Overview
The Martin 40BS11-7/8 sprocket is a finished-bore, bored-to-size roller chain sprocket designed for ANSI #40 standard roller chain. These finished bore sprockets are shaft ready and come complete with keyways and setscrews. This 11-tooth sprocket delivers reliable performance in low-to-moderate power motion control applications, offering immediate installation capability without machining or additional hardware.
Key Features
- High carbon steel construction ensures consistent finish and high quality
- Bores are concentric to pitch line, minimizing run out
- Finished bore design with keyways on center line of the tooth
- Two setscrews and full-depth keyway for secure shaft fastening
- Tolerances meet or exceed ANSI standards
- Type BS (bored-to-size) for quick drop-in installation
Technical Specifications
- Chain Type: ANSI #40 Standard Roller Chain
- Number of Teeth: 11
- Chain Pitch: 1/2 inch (0.500″)
- Bore Diameter: 7/8 inch (0.8750″)
- Outside Diameter: 2.003 inches
- Pitch Diameter: 1.775 inches
- Bore Type: Bored-to-Size / Finished Bore
- Hub Configuration: B-Hub (one side extension)
- Hub Diameter: 1-3/8 inches
- Length Through Bore: 7/8 inch
- Material: High Carbon Steel
- Fastening: 2 Setscrews + Full-Depth Keyway
- Keyway Size: 3/16 x 3/32 inch
- Setscrew Size: 1/4-20 x 1/4 inch
- Strand Configuration: Single Strand
- Teeth Hardening: Standard (non-hardened)
Typical Applications
The Martin 40BS11-7/8 is commonly used in:
- Conveyor drive systems and material handling equipment
- Packaging machinery with moderate torque requirements
- Agricultural and lawn equipment drives
- Small motor-driven power transmission systems
- Low-speed, low-horsepower industrial machinery
- Retrofit and replacement applications in existing chain drives
Compatibility & Replacements
Compatible With
- ANSI #40 roller chain (standard single-strand)
- Electric motors with 7/8″ diameter shafts
- Gearbox output shafts matching bore diameter
- Any standard #40 chain drive system
Replaces / Drop-In Replacement For
- Previous Martin 40BS11-7/8 production runs
- OEM applications specifying #40 chain with 11-tooth 7/8″ bore requirement
- Equivalent 11-tooth #40 sprockets from other manufacturers (verify bore and hub configuration)
Works With
- Standard ANSI #40 single-pitch roller chain
- Duplex and triplex chain drives (requires matching tooth count on other sprockets)
- Motor-to-shaft couplings with setscrew interfaces
- Taper bushings and other bored-sprocket mounting systems
