Clamping device including sheet metal, wedge-washers, and fastening members. Sheet metal includes first segments and second segment, where each of the first and second segments include conduit-facing end and outwardly-extending end. Conduit-facing ends are joined to each other and wrapped around conduit in opposite directions. Outwardly-extending ends extend in opposite direction to outwardly-extending end. Each outwardly-extending end is bent at bend angle towards a respective conduit-facing end. Wedge-washers are disposed on first and second segments. Each wedge-washer includes sidewall inclined in a direction opposite to bend angle and in contact with a respective outwardly-extending end. Fastening members are disposed on respective wedge-washer.