These Graphtec type or compatible blades come with a spring for each blade. PLEASE NOTE: These blades are for CE5000 series and larger cutters only. They will not work in the Graphtec Craft Robo.
Rationale for blades of different angles: The primary rationale for blades of different angles is cutting depth. A lower angle (45 degree) is great for thin materials, while a steeper angle (60 degrees) has a more vertical cutting orientation that penetrates deeper.