where can I find a library of various bolt heads to insert into my drawing as a block ?
I am drawing a frame for a Hydraulic press tool bench and want to place a bolt head on my drawing to show where the frame will be secured
If you do a search from an internet search engine for something along the lines of "bolt head block" there are dozens of sites that come up:
There might even be some in the GrabCAD library, but I tend to use this site for 3D models.
When I design complex assemblies I try to design it around standard off the shelf fasteners. Almost all of the standard fasteners available at McMaster Carr have cad file available for download for free. https://www.mcmaster.com/
Hope this helps.