Replacing all of the OEM DISA valves screws costs approximately $45 which is expensive for screws. Here is an affordable aftermarket alternative!

8mm Hex Heads (contrary to torx on OEM)  

Stainless Steel

Includes all the screws needed to install DISA valves on your N52/N51 3 stage manifold. Thread count is greater than OEM screws so installation may feel tighter. Downward pressure may be necessary to start the threads. Tighten gently until snug, do not torque

Disclaimer: results may vary depending on the condition of your existing threads on manifold / small DISA.