Overview
The Martin SK 1-7/8 quick disconnect bushing is a cast iron QD bushing engineered for reliable pulley, sheave, and sprocket mounting on drive shafts. Class 30 gray cast iron construction provides durability and resistance to wear, galling, and corrosion. The split flange and tapered design enable strong clamping without requiring additional components, making this bushing ideal for power transmission applications across manufacturing, construction, and material handling equipment.
Key Features
- Cast iron construction (Class 30 gray) for wear and corrosion resistance
- Quick-disconnect (QD) design enables rapid pulley and sheave changes
- Split flange with taper for positive shaft clamping
- Finished bore with 1/2 x 1/4 inch keyway to prevent shaft rotation
- Set screw over keyway for secure mounting on vertical shafts and vibrating loads
- Three bolt holes for secure flange fastening
Technical Specifications
- Bore Diameter: 1-7/8 inch (1.8750 in)
- Keyway Size: 1/2 x 1/4 inch
- Barrel Diameter: 2.812 inch
- Flange Outside Diameter: 3.875 inch
- Flange Thickness: 0.5625 inch
- Length Through Bore: 1.9375 inch
- Bolt Circle Diameter: 3-5/16 inch
- Number of Bolt Holes: 3
- Screw Thread Size: 5/16-18 inch
- Screw Length: 2 inch
- Screw Torque: 180 inch-pounds
- Material: Class 30 gray cast iron
- Manufacturer Catalog Number: 120145
Typical Applications
The Martin SK 1-7/8 bushing is suitable for mounting quick-disconnect pulleys and sheaves in:
- Industrial power transmission systems
- Conveyor belt drives and chain drives
- Machine tool spindle and motor mounts
- Fans, blowers, and pump drives
- Construction and mining equipment
- Agricultural machinery
Compatibility & Replacements
Compatible With
- Martin QD (quick-disconnect) pulleys and sheaves
- Sprockets compatible with SK-series bushings
- Standard shaft diameters: 1-7/8 inch bore shafts
- ANSI (American National Standards Institute) standard power transmission systems
- Conventional and reverse bushing mounting configurations
Replaces / Drop-In Replacement For
Verify compatibility with your system integrator before ordering. The Martin SK 1-7/8 is part of the SK series QD bushing family and may serve as a replacement for other equivalent 1-7/8 inch bore quick-disconnect bushings in similar applications.
Works With
- Martin power transmission components and accessories
- Standard shaft keyways (1/2 x 1/4 inch)
- Flange-mounted QD pulleys and sprockets
- 3-bolt flange configurations
- Industrial motor and drive systems
