Amazon.com: Structural Pipe Fitting, 1-1/4" Adjustable Ell or Tee, 80A-7, Aluminum Magnesium, Please note. ID of fitting is 1.68, to take nominal 1-1/4" steel pipe which all have an OD of 1.66". :
10 Sets 1 Inch 90 Degree Structural Pipe Connector 3 Way Metal Joint Chain Link Fence Clamp, Stainless Steel 201 Corner Fitting End Rails Clamps, Thickness 1.8mm - Amazon.com
SteelTek Structural Pipe Fittings for Tables Desk Bookshelves Furniture Building | eBay
Amazon.com: Structural Pipe Fitting, DIY Outdoor - 1-1/2" Adjustable Base Flange, 89A-8, Aluminum Magnesium, Note: ID of fitting is 1.925, to take nominal 1-1/2" steel pipe which all have an OD of