Overview
The Martin BK50 1 is a fractional horsepower (FHP) sheave designed for light-duty industrial applications requiring reliable V-belt power transmission. This single-groove pulley features a 1″ bore diameter and 4.75″ outside diameter, making it compatible with standard A and B belt sizes including 4L and 5L V-belts. Built by Martin Sprocket & Gear, this sheave combines proven engineering with cost-effective performance for fans, blowers, pumps, and material handling equipment.
Key Features
- Statically balanced for smooth operation and reduced vibration
- Class 30 gray iron construction for durability and extended service life
- Single-groove design compatible with 4L and 5L V-belt sections
- 1″ bored-to-size bore diameter with precision-machined grooves
- Lightweight construction ideal for fractional horsepower drives
- Maximum operating speed of 6,500 fpm for efficient power delivery
Technical Specifications
- Outside Diameter: 4.75 inches
- Bore Diameter: 1 inch (finished bored-to-size)
- Grooves: 1 single groove
- Belt Section: A, B (4L, 5L V-belts)
- Material: Class 30 gray iron
- Tensile Strength: 30,000 psi
- Maximum Speed: 6,500 fpm
- Balancing: Statically balanced
- Pitch Diameter: 4 inches (4L), 4.4 inches (5L)
- Face Width: 7/8 inch
- Standard: ARPM IP20
Typical Applications
The Martin BK50 1 sheave is well-suited for:
- Small fan and blower motors
- Hydraulic pump drives
- Conveyor and material handling systems
- Light-duty industrial machinery
- HVAC equipment and ventilation systems
- Machine tool accessory drives
Compatibility & Replacements
Compatible With
- 4L and 5L V-belt classical and cogged belt designs
- A and B belt section sizes
- Fractional horsepower motors and drives
- Standard V-belt drive systems per ARPM specifications
- QD bushing systems (when equipped with bushings)
Replaces / Drop-In Replacement For
- Gates BK50 1 (equivalent FHP sheave)
- Other ARPM-standard BK50 1-inch bore sheaves from competing manufacturers
- Legacy Martin BK50 1 units requiring replacement
Works With
- Standard 4L and 5L V-belt inventories
- ARPM-compliant drive systems and belt conveyors
- Any OEM equipment using 1″ bore, 4.75″ OD light-duty sheaves
- Belt-driven motor couplings and drive assemblies
