A key sprocket drive system for a conveyor belt having a drive drum having an outer surface. The outer surface of the drive drum is adapted to engage a securement means. A contoured collar has an inner surface and an outer surface. The contoured collar is adapted to receive the securement means and adapted to engage the outer surface of the drive drum at predetermined positions therefore providing defined gaps between the inner surface of the contoured collar and the outer surface of the drive drum. The key sprocket drive system further comprises a sprocket member having a generally annular configuration with externally facing teeth-like protrusions at spaced intervals. The sprocket member is adapted to receive the securement means whereby the securement means engage the sprocket member and the contoured collar to secure the sprocket member and the contoured collar to the drive drum. The teeth-like protrusions engage the conveyor belt so as to drive the conveyor belt.