Professionally made gymnastics bars can cost from hundreds to thousands of dollars from gymnastics equipment companies. Building a single bar by yourself may greatly reduce the cost. Gymnastics bars used in gyms are made of galvanized steel, but you can construct a practice bar out of wood materials for use in your home.
DIY Gymnastics bars. I dont remember the exact dimensions but made with pvc pipes & pvc cement, the bar is a metal bar from plumbing aisle, it screwed right into the pvc (then glued) the fabric is felt, it was a long process of tightening, trimming and glueing. I used a flexible super glue
How to Make Parallel bars out of pvc pipe. Use for kids gymnastics or adults can use them in their workout routine for dips etc... http://www.theleanberets.com/wp-content/uploads/2013/05/Bars-PVC-High.pdf