Abstract: A standard attachment temporarily converts a drywall screw gun into a drywall router-bit cutter. Adapters unique to particular brands of screw guns may be employed to allow the standard attachment to be mounted on guns of the different brands. The attachment effects a twenty-times speed-up of the screw gun screwdriver RPMs to achieve required router-bit RPMs, while depressing a special function of the screw gun. Snap rings and snug slidable fittings are utilized to effect quick attachment/detachment. A belt clip on the attachment facilitates maintaining the attachment readily accessible. In an alternate attachment form, an external portion of the housing is substituted to allow the attachment to be mounted on guns of different brands. Different types of the attachment forms allow mounting on guns which may or may not have their depth control mechanism adjustable sleeves readily removed.