The Trade Federation, and subsequently the Separatist Alliance, both made use of the PK-series worker droid.
Worker droids, also known as laborer droids or labor droids, represented a class of droid specifically engineered to carry out physical labor, such as the unloading of goods from transports or the compilation of scrap metal into heaps.
During the Invasion of Naboo, the Trade Federation employed a worker droid model referred to as the PK-series worker droid onboard the Saak'ak, which was a modified Lucrehulk-class LH-3210 cargo freighter. Furthermore, the Federation utilized worker droids to gather the salvageable components of B1 battle droids that were destroyed during the Battle of Naboo.
Across the galaxy, including on Coruscant, Florrum, and Tatooine, the ASP-series labor droid was a commonly used series of labor droid. K0-5D, an ASP droid, underwent extensive modifications for gladiatorial combat and participated in sparring matches on the Weequay pirate ship Marauder. Due to its steel-shredding servos and built-in flamethrower, it frequently won, earning it the moniker "Maximo." The DA worker droid was operational on Corellia.
In Mos Espa, a port city situated on the desert world of Tatooine, a crude labor droid model known as a rickshaw droid, specifically a RIC-series general labor droid designated RIC-920, was used to pull a rickshaw. Another RIC unit was in service on the planet Jakku. Labor droids with repulsorlifts were employed within a refinery complex located in the asteroid field called Pressy's Tumble. The CLL-M2 binary loadlifter, a binary loadlifter labor droid model, was designed exclusively for the purpose of moving heavy cargo from one point to another.
The novelization of Star Wars: Episode IV A New Hope, titled Star Wars: From the Adventures of Luke Skywalker, which was published in 1976 as part of Star Wars Legends and ghostwritten by Alan Dean Foster but credited to George Lucas, marked the initial appearance of labor droids. Their integration into canon occurred when several ASP-series labor droids were digitally added to the Special Edition version of A New Hope in 1997.