Description
TS7-40 Setscrew Rigid Coupling – 40 mm OD Aluminum Alloy High-Torque Miniature Coupler
The TS7-40 setscrew type rigid coupling is the largest and highest-torque aluminum alloy model in the TS7 series. With a 40 mm outer diameter, a bore range extending from 14 to 20 mm, and a nominal torque rating of 5 N·m, it bridges the gap between miniature precision couplings and the standard industrial coupling range. The upgrade to M5 setscrew threading at this frame size reflects the increased clamping force requirement for reliable torque transmission at 5 N·m. The specified wrench torque of 1.7 N·m for M5 setscrews must be observed with a calibrated torque tool to avoid bore surface deformation on smaller shafts within the available range.
At 100 g total mass and 9.1 × 10⁻⁶ kg·m² rotational inertia (at maximum 20 mm bore), the TS7-40 remains a genuine miniature coupling by mass, but its torque rating places it in the operating range of medium-frame servo motors and compact gearbox outputs. Maximum rotational speed of 8,000 rpm is suited to direct servo motor output shaft connections and gearbox output connections where motor-side speed is reduced. The stainless steel STS7-40 (210 g) provides equivalent performance for corrosion-exposed environments.
A full comparison of TS7 frame sizes, torque ratings, and bore ranges is available on our product catalog.
Technical Specifications
| Parameter | Value |
|---|---|
| Model | TS7-40 |
| Body Material | Aluminum Alloy |
| Outer Diameter (D) | 40 mm |
| Overall Length (L) | 50 mm |
| Hub Length (L1) | 12 mm |
| Available Bore Sizes | 14, 16, 18, 19, 20 mm |
| Setscrew Thread | M5 |
| Wrench Torque | 1.7 N·m |
| Rated Torque | 5 N·m |
| Maximum Torque | 10 N·m |
| Maximum Rotational Speed | 8,000 rpm |
| Moment of Inertia | 9.1 × 10⁻⁶ kg·m² |
| Mass | 100 g |
Dimension Drawing
Performance and Installation Notes
The 12 mm hub length per side on the TS7-40 — the longest hub in the TS7 aluminum series — provides sufficient shaft engagement for reliable 5 N·m torque transmission. For shafts at the lower end of the bore range (14–16 mm), the wall thickness ratio is adequate for the clamping loads involved. At 19 and 20 mm bore with the 40 mm OD, the remaining wall section is thinner; for these bore sizes, applications should stay within the rated 5 N·m rather than approaching the 10 N·m maximum continuously.
Shaft flatted to DIN or equivalent is strongly recommended for the TS7-40 across all bore sizes when operating near rated torque. The M5 setscrew contact area remains a small fraction of the shaft circumference at 20 mm bore, and the flat substantially improves clamping effectiveness.
Application Areas
- 750 W to 1.5 kW servo motor output shafts coupled to ball screw or rack-and-pinion drives on machining centres
- Compact gearbox output coupling — planetary gearhead to driven shaft connections in material handling
- Precision rotary table index drives — angular indexing systems in assembly and inspection automation
- Hydraulic servo valve feedback shafts — spool position encoder connections
- Wind tunnel model positioning drives — aerodynamic test rigs with high positional accuracy requirements
Customer Reviews and Case Studies
★★★★★
Czech Republic — Machine Tool Manufacturer
We use the TS7-40 to couple servo motors to ball screws on our precision grinding machine Y-axis. The coupling handles the rated operating torque without slip and has maintained its zero-backlash performance over two years of three-shift production. Batch dimensional consistency has been reliable across multiple orders.
— Chief Engineer, Brno
★★★★★
Singapore — Semiconductor Equipment OEM
Specified for wafer handling robot axis drives. The 18 mm bore matched our servo gearhead output shaft exactly. The coupling’s low mass was important for our moving-axis mass budget. Technical data was accurate and the pre-sales team confirmed compatibility with our servo amplifier inertia ratio requirement.
— Mechanical Design Engineer, Singapore
★★★★☆
France — Automation Integrator
Used in a custom rotary indexing table drive. The TS7-40 with a 20 mm bore performed well at the specified 4 N·m operating torque. We applied a shaft flat on our motor shaft as recommended, which resolved a minor slippage issue observed during initial commissioning at peak torque. Satisfied with the product and the technical guidance provided.
— Application Engineer, Lyon
Frequently Asked Questions
What bore sizes are available for the TS7-40?
The TS7-40 accepts 14, 16, 18, 19, and 20 mm bores on each side. Mixed-bore combinations are available. Specify your d1 and d2 bore diameters when enquiring.
Is a shaft flat recommended for the TS7-40?
Yes, strongly recommended for all bore sizes at or near rated torque. The M5 setscrew contact area on a 20 mm shaft is a small fraction of the shaft circumference, and a machined flat substantially improves grip while protecting the shaft from point indentation.
What is the difference between rated and maximum torque?
Rated torque (5 N·m) is the continuous operating value — design your application to this figure for sustained duty. Maximum torque (10 N·m) is the peak dynamic value — acceptable for brief transient loads such as acceleration peaks, but not for continuous operation.
Is the STS7-40 stainless version available?
Yes. The STS7-40 in 316 stainless steel is dimensionally identical to the TS7-40 with the same torque, speed, and bore specifications. The stainless version weighs 210 g versus 100 g for aluminum. Specify STS7-40 for food, pharmaceutical, marine, or chemical washdown environments.
What shaft tolerance should I use with the TS7-40?
h6 is the preferred shaft tolerance for all TS7-40 bore sizes. Tighter tolerances (h5) improve bore contact but may require careful shaft insertion. Avoid loose tolerances (h8 or above) at this torque level — reduced contact area lowers the effective torque holding capacity significantly.
Request Pricing for the TS7-40 Rigid Coupling
Ever Power supplies the TS7-40 and the complete TS7 aluminum alloy series direct from our factory. Provide your bore requirements, quantity, and application — we respond with technical confirmation and competitive pricing.
