I know professional CAD and 3D Graphic programs such as Solidworks, ProE, AutoCAD, 3D Studio Max, etc. can open and work with these.
What files do programs such as Google Sketchup, G-MAX, Blender, ect. import & export?
Craig did sent me a DXF file of his square nuts, but haven't had the time to try and open the files. I'll admit that in my 3D renderings I mostly use modern nuts and bolts, which have undersized heads when compared to fasteners of the 1870 - 1920 time period. The same goes for pipe fittings, I use models of the modern stuff.
Aaaaand one of the reasons I use modern nuts, bolts and pipe fittings is because they can be downloaded for free from McMaster Carr.
Another good free resource for modern pieces-parts is 3D Content Central.
Here are some standard parts I've modeled in 3D from real parts:
- Carter #3 Link & Pin Coupler
Draft Gear Cheek Block Castings
Carter #11 Stake Pocket
10ton / 15 ton Car Center Bearing
Box Car Truss Rod Washer Casting
Box Car Door Rail Support Castings - Carter / SPNG
Box Car Door Handle
Carter Truss Rod Bearing (King / Queen Post)
- 8ton Truck Center Bearing
10ton / 15ton Truck Center Bearing
10ton / 15ton Swing Motion Bolster Bearings
8ton / 10ton Journal Box Cover
15ton Journal Box Cover
15ton Swing Motion Bolster Straps
Brake Hanger Castings
24" Brake Head
24" Brake Shoe
A. Whitney & Sons 24" Wheel
- 3/4" Ogee Washer
1" Ogee Washer