Reduce assembly time and labor cost with our Patent pending Steel Couplers. Use in your factory or Sell retail in your Metal Supply Store! We offer couplers such as: straight unions, 90 degree, 3 way flat, 3 way corner, 4 ways for 1 1/2" 14 ga and 16 ga sqaure steel tubes. Our couplers are made with a patent pending groove that allow them to easily slide into square steel tubes with welding seams for a snug fit. You can fasten them with a screw or a weld. Great for manufacturers and hobbyist. Also very popular for DIY projects like outdoor kitchen frames and trailers. Made of uncoated 18 gauge steel. Excellent prices under $10 bucks. Excellent product to sell retail in your Metal Supply Store!