This is a replacement Thumbscrew for Main Vertical Shaft for the Sailrite® HandyPress. It fits into both the top and bottom threaded holes on the end of the main vertical shaft. The screw secures upper adapters and/or dies to the main vertical shaft when using the shaft's inner diameter. 

Note: This thumbscrew cannot be used when using the main vertical shaft's outer diameter for upper adapters and/or dies. A threaded hole on the right side of the machine top, near the base of the handle, acts as storage for the thumbscrew when using the shaft's outer diameter.