KP-AK / KP-K / W-AK / P-K / PD-K / P Series

Overview of KP-AK, KP-K, W-AK, P-K, PD-K, and P- Series Bearings

The KP-AK, KP-K, W-AK, P-K, PD-K, and P- series are precision-engineered airframe control ball bearings optimized for aerospace pulley systems. These bearings are available in single-row and double-row configurations and are designed to support rotational and oscillatory motion in aircraft flight control systems. Their structural integrity and material composition make them ideal for environments requiring long service life, low maintenance, and compliance with military specifications.

Key Features and Specifications

Material: Inner and outer rings, as well as balls, are manufactured from high-grade AISI 52100 chrome steel, known for its excellent hardness and fatigue resistance.
Temperature Range: Designed to perform reliably in extreme aerospace conditions, these bearings operate within a wide range of -65°F to +250°F (-54°C to +121°C).
Sealing System: All models include removable PTFE (polytetrafluoroethylene) seals, offering excellent chemical resistance and low friction for smooth operation.
Lubrication: Bearings come pre-lubricated with MIL-PRF-81322 aerospace grease, with a standard fill of 80% unless otherwise specified by the customer. This grease offers superior protection against oxidation, corrosion, and moisture.
Surface Treatment: External surfaces (excluding the bore) are cadmium plated in accordance with AMS-QQ-P-416 specifications, providing effective corrosion resistance and enhanced durability. All critical dimensions apply after plating.
Customization: Upon request, we can supply custom configurations to meet specific design requirements, including special sizes, materials, internal clearances, lubrication types, and plating options.
Measurement Units: All standard dimensional values are expressed in inches unless noted otherwise.

Applications in Aerospace Systems

These pulley-type airframe control bearings are typically used in aircraft control cable systems, flap and slat mechanisms, and other linkage assemblies that require both low-friction movement and high radial load capacity. Their dual-row variants offer improved load handling where space permits.

Compliance with Aerospace Standards

This bearing series meets stringent aerospace quality and performance criteria. Lubrication and plating conform to recognized U.S. military specifications such as:

MIL-PRF-81322: Specification for general-purpose aerospace grease.
AMS-QQ-P-416: Cadmium plating specification ensuring corrosion resistance and surface durability.

Why Choose These Bearing Series?

The KP-AK through P- series airframe control ball bearings offer a reliable solution for engineers and OEMs who need precision, durability, and certification-ready components. Whether used in commercial aircraft, defense aviation, or advanced aerospace assemblies, these bearings deliver consistent performance under dynamic load and environmental extremes.