B65-607 SCREW-ARM PLOW PLANE. E.W. Carpenter. In addition to his improved design patented in 1838, Emmanuel Carpenter also made standard screw arm plows, which have the same unique nut design but are actually less common than the improved design. This is a nice clean beech example, unhandled, with a couple of small chips to the threads and an Ohio Tool Co. cutter. From the collection of David Jeffers. Good+ 200-400