TWO 5% Cobalt Square Ground 5/16" x 5/16" x 2-1/2" Tool Bit Shanks Spain

Description

For sale is a lot of 2 Square Ground 5/16" x 5/16" x 2-1/2" Tool Bit Shanks made with 5% cobalt. I got these in a toolbox with other things and don't know much about them. The only markings are the dimensions, 5% cobalt, and Spain as the country of manufacture. I'm not exactly sure what type of steel or brand they are. There is some rust, as shown in the photos.
I ship very fast most times within hours after receiving payment Mon-Fri.