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Up for sale is a well-preserved vintage 1973 Nelson NS-20 Stud Welder control box unit. This listing includes the main control box enclosure, front faceplate control panel, complete internal electrical components, and the attached heavy-duty trailing cable/plug assembly as pictured. **Please note** This is the control unit only. There is no welding gun, ground clamp, or separate power source included in this sale. This item is an exceptional piece of original American industrial manufacturing. The front faceplate still proudly displays its original white-and-green factory quality control inspector sticker reading "ACCEPTED BY 37 DATE 3 2 73", definitively dating this exact machine to March 2, 1973. The outer shroud has been removed for photography to give prospective buyers complete visibility into the pristine internal condition. It features a stamped aluminum internal specification plate verifying the official factory numbers (Part No. 701-011-001 / Serial No. 2016). All internal electronic components are high-grade, period-correct American parts, including a clean Ohmite brand sealed dustproof rheostat and a Littelfuse component setup.
• Item: Vintage 1973 Nelson NS-20 Stud Welder Control Box | (Unit Only)
• Manufacturer: Nelson Stud Welding Co. (Lorain, Ohio, U.S.A.)
• Model: NS-20
• Part Number: 701-011-001
• Serial Number: 2016
• Production Date: March 2, 1973 (Factory Quality Control Documented)
• Condition Note: This unit is being sold *AS-IS* | *FOR PARTS OR REPAIR* | *UNTESTED* | It has not been powered on or tested under load. However, the interior is exceptionally clean, dry, and well-preserved for a 1970s industrial tool. There are absolutely no signs of common vintage issues like burnt wiring tracks, or heavy oxidation. The exterior red metal casing shows typical cosmetic wear; scuffs, rust spots and dust consistent with its age, but remains completely solid with its top-mounted carrying handle intact. Please review all high-resolution photos carefully to assess the precise physical and electrical state.
• Key Technical & Component Details: Factory IDs: Stamped ID Plate with Part No. 701-011-001 and Serial No. 2016.
• Dated Verification: Original faceplate inspector sticker explicitly dated March 2, 1973.
• Premium Controls: Original Ohmite Sealed Dustproof Rheostat (1200 OHMS, SPEC 52427, Skokie, Ill.) attached to the timing adjustment dial.
• Fusing & Safety: Integrated original Littelfuse component block assembly.
• Contactor Assembly: Robust, heavy-duty vintage mechanical welding contactor/solenoid system inside the main chassis.
• Front Controls: Clean, highly legible front faceplate featuring a polarity switch dial (Reverse/Straight), time control dial, and a helpful approximate time control settings chart mapping stud diameters (3/16" to 1/2") to cycles (9 to 35).
• Ideal For: Sourcing clean, highly traceable, original replacement parts for an active Nelson NS-20 setup. An authentic, period-correct restoration project of a classic 1970s Nelson welding system. Industrial collectors or vintage tool enthusiasts looking for highly documented, original 20th-century workshop gear.
