HercuFlex® Rigid Adjustable Couplings (RA & RAHS)
The RA and RAHS couplings are offered in two different styles. Type II coupling consists of two rigid hubs, adjusting nut and split ring and split ring for motor bub. Type IV coupling consists of two rigid hubs, adjusting nut, split ring for motor hub and spacer.
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Axial positioning of the pump impeller in vertical pump applications
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Clearance fit bores allows for easy installation and maintenance for pump and/or motor
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Easily adjustable for vertical clearance
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Removable spacer for easy maintenance
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AISI 1045 Steel (Stainless Steel coupling also available)

Resources
HercuFlex® Rigid Adjustable Couplings (RA & RAHS) Additional Resources
Note: Performance Data below is for Standard RA & RAHS Series only. Please download catalog for dimensional data, and for performance data on other HercuFlex type gear couplings.
Size | HP/100 RPM |
Nominal Torque (in-lbs) |
Thrust Capacity (lbs) |
Min Bore (in) |
Min Bore (mm) |
Max Bore (in) |
Max Bore (mm) |
1125 | 2.7 | 1,702 | 4,500 | 0.44 | 11 | 1.125 | 29 |
1625 | 8.0 | 5,042 | 11,000 | 0.63 | 16 | 1.625 | 42 |
2125 | 17.9 | 11,282 | 31,000 | 0.73 | 18 | 2.125 | 56 |
2625 | 33.8 | 21,302 | 31,000 | 0.88 | 22 | 2.625 | 70 |
2875 | 44.4 | 27,983 | 31,000 | 0.88 | 22 | 2.875 | 77 |
3125 | 57.0 | 35,924 | 41,000 | 1.19 | 30 | 3.125 | 84 |
3875 | 109.0 | 68,697 | 73,000 | 1.25 | 31 | 3.875 | 103 |
5000 | 310.0 | 195,378 | 160,000 | 2.38 | 60 | 5.000 | 135 |
6000 | 404.0 | 254,621 | 300,000 | 2.88 | 73 | 6.000 | 167 |
7250 | 712.0 | 448,738 | 300,000 | 4.00 | 101 | 7.250 | 194 |
8500 | 1148.0 | 723,527 | 350,000 | 4.00 | 101 | 8.500 | 225 |
10500 | 2164.0 | 1,363,861 | 400,000 | 5.00 | 127 | 10.500 | 276 |
- For HercuFlex Flange Sleeve Gear Coupling: see HercuFlex FX Series
- For HercuFlex Continuous Sleeve Gear Coupling: see HercuFlex CX Series
- For Lovejoy’s Legacy Sier Bath Gear Couplings: see Lovejoy / Sier Bath Gear Couplings
- For High Speed: see High Performance Gear Couplings
- For Large Jaw Coupling: see H Type
- For “Infinite Life”: see Disc Couplings
- Or, for other coupling types: see Coupling Preselection Guide