CAT 4H-1566 26.974mm Thick Spacer

CAT 4H-1566 is a genuine Caterpillar flat gasket (steel gasket for positioning/adjustment), commonly used in static connections of engines and transmission systems for sealing, positioning, and gap adjustment. The following are precise original factory specifications and application information; replacement parts are not included.

Core Technical Parameters

Item Details
Part Model: CAT 4H-1566 (Flat Washer / Steel Washer)
Material: S45C carbon structural steel, tempered, hardness 22–28 HRC; galvanized and passivated surface, no white rust after 96 hours of salt spray testing

Key Dimensions: Inner diameter 19 mm (0.748 in), outer diameter 30 mm (1.181 in), thickness 2 mm (0.0787 in), edge chamfer 0.3×45°

Performance Parameters: Tensile strength 600–750 MPa, yield strength ≥ 355 MPa, Brinell hardness 170–230 HB, operating temperature -40℃ ~ +200℃, flatness ≤ 0.02 mm, parallelism ≤ 0.03 mm

Unit Weight: Approx. 0.0082 kg (0.0181 lbs)

Tolerance Standard: Inner diameter tolerance +0.10/-0.05 mm, outer diameter tolerance ±0.10 mm, thickness tolerance ±0.05 mm, surface roughness Ra ≤ 1.6 μm

Surface Treatment: Zinc plating and passivation enhance corrosion resistance, suitable for harsh working conditions such as dust and humidity in engineering machinery.

Structure and Core Characteristics:

Flat Gasket Structure: Utilizes a circular flat plate design without special cuts or grooves, ensuring a smooth surface. It fills the tiny gaps between two connecting surfaces, guaranteeing connection sealing and positioning accuracy. It also allows for adjustment of component assembly gaps to adapt to different working conditions.

High Strength and Stability: S45C carbon structural steel undergoes quenching and tempering, possessing excellent strength and toughness. It can withstand bolt tightening pressure, is not easily deformed or broken, and ensures long-term stable operation.

Precise Fit: Strict dimensional tolerances and surface flatness requirements ensure a tight fit with the connecting surfaces after installation, effectively preventing leakage, ensuring accurate component positioning, and improving system operational stability.

Corrosion-resistant design: Galvanized passivated surface treatment resists corrosive media such as moisture and dust in the working environment, extending service life and reducing maintenance frequency.

Compatible Models and Application Scenarios

Compatible Equipment: CAT 320D/323D excavators, 950H/966H loaders, C7.1/C9.3 engines, 140M graders, etc.

Core Uses: Used for static sealing and clearance adjustment in engine cylinder heads, oil pans, gearbox housings, hydraulic pump housings, etc., preventing oil, water, and gas leaks. It also assists in positioning components to ensure assembly accuracy, suitable for medium to heavy-duty operating conditions.

Installation and Maintenance Points

Installation: Clean the connecting surfaces, removing burrs, oil, and rust. Inspect the gaskets for defects such as deformation, cracks, and scratches, ensuring the surface is flat.

Place the gaskets correctly between the connecting surfaces, ensuring alignment with the bolt holes without misalignment to avoid affecting the sealing effect and positioning accuracy.

Tighten the bolts to the specified torque and follow a symmetrical, cross-tightening sequence to prevent uneven force on the gaskets, which could lead to leakage or damage.