The Rebco A Solid Bar Stem is a solid alloy steel bar that serves as the primary weight source in the wireline tool string. Its mass overcomes three competing forces that prevent the tool string from entering the well: wellhead pressure acting on the wireline's cross-sectional area, stuffing box packing friction, and wellbore fluid drag. The same weight that drives the string downhole is also the source of impact energy when jarring; the greater the stem weight above the jars, the higher the jarring impact force delivered to the downhole tool. As a general rule of thumb, a minimum of 5 feet of 1½" OD stem (approximately 29.2 lbs) is used for well pressures up to 1,000 psi, with approximately 2 additional feet added for each subsequent 1,000 psi. Available in standard lengths of 2 ft, 3 ft, and 5 ft, in standard threaded sucker rod connections from ⅜" to 2½" OD. Smaller ⅜" and ½" OD versions are available for velocity string completions. All Rebco stems are manufactured with machined flats for safer wrenching; never grip the fishing neck.