Description
STS7-32 Stainless Steel Setscrew Rigid Coupling – 32 mm OD 316SS High-Torque Corrosion-Resistant Coupler
The STS7-32 is the 316 stainless steel version of the TS7-32, delivering 2 N·m rated torque at up to 10,000 rpm through a 32 mm OD body with bore range of 12 to 16 mm. As with all STS7 variants, the performance parameters are identical to the corresponding aluminum TS7 model — only the material changes. The STS7-32 is specified when medium servo motor connections (the 12–16 mm bore class, 2 N·m torque class) must be made in an environment that would corrode or degrade aluminum: food processing, dairy, chemical plant, marine automation, and pharmaceutical production environments all fall into this category.
The STS7-32 weighs 190 g versus 71 g for the TS7-32. The moment of inertia is 2.4 × 10⁻⁶ kg·m². For most servo motor shaft connections in this torque class (typically 400–750 W servo motors), this inertia addition represents a small fraction of the load-side inertia reflected to the motor shaft, and servo loop stability is not affected. The M4 setscrew thread and 1.7 N·m wrench torque are unchanged from the aluminum version.
Material traceability documentation — mill certificates confirming 316 stainless composition — is available on request, supporting procurement for offshore, food safety, and pharmaceutical regulated applications. See our full product catalog for all STS7 stainless rigid coupling models.
Technical Specifications
| Parameter | Value |
|---|---|
| Model | STS7-32 |
| Body Material | 316 Stainless Steel |
| Outer Diameter (D) | 32 mm |
| Overall Length (L) | 41 mm |
| Hub Length (L1) | 10 mm |
| Available Bore Sizes | 12, 14, 15, 16 mm |
| Setscrew Thread | M4 |
| Wrench Torque | 1.7 N·m |
| Rated Torque | 2 N·m |
| Maximum Torque | 4 N·m |
| Maximum Rotational Speed | 10,000 rpm |
| Moment of Inertia | 2.4 × 10⁻⁶ kg·m² |
| Mass | 190 g |
Dimension Drawing
Corrosion Resistance in Practice
At the 32 mm frame size, the STS7-32 is frequently installed in food processing conveyor drives, dairy washdown zones, and chemical plant instrumentation where the daily or weekly environment would rapidly attack an aluminum coupling surface. The 316 stainless body maintains dimensional integrity and surface finish through CIP cycles, steam cleaning, and solvent wipe-downs without the surface pitting, oxidation, or material removal that compromises coupling performance and service life in aluminum. This durability directly reduces coupling replacement frequency and unplanned maintenance in continuous-production environments.
Typical Applications
- Servo encoder connections on stainless washdown conveyor drives in meat, fish, and dairy processing
- Chemical dosing pump servo drives in acid or alkali vapour-exposed plant rooms
- Offshore winch and handling equipment encoder connections with salt spray and humidity exposure
- Marine hydraulic servo valve feedback shafts where stainless is required by classification rules
- Pharmaceutical lyophiliser drive encoder connections in CIP-qualified equipment
Customer Reviews and Case Studies
★★★★★
Ireland — Dairy Processing Equipment
We produce automated dairy filling lines and specified the STS7-32 for servo encoder connections in the filling zone. Chlorinated CIP runs three times daily — only 316SS is acceptable. The coupling has performed without corrosion or mechanical issues across two production seasons.
— Project Engineer, Cork
★★★★★
Norway — Marine Systems Integrator
Used in servo-driven deck winch encoder feedback on a PSV. Classification required stainless material for all encoder components on deck. STS7-32 met the material requirement and dimensions matched our installation exactly. Now our standard model for all similar applications.
— Systems Engineer, Stavanger
★★★★☆
Brazil — Chemical Plant Maintenance
Replacement couplings for HCl vapour-exposed dosing pump servo drives. Previous aluminum couplings failed within weeks. The STS7-32 has been operating 10 months without corrosion. The 14/16 mm bore combination matched without modification.
— Maintenance Supervisor, São Paulo
Frequently Asked Questions
What makes 316SS better than 304SS for the STS7-32?
316 stainless contains molybdenum, which 304 does not. Molybdenum provides significantly improved chloride pitting resistance — the most common corrosion failure mode in food washdown, marine, and chemical environments. For chloride exposure, always specify 316 over 304.
Is the STS7-32 heavier than the TS7-32?
Yes. The STS7-32 weighs 190 g versus 71 g for the TS7-32 aluminum version. This mass increase should be considered in moving-axis inertia calculations.
Can the STS7-32 be autoclaved?
316 stainless steel withstands standard autoclave cycles at 134°C and 2.1 bar without structural change. For medical device applications requiring autoclave sterilisation, confirm with your specific sterilisation protocol requirements.
Are the bores of the STS7-32 interchangeable between sides?
Yes. Bore sizes of 12, 14, 15, and 16 mm can be specified independently for d1 and d2. Any combination within this range is available.
Is the STS7-32 suitable for ATEX-rated installation zones?
316 stainless steel is commonly specified in ATEX Zone 1 and Zone 2 environments due to its low spark risk and corrosion resistance. As a mechanical component, the STS7-32 does not carry an ATEX electrical rating — confirm zone classification requirements with your safety engineer.
Get a Quote for the STS7-32 Stainless Rigid Coupling
Ever Power manufactures the STS7-32 and the complete STS7 stainless series in-house. Material certificates available. Provide bore sizes, quantity, and application for a factory-direct quote.
