Star Coupling Manufacturer in Ahmedabad: SJC Size Chart
A star coupling is a jaw-type flexible coupling: two metal hubs joined by a star-shaped elastomer spider that damps vibration and takes minor misalignment without lubrication. Super Mech Industries manufactures star couplings in Ahmedabad in 13 sizes, SJC 75 to SJC 295, rated 9.8 to 1,279 Nm, with finished bores of 10 to 100 mm.
Star Couplings are a type of jaw coupling that use a star-shaped elastomer (also called a spider) to connect two metal hubs. The elastomer insert dampens vibrations, absorbs shock loads, and compensates for minor misalignments, making them ideal for precision and general power transmission applications. Their fail-safe design ensures continued operation even if the elastomer fails, and they operate without the need for lubrication.
Key Features
- Star-shaped elastomer insert for shock absorption
- Compact design with high torsional flexibility
- No lubrication required
- Handles angular and radial misalignments
- Easy assembly and maintenance
Specifications
- Torque Range: 9.8-1,279 Nm (SJC 75 to SJC 295)
- Bore Sizes: 10-100mm (finished bore)
- Speed: Up to 8,000 RPM
- Temperature Range: -40°C to +100°C
- Elastomer Material: Polyurethane (various hardness grades)
Applications
- Pumps and compressors
- Fans and blowers
- Conveyors
- CNC machines and automation equipment
- Packaging and printing machinery
Star coupling size chart: SJC 75 to SJC 295
Every SJC size from the SMI spec sheet, with torque, kW at 100 rpm, finished bore range, outside diameters, length and weight. Bores are finished to your shaft within the listed range.
Star (jaw) couplings SJC — ratings and dimensions
Sizes SJC 75 to SJC 295. Torque in Nm; power at 100 rpm; finished bore range and dimensions in mm; weight in kg.
| Size | Torque (Nm) | kW at 100 rpm | Bore min (mm) | Bore max (mm) | ØA (mm) | ØB (mm) | L (mm) | Weight (kg) |
|---|---|---|---|---|---|---|---|---|
| SJC 75 | 9.8 | 0.10 | 10 | 20 | 44.5 | 39 | 55 | 0.5 |
| SJC 90 | 15.5 | 0.15 | 15 | 28 | 54 | 49 | 56 | 0.7 |
| SJC 95 | 21.1 | 0.22 | 15 | 28 | 54 | 49 | 63 | 0.8 |
| SJC 99 | 35.1 | 0.37 | 20 | 35 | 65 | 57 | 72 | 1.5 |
| SJC 100 | 46.4 | 0.49 | 20 | 35 | 65 | 57 | 88 | 1.5 |
| SJC 110 | 89 | 0.93 | 20 | 45 | 85 | 76 | 108 | 3.0 |
| SJC 150 | 141 | 1.49 | 30 | 48 | 96 | 80 | 115 | 3.7 |
| SJC 190 | 190 | 2.01 | 36 | 60 | 115 | 102 | 133 | 6.8 |
| SJC 225 | 265 | 2.75 | 40 | 65 | 127 | 111 | 153 | 9.1 |
| SJC 226 | 327 | 3.45 | 25 | 70 | 137 | 119 | 178 | 12.0 |
| SJC 276 | 532 | 5.60 | 25 | 75 | 157 | 127 | 200 | 18.0 |
| SJC 280 | 782 | 8.20 | 30 | 85 | 192 | 140 | 200 | 24.0 |
| SJC 295 | 1279 | 13.40 | 40 | 100 | 237 | 162 | 238 | 44.0 |
- SJC 99: the spec sheet prints the weight as “.1.5”; it is shown as 1.5 kg.
Source: SMI spec sheet star-coupling.pdf.
Frequently Asked Questions
What is a star coupling?
A star coupling is a jaw-type flexible coupling. Two metal hubs with jaws are joined by a star-shaped elastomer insert, also called a spider, which damps vibration, absorbs shock loads and compensates for minor misalignment. It needs no lubrication.
How do I choose a star coupling size from the size chart?
Work out the drive torque, T (Nm) = 9550 × kW ÷ rpm, multiply it by the service factor for the load, then take the first SJC size whose torque rating is higher and whose bore range fits both shafts. For example, a 7.5 kW motor at 1,440 rpm gives about 49.7 Nm; with a service factor of 1.5 (typical for conveyors and mixers) the design torque is about 74.6 Nm, so SJC 110 (89 Nm, bores 20 to 45 mm) is the first size that covers it.
Is the SMI star coupling an equivalent for Lovejoy L-type jaw couplings?
SMI's star coupling is offered as an alternative to standard L-type jaw couplings. Before ordering, confirm hub outside diameter, length, bore and spider type against your existing coupling, because dimensions and spider hardness vary between makers. Brand names are used for compatibility reference only.
What happens if the elastomer fails?
The design is fail-safe: the coupling continues to operate even if the elastomer insert fails. It runs without lubrication.
Where are star couplings used?
Typical applications are pumps and compressors, fans and blowers, conveyors, CNC machines and automation equipment, and packaging and printing machinery.
Where does SMI make star couplings?
At its factory in Odhav, Ahmedabad, Gujarat. Super Mech Industries is ISO 9001:2015 certified (Certificate No. 09114716A), holds ZED certification and exports to 29 countries; bores are finished to your shaft within each size's range.
What sizes of Star Coupling does SMI manufacture?
SMI lists 13 sizes from SJC 75 to SJC 295 rated from 9.8 Nm to 1,279 Nm, with bores finished up to 100 mm. The full size chart with dimensions is on this page and on the spec sheet.
Exported from Ahmedabad to 29 countries
Super Mech Industries exports from Ahmedabad, India to 29 countries, shipping from Mundra Port (Gujarat) or JNPT (Nhava Sheva, Mumbai).
Super Mech Industries — Odhav, Ahmedabad, Gujarat 382415, India. Phone: +91 63510 70577. Email: smigvs@gmail.com. ISO 9001:2015 certified.