A setting tool for use in wells includes a mandrel formed with an interior combustion chamber. The setting tool further includes a barrel piston sized and configured to extend at least partially over an exterior of the mandrel and a shear device coupled to a portion of the mandrel and coupled to the barrel piston when in an in-line configuration. The mandrel includes an upper portion having a lead portion, an engagement portion, and a wrench-application portion. The wrench-application portion has a longitudinal length in the range of 1.5 to 3.0 to receive a wrench and avoid damage to the shear device. Other tools are disclosed.