Caliso 635K4 Poly V Serpentine Belt K-Section - 4-Rib 63.5in

The Caliso 635K4 is a K-Section Poly V serpentine belt (also known as a micro-rib or multi-rib belt) featuring a 4-rib profile and a 63.5-inch pitch length. Designed as a direct OEM-equivalent replacement, this belt delivers reliable power transfer across engine accessory drive systems including alternators, power steering pumps, water pumps, and air conditioning compressors.

Key Specifications:

• Belt Type: Poly V / Serpentine (K-Section, Micro-Rib)
• Part Number: 635K4
• Number of Ribs: 4
• Pitch Length: 63.5 inches
• Rib Profile: K-Section (SAE standard, 3.56mm rib width)
• Construction: EPDM rubber compound with polyester fiber tensile members
• Temperature Range: -30°F to 140°F

Key Features:

• Straight ribbed design for quiet, smooth operation
• Highly flexible construction for compatibility with small-diameter pulleys
• Abrasion, oil, and chemical resistant EPDM compound
• Polyester tensile cords resist stretching and minimize slippage
• Meets or exceeds OEM replacement specifications

The 635K4 Poly V belt is also commonly cross-referenced using the metric PK designation (4PK1613). It is compatible with standard K-section serpentine belt systems and can be cross-referenced against equivalent belts from Gates, Dayco, Goodyear, Bando, and NAPA using the K4 rib profile and 63.5-inch pitch length.