Round hole shim stock has precisely drilled holes, while slotted shim stock has slots that run the length of the sheet. Slotted shim stock is more versatile than round hole shim stock, as it can be cut and folded to fit various shapes and sizes.

Slotted shim stock is typically made from spring steel or stainless steel. Spring steel is more durable and can withstand higher loads, while stainless steel is corrosion-resistant and suitable for use in wet or corrosive environments.

The thickness of slotted shim stock you need will depend on the application. Thicker shim stock is more rigid and can withstand higher loads, while thinner shim stock is more flexible and can be used in tighter spaces.

Slotted shim stock is commonly used in a variety of applications, including leveling machinery, filling gaps, and adjusting tolerances. It is also used in the automotive, construction, and aerospace industries.