There is an error in the Solidworks toolbox - likely more, but I have recently noticed this one.... when inserting an imperial sized o-ring take note that the series o-rings that run from size 005 to size 050 are actually 0.070" in cross sectional diameter.  The Toolbox parts come in as 0.060" diameter, which is incorrect.  It is simple to change if you open up the part and edit the sketch, but you have to remove the write protect on the part before you can save it back to the toolbox.  If you do this, the next solidworks install will overwrite all your changes...... thanks Solidworks... nice job.

You may be best to save the revised part to a separate place to prevent having it overwritten at the next install.

Another blatant error with toolbox parts is that all metric threaded fasteners are shown with a thread angle of 55 degrees.  This is WRONG.  Metric threads are 60 degrees, the same as imperial threads.  The only threads that use the 55 degree angle are British Whitworth, which isn't used much any more apart from making repair parts etc as Britain changed to imperial threads etc about 30 years ago.

There is also an old British B.A. thread form (from about 1940) that has a thread angle of 47.5 degrees, but i havent come across that one.  The only other weird angle is the Lowenherz which is 53.8 degrees, but I have never seen that in use, but it certainly will show up in some areas of Europe no doubt.

In addition to the various thread angles, some thread have differing profiles having rounded points instead of a sharp 'V' for a flattened tip as is common in North America.

It is obvious the solidworks programmers didn't do their homework on this one either.....  there are Soooooooo many areas of the toolbox that are lacking features and fasteners, it would be nice if Solidworks would spend some of our money upgrading and adding new features and fasteners every update.