Proline Series 1/2-in x 1/2-in Threaded Male Adapter Nipple Fitting in the Brass Fittings department at Lowes.com
1/2" Female NPT Brass Pipe Thru-Bulkhead
Solid Brass Pipe Mount Fixing Bracket Steam Punk Industrial Copper 1/2 15mm 3/4 22mm - Etsy
Brassfinders: Polished Brass Round Tubing (1/2 Inch OD)
Sioux Chief® 1/2" FIP Brass Tee at Menards®
1/8 IP x 3/16", Both Ends Threaded, Fixture Stem - Lamp Pipe, Your Choice of Lengths from 1-1/2" to 36" (1/8 IP = 3/8" diameter) (22249BU) - Antique Lamp Supply - Quality Lamp Parts Since 1952