Right-Handed Threads

Right-handed threads are the most common thread direction used on fasteners. With a right-hand thread, you tighten the screw or bolt by turning it clockwise and loosen it by turning it counterclockwise. If you look at the fastener from the end, the thread “ramps” upward to the right as it moves away from you, which is why it’s called right-handed. Unless a fastener is specifically marked or specified otherwise, it is typically assumed to be right-hand threaded.

Right-handed threads are used in the vast majority of nuts, bolts, screws, and threaded inserts because they match standard tools, common user expectations, and most manufacturing and design conventions. Choosing the correct thread direction is important for assembly and safety: a right-hand nut will not engage properly on a left-hand bolt, even if the diameter and pitch match. In the rare cases where a left-hand thread is used to prevent loosening from rotation or vibration, it is usually clearly labeled with “LH” or otherwise called out on drawings to avoid mix-ups during installation.