Petersen Mfg. of DeWitt, NE was the originator of the Vise-Grip. American Tool Co. was formed by a member of the Petersen family and was a corporate umbrella for several formerly family owned tool companies including IRWIN, which had been best known as a maker of bits. When Newell Rubbermaid bought American Tool Co., they kept the Vise-Grip brand but discarded Petersen Mfg. Some corporate type thought IRWIN was a better known name and eventually put that together with the Vise-Grip brand. But the quality of the tools appears not to have been a concern.