Description
STS7C-20 Stainless Steel Clamp Type Rigid Coupling – 20mm OD 316SS Corrosion-Resistant Split-Body Connector
The STS7C-20 clamp type rigid coupling is the 316 stainless steel version of the TS7C-20 aluminum alloy model. It retains the split-body clamp mechanism, bore range of 6, 8, rated torque of 0.5 N·m, and maximum speed of 5,400 rpm of the aluminum variant — the only change is the body material, which is machined from 316 austenitic stainless steel rather than aluminum alloy. The STS7C-20 weighs 40 g (compared to 14.5 g for the TS7C-20) and delivers the same non-marring, zero-backlash, repositionable shaft connection in environments where aluminum would corrode.
At 40 g (versus 14.5 g for the TS7C-20 aluminum version), the STS7C-20 introduces the expected mass penalty of 316SS material but loses nothing in bore range, torque rating, or clamp mechanism functionality. The M3 clamp screws and 9 mm hub length are unchanged from the aluminum model.
The stainless clamp mechanism is particularly valuable in food processing and pharmaceutical applications where the non-marring connection advantage of the clamp design and the corrosion resistance of 316SS are both required simultaneously — a combination that neither the aluminum clamp nor the stainless setscrew model addresses alone. Material certificates confirming 316SS grade are available on request. Full series listings are on our product catalog page.
Technical Specifications
| Parameter | Value |
|---|---|
| Model | STS7C-20 |
| Body Material | 316 Stainless Steel |
| Outer Diameter (D) | 20 mm |
| Overall Length (L) | 30 mm |
| Hub Length (L1) | 9 mm |
| Available Bore Sizes | 6, 8 |
| Clamp Screw Thread | M3 |
| Rated Torque | 0.5 N·m |
| Maximum Torque | 1 N·m |
| Maximum Rotational Speed | 5,400 rpm |
| Moment of Inertia | 2.3 × 10⁻⁶ kg·m² |
| Mass | 40 g |
Dimension Drawing
Stainless Steel Clamp Coupling — Dual Advantage
The STS7C-20 addresses two requirements simultaneously that no single alternative coupling design can match: (1) a non-marring, distributed-clamp shaft connection that protects precision shaft surfaces and allows repositioning during commissioning, and (2) a 316 stainless steel body that resists corrosion in food washdown, pharmaceutical, and wet industrial environments. Applications in these sectors often require both attributes — a stainless setscrew would still mark the shaft surface, while an aluminum clamp coupling would corrode in the operating environment. The STS7C-20 solves both constraints in a single component.
The 316 stainless steel alloy used in the STS7C-20 contains molybdenum (2–3%), which provides improved chloride pitting resistance compared to the more common 304 grade. This is specifically valuable in environments with sodium hypochlorite (bleach), chlorinated CIP solutions, sea water, and chloride-containing industrial chemical atmospheres where 304 stainless would develop pitting over time.
Typical Applications
- Beverage filling machine encoder shaft connections — wet zone with chlorinated CIP, non-marring clamp required by encoder manufacturer
- Dairy processing conveyor servo drives — washdown environment with precision ground encoder shaft
- Pharmaceutical tablet press encoder feedback — solvent-atmosphere GMP zone, stainless required
- Chemical laboratory autosampler positioning drives — solvent splash and corrosive vapour environment
- Coastal industrial HVAC damper actuator feedback — salt-laden humid atmosphere with precision shaft surface requirement
Customer Reviews and Case Studies
★★★★★
Netherlands — Dairy Equipment OEM
We manufacture automated dairy filling machines and the STS7C-20 is our standard encoder coupling for servo drives in the filling and CIP zone. The combination of 316SS body and non-marring clamp is exactly what we need — previous aluminum setscrew couplings failed on both counts within months of installation in this environment.
— Design Engineer, Eindhoven
★★★★★
Belgium — Pharmaceutical Packaging
Installed in tablet press encoder connections in a solvent-atmosphere GMP room. The 316SS material satisfied our material specification for the zone, and the clamp connection preserved the encoder shaft surface through multiple encoder replacements. Material certificates were supplied with first delivery.
— Validation Engineer, Liège
★★★★☆
New Zealand — Food Processing
Used in a fish processing conveyor servo encoder connection — one of the harshest wash-down environments in our facility. The STS7C-20 has remained free of corrosion for 14 months of daily bleach washdown. The 6/8 mm bore matched our servo motor and encoder shafts directly.
— Maintenance Engineer, Christchurch
Frequently Asked Questions
What distinguishes the STS7C-20 from all three alternatives?
Compared to the TS7C-20 (aluminum clamp): same mechanism, stainless body. Compared to the STS7-20 (stainless setscrew): same material, non-marring clamp instead of point-contact setscrew. Compared to the TS7-20 (aluminum setscrew): both material and mechanism differ. The STS7C-20 is the only model combining both 316SS material and non-marring clamp.
What bore combinations are available for the STS7C-20?
6 and 8 mm bore diameters on each side independently. Equal-bore (6/6 or 8/8) and mixed-bore (6/8) configurations are available.
Does the STS7C-20 match the dimensions of the TS7C-20?
Yes. All external and internal dimensions are identical between STS7C-20 and TS7C-20. It is a direct material-substitution replacement.
Is the STS7C-20 suitable for steam cleaning?
316 stainless steel maintains its properties through steam cleaning cycles at temperatures up to approximately 150°C — the typical range for food and pharmaceutical steam clean protocols.
Can material traceability be provided for the STS7C-20?
Yes. 316SS mill certificates with heat number and composition data are available on request, supporting GMP, food safety, and regulatory procurement file requirements.
Enquire About the STS7C-20 Stainless Clamp Rigid Coupling
Ever Power manufactures the STS7C-20 and the complete STS7C stainless clamp coupling series in-house, with 316SS material certification on request. Provide bore sizes, quantity, and application details for a factory-direct quote.
