990PJ/390J Major Brand Poly V Multiple Ribbed Belt 990mm/39 inch Length with 12 Ribs

J Section Poly V Belts 3.6 - 4.5mm depth with 2.34mm pitch between the ribs: The Poly-V belt is a single, endless belt with longitudinal V-shaped ribs that mate perfectly with the V-grooves in the pulleys (sheaves). It combines the convenience of a thin, one-piece flat belt with the strong gripping traction of multiple V-belts to make the Poly-V belt far better for many applications. The approximate belt width is the number of ribs multiplied by 2.34mm
To distribute the drive load evenly across the full width of the sheave, the Poly-V belt is built as a single unit with a completely supported, uninterrupted tension member. There is no belt matching problem, no separate belts to turn over, grab, slip, or interfere with each other.
The thin cross-section profile allows the use of smaller pulleys than standard V-belts and Poly-V belts handle speed ratios of 40:1. With all this capacity, the Poly-V belt tracks properly without special guides, flanges, crowns, or deep grooves and it resists seating in the grooves. Speed ratios remain more consistent and output speed remains more uniform.
Benefits: Oil, heat, ozone, and abrasion-resistant, static conductive.