These screws are perfect for embedding in metal clay and firing in place. Use them to make threads for rivet applications. The 256 size is the size being used in Rio Rewards certification project, the pen. The size 80 is much smaller, which is great for cold connections.
These great small stainless steel components can be used for cold connections. If you are ordering the Hex Head bolts you might want to consider the Hex Head Socket Wrench. Also, don't forget to get the Precision Screwdriver set!