Selecting the proper antenna mast pipe is crucial. Depending on the size of your antenna, it's EPA, weight and height all play a factor in selecting a supportive pole. When planning, it's best to have all the information you can get like outside diameter of your attaching method, the clearance of gutters, siding or other obstacles in the path of your erecting a mast or tower.
Here you will find standard straight pipe in 5' foot and 10' foot lengths. You can also find those same pipes with a special end called a swag. A swaged ended pipe allows you to attach several lengths of pipe together.
When selecting a pipe you will need to know the length, OD (outside diameter), the AWG 16 or 18 (the smaller the number the thicker the steel) and weather you'll need any swaged ended pieces. You'll then need to select the proper mounting such as wall, roof or maybe a tripod.