Make tools, fittings, and small metal pieces used in other products.
Calibrates hydrometer tubes, using chemical solutions, marking device, and graduating machine: Mixes solutions of high, medium, and low specific gravity according to formula. Tests solutions, using standard hydrometer, and adjusts specific gravity of solutions. Places specified ballast weight into hydrometer float and seals hydrometer, using sealing compound. Immerses hydrometer into prepared solutions and marks levels of each solution on hydrometer tube. Graduates hydrometer, using engraving machine. Lines paper or metal scale into degrees, using drafter’s pen or metal scriber, and secures scale inside hydrometer to ensure lines correspond to graduations on hydrometer.