usually used for joining materials that do not have existing holes in them. A screw is an externally threaded fastener capable of being inserted into holes in assembled parts, of mating with a preformed internal thread or forming its own thread, and of being tightened or released by torquing the head.
2 Bolt is always used in pair like nut & Bolt Screws are always used by itself.
3 Bolts are used with un-threaded components. Screw can be used with threaded or un-threaded components.
4 In the bolt cross Uniform section In screw can have non- uniform cross section
5 The threads are spiral in shape. The threads are helical in shape.
6 It doesn’t have tapered shank. It has tapered or pointed shank.
7 This Bolts mostly require wrenches and spanners for the tightening and loosening purposes. This screw requires mostly screw drivers for the tightening and loosening purposes.
8 This bolt is reliable Here, Screw is less reliable
9 Bolts are larger in size. Screws are smaller than bolts.
10 Larger size bolts are used to achieve higher load-carrying capacity. Screws are not available in very large size. They are generally used for low load carrying applications.
11 Bolt are always fixed at a single position with the use of a tool. Screws has to be turned every time it has to be assembled.
12 They apply compression on the parts that they join. They don’t apply compression on the parts that they join.
13 They are often used in the making of bolted joints. They can’t be involved in the bolted joint making due to the presence of at least one thread.
14 The examples of bolts are Anchor bolt, T-head bolt, Toggle bolt, U-bolt, J-bolt, Eyebolts, Hexagon bolt/Tap bolt, Lag bolt, Machine bolt, Carriage bolt, Elevator bolt, Flange bolt, Hanger bolt, Plow bolt, Sex bolt, Shoulder bolt, Square head bolt, Stud bolt, Timber bolt, etc. The examples of screws are self-drilling, socket screw, eye lag, mating screw, Wood screw, machine screw, thread cutting machine screw, sheet metal screw, set screw, etc

Bolt vs Screw

So, the fundamental difference between screws and bolts is that the former is used to assemble threaded objects, while the latter is used to assemble untreaded objects. It’s also worth noting that screws must be turned to assemble a joint, while bolts can be secured in place using a tool or a carriage bolt.

Difference Between Screw and Bolt

A bolt is a non-tapered fastener that uses a washer and nut to hold objects together. A screw is a tapered fastener that mates with an existing thread or creates its own thread in a material as it turns.

Leave a Comment