What is the difference between Arch and Lintel?

As far as what they do there is no difference, and both support weight loading above them. Shape wise a lintel is usually flat compared to the curved shape of an arch. Strength wise the arch is far superior and only compresses more the greater the loading, compared with a lintel that has limitations to what it will hold before failing due to compression.

Having said that most lintels carry very little weight anyway as it is spread out through the interlocking of stone, block, or brick and the only weight it actually carries can be measured by drawing a line at 45° from each end of the lintel until they cross in the centre above it and what its actual loading is. Beyond that, the wall supports its own weight and that above it providing something supports the interlocking material and how the Victorians managed to support mass weight purely on timber lintels only 3 inches thick. With lintels, span becomes an issue very quickly much less so with an arch

Difference between ARCH and LINTEL :

Basically, the function of Arch and lintel is nearly the same, but obviously, there are some differences in between them. Here, I will be discussing some major differences, they are as follows;

1. In various major masonry construction, the arches have several great advantages over lintel because of its shape
2. The lintel has a horizontal beam, whereas the arch has a curved top and both are resting on two supports.
3. An Arch can carry a higher amount of load as compared to lintel
4. Because of the higher loading capacity of the arch, the pressure downward on an arch has the effect of forcing the voussoirs together instead of apart
5. The more rigid surface is required for lintel but arches may rest on light support.
6. A special type of centring devices is required for the construction of Arch.
7. Construction of lintel is very simple as compared to the arch.
8. In case of Arch, because of the special shape of blocks, the blocks support each other by the mutual pressure of their own weight and the structure remains in position by resistance from the support.

Lintels are mainly provided in openings like doors and windows.They are structural horizontal members.And they can bear load of masonry above the opening.So they are used for load bearing purpose above opening.They can also used for decorative purpose also.

Arch is also have same functions of a lintel.They are also provided to bear load above them.It is curved in shape.They are usually provided in bridges rather than buildings as they can span a large area.

The main difference between lintel and arch is, Lintel is a horizontal concrete member which are provided generally above the opening like a door, window, etc.

Arch is an inverted U shape member that is providing for architect purpose and generally arch generates unadulterated pressure so it is hard or not preferable by structural engineers.