The Plumber's Choice 1-1/4 in. Hinged Split Ring Pipe Hanger, Malleable Iron Clamp with 3/8 in. Rod Fitting, for Suspending Tubing (5-Pack) 114HSHB-5 - The Home Depot
1 inch Cross Pipe Clamp Tube Holder Durable Marine Hardware Accessories Pipe Clip Fastener Metal Clamp for Marine Yacht Boat Fitting - Walmart.com
Pipe Alignment Clamps for external alignment of pipe & tubes & fittings.
The Plumber's Choice 1-1/2 in. Hinged Split Ring Pipe Hanger, Galvanized Iron Clamp with 3/8 in. Rod Fitting, for Suspending Tubing (5-Pack) 112HSHG-5 - The Home Depot
B&B Pipe 1222 PDQ Pipe Clamp (Large) fits 6 inches to 14 inches Pipe for Pipe Fitting, Fit Up, and Welding - Amazon.com
B&B Pipe 1220 PDQ Pipe Clamp (Small) fits 1" to 3" Pipe for Pipe Fitting, Fit Up, and Welding (One Pack) - Amazon.com
Tube clamps - Malleable Iron Pipe Clamp Fitting 143-A27.