A drill rod is simply tool steel that is still in the unhardened state. While it is still quite tough, the steel is still soft enough that it can be machined and formed into the required design before being heated and hardened so it can work on the job. In most cases, you will find that the drill rods are going to be round. However, it is also possible to find those that are square in shape.
Drill Rod Manufacturers
Many companies today are making drill rods. Some of the manufacturers include Iljin Steel Corp., Bedford Steels, Willi Wader Systemtechnik GMBH, and Crossroads Global Trading Co., Ltd.