A trigger speed control switch for use on portable tools having double-pole contacts with wiping action, larger contact opening gaps, screw-clamp terminals for connection of the power line conductors, a printed circuit board for mounting the speed control circuit, an adjustable trigger lock mechanism with detenting to hold it in adjusted position, and terminals for connecting a load device such as a motor as well as an external filter capacitor. A small version having all of these features is small enough for direct substitution for an on-off trigger switch as well as for universal portable tool application. A larger version having all of these features is adapted for substitution for present wired-components types of trigger speed control switches. In either case, modification of a given tool is not required to receive the double-pole trigger speed control switch.