A tensioning mechanism for a band saw includes a tension spring assembly coupled with a sliding tension bracket which is adjustably coupled with an upper arm of the band saw. The sliding tension bracket engages an upper band wheel which couples with a band saw blade. A cam assembly is coupled with the tension spring assembly, the cam assembly imparts a rotational force which is translated into a linear tensioning force by the tension spring assembly upon the band saw blade. A cover assembly is selectively engaged with the cam assembly through use of a biasing assembly. The cover assembly includes an index indicator for identifying an index position and includes a handle which enables a user to selectively engage and rotate the cover assembly. The rotation of the handle in turn rotates the cam assembly applying the rotational force which is translated into the tensioning force.