Spi 91-388-9 Feeler Gauge 0.035 in Parallel Leaf 12 in

Product Description

The SPI 91-388-9 is a parallel-leaf feeler gauge used to measure precise clearances and gaps in mechanical assemblies. Manufactured from high-carbon steel, this gauge delivers the rigidity and wear resistance required for repeated use in demanding shop and field environments. The leaf measures 0.035 inches thick, 0.5 inches wide, and 12 inches long, making it well suited for reaching into tight clearance zones. HVAC technicians, machinists, and industrial mechanics rely on feeler gauges like this one to verify valve clearances, spark plug gaps, bearing fits, and similar precision gap checks.

This gauge is applicable across a broad range of trade and industrial settings, including HVAC service, engine work, pump maintenance, and general mechanical assembly. The 12-inch parallel leaf length provides extended reach for deep or obstructed measurement points. Its 0.035-inch thickness corresponds to a common gap specification found in burner orifice alignment, motor bearing checks, and rotating equipment service tasks performed by licensed technicians and experienced mechanics.

Key Features

• Parallel leaf style for consistent thickness along the full 12-inch length
• High-carbon steel construction for durability and resistance to deformation
• 0.035-inch thickness for precise gap measurement at a widely used specification
• 0.5-inch leaf width provides stable contact surface during measurement
• 12-inch length offers extended reach into confined or deep clearance points

Compatibility

Designed as a general-purpose feeler gauge leaf for use in HVAC, mechanical, and industrial service applications where a 0.035-inch parallel leaf is required.

Installation Notes

Feeler gauges are used by technicians and mechanics to verify clearances without power tools. Always ensure the equipment being measured is powered down, depressurized, or at rest before inserting the gauge leaf. Avoid bending or forcing the leaf into a gap narrower than its rated thickness, as this can permanently deform the blade and compromise accuracy. Clean the leaf after each use to prevent corrosion and maintain measurement integrity.