Multiple Ribs, One Continuous Belt
A Poly-V (also called multi-rib or micro-V) pulley carries several narrow, parallel V-shaped grooves across a single wide belt, instead of one deep groove per belt as on a conventional V-belt pulley. The larger combined contact area lets one continuous serpentine belt drive several accessories — alternator, power steering pump, A/C compressor, water pump — off a single crankshaft pulley, with less belt slip and a smaller overall drive package.
JBMK produces Poly-V grooves using precision fine-stamping and CNC flow-forming, holding pitch and groove-angle tolerances tight enough to keep belt wear and drive noise (NVH) within OEM limits across the full production run, not just on first-off samples.
PK / H Profile Options
Standard PK4 through PK8 rib counts, with custom rib pitch available to match your belt spec.
Groove Angle Control
Tight profiling tolerance for even belt-load distribution across every rib.
High-Speed Stability
Balanced for accessory-drive speeds up to 18,000 RPM without induced vibration.
IATF 16949 Certified
Produced under the same automotive quality system as our OEM crankshaft and alternator pulleys.
