These new eccentric nuts are a revision of the standard eccentric nuts that have been a part of the Shapeoko 3 from the start.
These HD Eccentric Nuts feature the following：A larger bearing surface to reduce deflection as the nut is tensioned
Deeper threads
Longer neck to reach deeper into the steel axis plates
The HD Eccentric Nuts are sold as a 9 pack, enough to swap out all of the nuts on your Shapeoko 3 and still have an extra to lose somewhere on the ground in a corner.
Note：Starting January 2020 all Shapeoko CNC routers began shipping with HD Eccentric Nuts as the standard option. So, there is no need to upgrade if you purchased a machine in that time frame.
