Both the box and the bag product name, seal with the left thread. But the contents are right hand screw. With the quick response of Mr. Monotaro, the left screw was sent as soon as possible. The product is satisfactory. However, with 10 mm left and right screws, there is no supply of nut. Other size screw nuts with no flanged or box type nuts If you can expand this side, I think there is even more use. Because there is no nut, scrape the screw to 100 mm taper and vertically slit 4, quench to make a tap, and made a nut with BC 6 gun metal.