Baldor Electric Company MVL44X7/8 Variable Pitch Adjustable Sheave Pulley Single Groove 7/8 in Bore

The Baldor Electric Company MVL44X7/8 is a single-groove, light-duty variable pitch adjustable sheave (pulley) designed primarily for air handling and HVAC applications. With a 7/8-inch finished bore and 4.15-inch outer diameter, this sheave delivers reliable, field-adjustable speed control for fans, blowers, furnace air handlers, and air conditioning units.

Constructed from durable gray cast iron Class 30, this adjustable pitch sheave provides long-lasting performance in demanding environments. The pitch diameter is easily modified by rotating the adjustable flange on the threaded hub, allowing precise speed tuning without replacing the sheave entirely. Once the desired diameter is set, the adjusting screws on one of the two flat surfaces are tightened to lock the position.

Key Specifications:

• Bore Size: 7/8 inch (0.875 in) finished bore with standard keyway
• Outer Diameter (OD): 4.15 inches
• Hub Width: 1-11/16 inches
• Rim Width: 45/64 inch
• Number of Grooves: 1
• Belt Compatibility: 3L, 4L, 5L, A, and B belt sections (do not use B Gripnotch belt ratings)
• Material: Gray cast iron Class 30
• Maximum Rim Speed: 6,500 feet per minute
• Application Range: Fractional light duty (less than 1 HP) to heavy duty (up to 40 HP)

Key Features:

• Adjustable pitch diameter via threaded flange rotation for easy speed tuning
• Lock-down set screws secure the flange at the desired pitch diameter
• Compatible with standard 3L/4L/5L/A/B V-belt sections
• Statically balanced construction for smooth, vibration-reduced operation
• Ideal for HVAC, fans, blowers, furnace blowers, and air conditioning drives

Important Notes: Do not use these gray cast iron sheaves at rim speeds exceeding 6,500 ft/min. The maximum RPM marked on the sheave arm is based on this speed limit and does not account for dynamic balancing requirements. Also known by the cross-reference part number 1VL44X7/8 (Browning/Dodge).