we collected original hinges dating from the 1870's and faithfully reroduced them in cast iron.  They have removable pins.  Black powder coated to last for generations.  
We have a full range of sizes: 
2 x 2"
2.5 x 2"
2.5 x 2.5
3 x 3"
3 1\2 x 3 1\2
4 x 4"