Amazon.com: Structural Pipe Fitting, 1-1/2" Heavy Duty Square Base Flange, 34F-8, Aluminum Magnesium, Please note. ID of fitting is 1.925, to take nominal 1-1/2" steel pipe which all have an OD of
Amazon.com: 6 Sets Square T Fitting 1 Inch Tube Clamp Connector, 201 Stainless Steel 4 Way Square Tube Clamps Joint Chain Link Fence Clamp for 25mm Square Steel Tube, Thickness 1.8mm(Bolts/Nuts Included) :