Project aim is contribute in torsional vibration th eory and their practical experiences used in damper s which are widely used in automobile application & civil applications. Projec t is sponsored by �Hodek vibration Technologies pvt ltd�,pune. This is largest dampers manufacturer of torsional vibration dampers for diesel engines. This report paper high lights a number of important considerations for the torsional viscous damper system as well as design philosophies to ass ess and mitigate the risk of torsional failures. Damping properties are of si gnificant importance in determining the dynamic res ponse of structures,and accurate prediction of them at the design stage,es pecially in the case of light-weight,wind-sensitiv e buildings,is very desirable. Unfortunately,damping parameters cannot be deduced deterministically from other structural properties and recourse is generally made to data from experiments conducted o n completed structures of similar characteristics. Such data is scarce but valuable,both for direct use in design and for fur thering research into the phenomenon of damping. https://www.ijiert.org/paper-details?paper_id=140260