Smith & Wesson K frame strain screw, blue $15.00 Part 55 on the exploded diagram. Used, excellent condition blue strain screw from a 19-4, K frame revolver. Will fit other models of K frame revolvers. Out of stock Category: Smith & Wesson Related products S&W 59/459/5904 series XP magazine springs 3 pak $34.97 Smith & Wesson K frame .38/.357 Extractor, recessed chambers $25.00