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What rethreader sizes are available?

Shop for Rethreaders

pile of screws To understand how rethreaders are sized, it is important to understand screw sizes.
thread size equation m# x # All threaded items will be given a measurement like this:

M# x # (for example, M3.5 x 0.6). This is the metric screw thread scale.

thread equation dissected (metric, diameter, pitch) The M in the equation stands for metric. The first number is the diameter of the screw and the second is the thread pitch. The measurements are all in millimetres (mm).
thread pitch and diameter explained Diameter is the measurement across the width of the screw. Pitch is the measurement of one whole thread (as pictured).
thread size on rethreader All rethreaders should come with an M measurement (usually written on the handle). This is the measurement of the tool and the size of the hole it can rethread.
socket box can be rethreaded Rethreaders are primarily used on electrical housing equipment, like conduit boxes and socket switches, so the most common size is M3.5 accordingly.
small and large diameter rethreaders Rethreaders are available in many different diameters and can be used for various applications. Some of the larger rethreaders are useful to mechanics, while some of the smallest can be used on household items.

Rethreader length

rethreader lengths, extra reach There is not a set length for a rethreader; it is usually a small tool, no longer than 10cm (31516“), however there are extra reach versions available.