Starrett 52858 Feeler Gage 0.02 in Parallel Leaf 12 in

Product Description

The STARRETT 52858 is a single-leaf feeler gage used to measure and verify precise clearances in mechanical assemblies, engine components, valve trains, and alignment applications. The leaf measures 0.02 inches thick, 0.5 inches wide, and 12 inches long, ground from tempered steel for consistent thickness and long service life. The parallel leaf profile maintains a uniform cross-section along the full length, which is critical when checking consistent gaps across a wide surface. Machinists, millwrights, engine technicians, and HVAC technicians rely on feeler gages like this one for accurate gap verification during installation and maintenance work.

This feeler gage is suited for checking valve clearances, spark plug gaps, bearing clearances, brake shoe clearances, and equipment alignment tolerances in both residential and commercial service environments. The 12-inch leaf length provides reach into deep or recessed assemblies where shorter gages may not access the measurement point. The 0.02-inch thickness covers a commonly specified clearance range found in many mechanical service procedures.

Key Features

• Parallel leaf profile maintains uniform 0.02-inch thickness along the full 12-inch length
• Tempered steel construction resists wear and holds calibrated thickness under repeated use
• 0.5-inch leaf width provides a stable contact surface for consistent readings
• 12-inch length reaches deep or recessed clearance points in mechanical assemblies
• Single-leaf format allows direct insertion without managing a multi-leaf bundle

Compatibility

Designed as a standard-format replacement or service feeler gage leaf for general mechanical, engine, and HVAC service applications requiring a 0.02-inch gap check.

Installation Notes

Power down or de-energize equipment before inserting a feeler gage into any rotating or energized assembly. Clean the contact surfaces before measuring to avoid false readings caused by debris. Apply only light, consistent drag pressure when sliding the leaf through the gap — forcing the leaf can bend it and alter its calibrated thickness. Feeler gage work is typically performed by licensed mechanics, machinists, HVAC technicians, or engine service professionals following manufacturer-specified clearance tolerances.