This hook is intended to be pretty strong, for holding stuff like a heavy 10 AWG generator extension cord or heavy hose.

However, if you want it to be strong enough for a heavy 10 AWG generator cord, you'll probably want to beef up the settings from the “lightweighted” .3mf file.  That lightweighted file is the lightest I'd recommend printing this hook - it's beefed up only around the screw holes, and may break if used to hold anything heavy.

This hook uses a lot of filament when printed with more perimeters and infill, but is also pretty strong.

I recommend printing in PETG, with a brim.  PLA might work but I haven't tried it - it's possible that PLA might gradually deform under load; I hear PETG doesn't do that.  Without a brim, some lifting at the corners is pretty likely since this thing takes up the whole bed and the corners are out near the edge of the bed where it's not as hot, and the model prints tall enough to get some warping happening.  A brim seems pretty effective at preventing problematic lifting - maybe just a bit of lifting at the one sharp 45 degree corner.

To get the brim off, a deburring tool works pretty well, but it's a little tricky where the overhang angle is 45 degrees.

Because of the 45 degree overhang angle, I recommend 0.2 mm instead of 0.3mm.  To some degree the longer print time can be mitigated by using rectilinear infill with a line width of 0.85 when printing at 0.2 mm layer height.  I've not had much luck using rectilinear infill at 0.3 mm layer height (not unique to this print).

You'll likely want/need a bit extension (or a pretty small power screwdriver, or a long normal screwdriver) to screw in the bottom screw, since the model doesn't leave much extra room for that one.

The cost of printing a beefy version of this is likely to be higher than just buying a strong hook that's similarly rounded at the edges to avoid pinching a hose or cord insulation.  This also takes a long time to print.  But this way, you can make it with racing stripes if you want.

The .f3d is included in case anyone wants to remix to add additional screw holes or make the end of the hook taller or whatever else.  Please consider using the .f3d for any remixes to keep the .f3d continuity going, and to make any further remixes more plausible/sustainable.  To get the 45 degree overhang angle to work exactly the way I wanted, there's a parallel sweep cut involved instead of a chamfer or fillet in one place - a bit odd, but it worked.  This did lead to chamfers that come to a point instead of a triangle - I think it looks neat this way, but it'd be pretty easy to chop off the corners one more time in F3D to make them look like default chamfers if you like that better.