Martin Hi-Cap 3V wedge sheaves are precision-machined power transmission components designed for 3V narrow-profile V-belt systems. The Hi-Cap design provides maximum belt contact and load distribution in a compact envelope, delivering higher horsepower ratings per groove than conventional sheaves of the same diameter. Every Martin Hi-Cap sheave is manufactured from high-strength cast iron, dynamically balanced to minimize vibration, and machined to MPTA standards for groove dimensions and concentricity.

The QD (Quick Detachable) bushing system allows fast, tool-free installation and removal without disturbing alignment. The tapered bushing creates a uniform clamping force that locks the sheave concentrically on the shaft — no setscrews to damage the shaft, no wobble from bore clearance. When it’s time for maintenance, loosen the cap screws and the bushing releases cleanly. Available in pitch diameters from 2.20” to 25.00” with 1 through 10 grooves, covering the full range of 3V belt drive applications from fractional-horsepower fans to heavy industrial compressors.

QD bushing sizes scale with sheave diameter: JA bushings for the smallest sheaves (max bore 1.25”), progressing through SH, SDS, SK, SF, E, F, and J for the largest diameters. Each sheave listing includes the required bushing type — order the bushing separately matched to your shaft bore size.

• 3V Wedge Belt Section — narrow profile for higher speed and horsepower capacity
• Hi-Cap Groove Design — deeper groove contact for superior belt grip and load transfer
• QD Bushing Mount — fast installation/removal, concentric clamping, no shaft damage
• 1 to 10 Grooves — match groove count to your horsepower and belt requirements
• 2.20” to 25.00” Pitch Diameter — full range for speed ratio flexibility
• Cast Iron Construction — high strength, excellent vibration damping, long service life
• Dynamically Balanced — smooth operation at rated speeds
• MPTA Standards — groove dimensions and concentricity per industry specifications
• Bushing Sold Separately — select the QD bushing bore that matches your shaft