Gibraltar Z9805-25 Round Arbor Shim 18-8 Ss Pack of 25

Product Description

The GIBRALTAR Z9805-25 is a round arbor shim manufactured from 18-8 stainless steel. It is designed to fill small clearance gaps, adjust bearing fits, and maintain precise spacing in mechanical assemblies. The shim measures 0.005 inches thick with an inside diameter of 0.313 to 0.318 inches and an outside diameter of 0.495 to 0.505 inches. Thickness tolerance is held to plus or minus 0.0005 inches, making it suitable for applications that require consistent stack-up control. Each package contains 25 shims. Machinists, millwrights, and maintenance technicians working on rotating equipment, shaft assemblies, and precision fixtures are the primary installers.

This shim is used in industrial and commercial maintenance applications wherever tight dimensional tolerances are required between mating components. Typical uses include arbor and spindle assemblies, pump and motor shaft fits, conveyor and drive systems, and general mechanical alignment work. The 18-8 stainless steel construction provides corrosion resistance suitable for wet, humid, or mild chemical environments. The small OD and ID dimensions make this shim appropriate for light-duty precision work rather than heavy structural loading.

Key Features

• 18-8 stainless steel construction for corrosion resistance in demanding environments
• Precision thickness of 0.005 inches with tolerance held to plus or minus 0.0005 inches
• Inside diameter of 0.313 to 0.318 inches fits standard arbor and shaft sizes in that range
• Outside diameter of 0.495 to 0.505 inches for compact, close-clearance installations
• Arbor-type shim geometry suited for rotating shaft and spindle assemblies
• Pack of 25 shims for job-site use or shop stocking

Compatibility

Designed as an OEM-style precision shim for mechanical assemblies requiring a 0.313 to 0.318 inch bore and a nominal 0.500 inch outside diameter with 0.005 inch thickness adjustment.

Installation Notes

Shim installation is typically performed by machinists, millwrights, or maintenance technicians. Before shimming any rotating assembly, de-energize and lock out the equipment per OSHA lockout/tagout procedures. Clean mating surfaces and verify bore and shaft dimensions with calibrated gauges before selecting shim stack thickness. Do not mix shims of different materials or grades in a single stack unless the application specifically requires it, as differential thermal expansion can alter the final fit.