Square drive makes the screw less of an issue for stripping it out. Great for a project where security is an option.Self-Drilling Screw, #8 x 1 1/2 in, 410 Stainless Steel Pan Head Square Drive These are used for metal applications where self tapping screw is needed..
Caldwell Series 200 Aluma-Tilt Spiral Window Balance - 29" Blue Tip When taking measurements, measure only the metal tube.These measurements are crucial to the performance of the balance.