How metal tubes are made and measured for furniture
Most of our product line is made up of tubular steel. We bring it in a many different sizes. Steel comes from the foundry in large coils. Those coils get cut down so that they are the right size for the particular tube. We have tubes that we use that are 1 inch and we have tubes that are as thick as 3.5 inches. We will start with 1 inch tubing. 1 inch tubing means that the diameter of the tube is 1 inch. The next measurement we need to know is the thickness of the steel tube. Richardson Seating uses a range of 14 gauge to 19 gauge. Gauge is how the US typically measures the thickness of steel. The lower the number the thicker the steel. An easy way to think about this is a 12 gauge shotgun vs an 18 gauge. The 12 gauge is thicker and more powerful. In other countries they make tubing that is 25 mm which is very close to 1 inch. The thicker the steel on the coil, the thicker the tube is going to be. They may measure in gauge but they all measure in millimeters. After the tube is made, it needs to be cut so that it can be moved around. We can take tubing in that is 14 feet long or smaller. We need to get it in our elevator. After the tubing gets cut to size.
In order to become a bar stool part, the tube needs to be bent, and punched. It also needs to be powercoated or chrome plated.
Some tubes are thicker at one end and then thinner at another. That is called a swaged tube. Swaging is the act of pounding the tube repeatedly until it gets the tube gets smaller and thicker. We have some products that use this style of tubing. The one inch steel is swaged into 5/8 inch at the bottom.