Product Description
Martin - Quadra-Flex® Type J Coupling Flange
Martin Sprocket & Gear — 57 Configurations
Martin couplings connect rotating shafts while accommodating misalignment, absorbing shock loads, and dampening vibration between the driver and driven equipment. Whether you’re connecting a motor to a pump, gearbox to a conveyor, or any other power transmission application, the right coupling protects both components from the forces that cause premature bearing failure, shaft fatigue, and seal leaks.
Martin Sprocket & Gear has been manufacturing couplings and power transmission components in the USA since 1928. Their coupling line includes jaw couplings, Quadra-Flex® elastomeric couplings, and gear couplings — each designed for specific torque ranges, misalignment tolerances, and operating conditions.
Available in 57 configurations (QFJ-3J-PB, QFJ-3J-3/8, QFJ-3J-11MM, QFJ-3J-12MM, QFJ-3J-1/2 and 52 more) for professional power transmission applications.
- Misalignment Accommodation — handles angular, parallel, and axial shaft misalignment
- Shock Absorption — elastomeric elements dampen vibration and protect connected equipment
- Easy Maintenance — replace flex elements without moving motors or driven equipment
- Multiple Bore Options — available in standard and metric bore sizes with keyways
- USA Heritage — Martin Sprocket & Gear, manufacturing since 1928
| SKU | Size | Bore | Type | Element |
|---|---|---|---|---|
| 3J - 78 in-lb - 9,200 RPM (12) | ||||
| QFJ-3J-PB | 3J - 78 in-lb - 9,200 RPM | Pilot Bore | Type J | Hytrel Element |
| QFJ-3J-3/8 | 3J - 78 in-lb - 9,200 RPM | 3/8" - 0.38in - 9.52mm | Type J | Hytrel Element |
| QFJ-3J-11MM | 3J - 78 in-lb - 9,200 RPM | 11mm - 0.43in | Type J | Hytrel Element |
| QFJ-3J-12MM | 3J - 78 in-lb - 9,200 RPM | 12mm - 0.47in | Type J | Hytrel Element |
| QFJ-3J-1/2 | 3J - 78 in-lb - 9,200 RPM | 1/2" - 0.50in - 12.70mm | Type J | Hytrel Element |
| QFJ-3J-14MM | 3J - 78 in-lb - 9,200 RPM | 14mm - 0.55in | Type J | Hytrel Element |
| QFJ-3J-15MM | 3J - 78 in-lb - 9,200 RPM | 15mm - 0.59in | Type J | Hytrel Element |
| QFJ-3J-5/8 | 3J - 78 in-lb - 9,200 RPM | 5/8" - 0.62in - 15.88mm | Type J | Hytrel Element |
| QFJ-3J-16MM | 3J - 78 in-lb - 9,200 RPM | 16mm - 0.63in | Type J | Hytrel Element |
| QFJ-3J-19MM | 3J - 78 in-lb - 9,200 RPM | 19mm - 0.75in | Type J | Hytrel Element |
| QFJ-3J-3/4 | 3J - 78 in-lb - 9,200 RPM | 3/4" - 0.75in - 19.05mm | Type J | Hytrel Element |
| QFJ-3J-7/8 | 3J - 78 in-lb - 9,200 RPM | 7/8" - 0.88in - 22.22mm | Type J | Hytrel Element |
| 4J - 156 in-lb - 7,600 RPM (14) | ||||
| QFJ-4J-PB | 4J - 156 in-lb - 7,600 RPM | Pilot Bore | Type J | Hytrel Element |
| QFJ-4J-1/2 | 4J - 156 in-lb - 7,600 RPM | 1/2" - 0.50in - 12.70mm | Type J | Hytrel Element |
| QFJ-4J-14MM | 4J - 156 in-lb - 7,600 RPM | 14mm - 0.55in | Type J | Hytrel Element |
| QFJ-4J-15MM | 4J - 156 in-lb - 7,600 RPM | 15mm - 0.59in | Type J | Hytrel Element |
| QFJ-4J-5/8 | 4J - 156 in-lb - 7,600 RPM | 5/8" - 0.62in - 15.88mm | Type J | Hytrel Element |
| QFJ-4J-16MM | 4J - 156 in-lb - 7,600 RPM | 16mm - 0.63in | Type J | Hytrel Element |
| QFJ-4J-19MM | 4J - 156 in-lb - 7,600 RPM | 19mm - 0.75in | Type J | Hytrel Element |
| QFJ-4J-3/4 | 4J - 156 in-lb - 7,600 RPM | 3/4" - 0.75in - 19.05mm | Type J | Hytrel Element |
| QFJ-4J-20MM | 4J - 156 in-lb - 7,600 RPM | 20mm - 0.79in | Type J | Hytrel Element |
| QFJ-4J-7/8 | 4J - 156 in-lb - 7,600 RPM | 7/8" - 0.88in - 22.22mm | Type J | Hytrel Element |
| QFJ-4J-15/16 | 4J - 156 in-lb - 7,600 RPM | 15/16" - 0.94in - 23.81mm | Type J | Hytrel Element |
| QFJ-4J-24MM | 4J - 156 in-lb - 7,600 RPM | 24mm - 0.94in | Type J | Hytrel Element |
| QFJ-4J-25MM | 4J - 156 in-lb - 7,600 RPM | 25mm - 0.98in | Type J | Hytrel Element |
| QFJ-4J-1 | 4J - 156 in-lb - 7,600 RPM | 1" - 1.00in - 25.40mm | Type J | Hytrel Element |
| 5J - 312 in-lb - 7,600 RPM (9) | ||||
| QFJ-5J-PB | 5J - 312 in-lb - 7,600 RPM | Pilot Bore | Type J | Hytrel Element |
| QFJ-5J-1/2 | 5J - 312 in-lb - 7,600 RPM | 1/2" - 0.50in - 12.70mm | Type J | Hytrel Element |
| QFJ-5J-5/8 | 5J - 312 in-lb - 7,600 RPM | 5/8" - 0.62in - 15.88mm | Type J | Hytrel Element |
| QFJ-5J-3/4 | 5J - 312 in-lb - 7,600 RPM | 3/4" - 0.75in - 19.05mm | Type J | Hytrel Element |
| QFJ-5J-7/8 | 5J - 312 in-lb - 7,600 RPM | 7/8" - 0.88in - 22.22mm | Type J | Hytrel Element |
| QFJ-5J-15/16 | 5J - 312 in-lb - 7,600 RPM | 15/16" - 0.94in - 23.81mm | Type J | Hytrel Element |
| QFJ-5J-1 | 5J - 312 in-lb - 7,600 RPM | 1" - 1.00in - 25.40mm | Type J | Hytrel Element |
| QFJ-5J-1-1/16 | 5J - 312 in-lb - 7,600 RPM | 1-1/16" - 1.06in - 26.99mm | Type J | Hytrel Element |
| QFJ-5J-1-1/8 | 5J - 312 in-lb - 7,600 RPM | 1-1/8" - 1.12in - 28.57mm | Type J | Hytrel Element |
Where Martin Couplings Connect the Drive
- Pump Systems — motor-to-pump connections on centrifugal, positive displacement, and submersible pump drives
- Conveyor Systems — motor-to-gearbox and gearbox-to-head-shaft connections on belt and roller conveyors
- Agricultural Equipment — irrigation pumps, grain handling drives, and PTO-to-implement connections
- HVAC Systems — fan drives, chiller compressors, and cooling tower motors
- General Industrial — mixers, agitators, generators, and any motor-to-load connection requiring misalignment accommodation
1 All dimensions follow the Lambear tri-format: Imperial fraction – Decimal inches – Metric (mm).
2 Specifications are catalog values. Contact us for application-specific recommendations.