For a recent blog article on Rack-Mounting Network Devices, I found myself in need of a simple shape to represent a bolt (as viewed from the side) for a technical illustration. Although Visio includes many stock screw and bolt shapes, these are intended for complex mechanical drawings and not easily manipulated. So, I set about creating my own from simple shapes.
First I created an overlapping oval and rectangle to represent the bolt head.
Obviously, as independent shapes they don't much resemble what we want. We can use shape operations, found under the developer toolbar, to combine the oval and square into a complex shape. Select both shapes and click Operations > Union on the developer toolbar. (If you don't see the developer tab on the ribbon in Visio, enable it under File > Options > Customize Ribbon.) Now we have the shape of our bolt head.
Next we'll add another rectangle to form the length of the bolt. Align the square horizontally with the middle of the bolt head. Then, select Operations > Combine to combine the shapes. Notice that the combine operation differs from union in that the border between the two shapes is maintained.
We now have a single shape that we can style and manipulate however we choose.
The best way to become comfortable with shape operations is simple trial and error. Note that for some operations, such as subtract, the order in which shapes are selected prior to performing the operation affects the end result.
Even with my severely limited artistic ability, I've managed to create some vaguely representative shapes. I encourage readers to experiment with the various operations and see what they can some up with.