{"id":3475,"date":"2026-07-08T05:14:34","date_gmt":"2026-07-08T05:14:34","guid":{"rendered":"https:\/\/rigid-shaft-coupling.top\/product\/sts7-40-stainless-steel-setscrew-rigid-coupling-40mm-od-316ss-heavy-duty-corrosion-resistant-coupler\/"},"modified":"2026-07-08T05:14:35","modified_gmt":"2026-07-08T05:14:35","slug":"sts7-40-stainless-steel-setscrew-rigid-coupling-40mm-od-316ss-heavy-duty-corrosion-resistant-coupler","status":"publish","type":"product","link":"https:\/\/rigid-shaft-coupling.top\/it\/product\/sts7-40-stainless-steel-setscrew-rigid-coupling-40mm-od-316ss-heavy-duty-corrosion-resistant-coupler\/","title":{"rendered":"STS7-40 Stainless Steel Setscrew Rigid Coupling \u2013 40mm OD 316SS Heavy-Duty Corrosion-Resistant Coupler"},"content":{"rendered":"
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STS7-40 Stainless Steel Setscrew Rigid Coupling \u2013 40 mm OD 316SS Heavy-Duty Corrosion-Resistant Coupler<\/h1>\n

The STS7-40<\/strong> is the largest and highest-torque model in the STS7 stainless steel series, delivering 5 N\u00b7m rated torque at up to 8,000 rpm through a 40 mm outer diameter 316 stainless steel body. With bore options from 14 to 20 mm, it serves large-frame servo motor and gearhead output connections in environments where the highest level of corrosion resistance in the TS7\/STS7 family is required. The M5 setscrew thread and 1.7 N\u00b7m wrench torque are the same as the TS7-40 aluminum equivalent. All torque, speed, and geometric specifications are identical between the two material variants.<\/p>\n

The STS7-40 weighs 210 g \u2014 2.1 times the 100 g TS7-40 \u2014 and the moment of inertia is 2.4 \u00d7 10\u207b\u2076 kg\u00b7m\u00b2. For servo axis inertia calculations in the motor power range this coupling serves (typically 750 W to 2 kW), the additional coupling inertia remains small relative to load-side inertia and within normal servo stability limits. For very high-acceleration, low-load applications, include this figure in the servo amplifier inertia ratio check.<\/p>\n

Material traceability certificates are available with every order on request \u2014 a standard requirement for offshore, food safety, and pharmaceutical procurement. The full STS7 stainless coupling range is detailed on our product catalog page<\/a>.<\/p>\n

Technical Specifications<\/h2>\n
\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Parameter<\/th>\nValue<\/th>\n<\/tr>\n<\/thead>\n
Model<\/td>\nSTS7-40<\/td>\n<\/tr>\n
Body Material<\/td>\n316 Stainless Steel<\/td>\n<\/tr>\n
Outer Diameter (D)<\/td>\n40 mm<\/td>\n<\/tr>\n
Overall Length (L)<\/td>\n50 mm<\/td>\n<\/tr>\n
Hub Length (L1)<\/td>\n12 mm<\/td>\n<\/tr>\n
Available Bore Sizes<\/td>\n14, 16, 18, 19, 20 mm<\/td>\n<\/tr>\n
Setscrew Thread<\/td>\nM5<\/td>\n<\/tr>\n
Wrench Torque<\/td>\n1.7 N\u00b7m<\/td>\n<\/tr>\n
Rated Torque<\/td>\n5 N\u00b7m<\/td>\n<\/tr>\n
Maximum Torque<\/td>\n10 N\u00b7m<\/td>\n<\/tr>\n
Maximum Rotational Speed<\/td>\n8,000 rpm<\/td>\n<\/tr>\n
Moment of Inertia<\/td>\n2.4 \u00d7 10\u207b\u2076 kg\u00b7m\u00b2<\/td>\n<\/tr>\n
Mass<\/td>\n210 g<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Dimension Drawing<\/h2>\n

\"STS7-40<\/p>\n

Why the STS7-40 in Demanding Environments<\/h2>\n

The STS7-40 occupies the intersection of high torque capacity and maximum corrosion resistance within the TS7\/STS7 product family. At 5 N\u00b7m rated torque, it serves drive axes that are beyond the capacity of smaller precision couplings; the 316 stainless body extends this performance into environments \u2014 meat processing, fish handling, chemical reactors, offshore platforms, desalination plants \u2014 where the daily operating environment would degrade an aluminum coupling within weeks. The STS7-40 is not simply a corrosion-resistant upgrade: it is the correct engineering choice for applications that combine high torque demand with environmental aggression. A shaft flat on both shaft ends is recommended at this frame size for all torque levels near or above the rated 5 N\u00b7m.<\/p>\n

Typical Applications<\/h2>\n
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  • Large servo encoder connections on stainless washdown conveyors<\/strong> in meat and fish processing plants<\/li>\n
  • Chemical reactor agitator position feedback drives<\/strong> in solvent and acid atmosphere zones<\/li>\n
  • Offshore platform instrument and valve actuator drives<\/strong> in salt-spray, high-humidity environments<\/li>\n
  • Pharmaceutical lyophiliser door drive encoder connections<\/strong> in CIP-qualified environments<\/li>\n
  • Desalination plant actuator feedback shafts<\/strong> with continuous brine-spray exposure<\/li>\n<\/ul>\n

    Customer Reviews and Case Studies<\/h2>\n
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    \n

    \u2605\u2605\u2605\u2605\u2605<\/p>\n

    United Kingdom \u2014 Meat Processing Equipment<\/p>\n

    We manufacture stainless washdown conveyor systems for beef processing plants and the STS7-40 is our standard servo encoder coupling for the largest drive axes. The 20 mm bore matches our motor output shaft, and the 316SS body survives daily chlorine washdown without a mark. In use for over two years.<\/p>\n

    \u2014 Design Engineer, Leeds<\/p>\n<\/div>\n

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    \u2605\u2605\u2605\u2605\u2605<\/p>\n

    Spain \u2014 Chemical Process Plant<\/p>\n

    Installed on servo-driven chemical dosing pump encoder connections in a concentrated HNO3 vapour zone. 316SS was the only material acceptable to our process safety team. Performing correctly for 16 months with no corrosion or mechanical issues.<\/p>\n

    \u2014 Process Engineer, Tarragona<\/p>\n<\/div>\n

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    \u2605\u2605\u2605\u2605\u2606<\/p>\n

    UAE \u2014 Desalination Plant Operator<\/p>\n

    Replacement couplings for valve actuator position encoders in our brine pump hall \u2014 one of the harshest salt-corrosion environments possible. The STS7-40 has maintained its condition over 12 months where stainless was the absolute minimum material requirement.<\/p>\n

    \u2014 Instrumentation Engineer, Abu Dhabi<\/p>\n<\/div>\n<\/div>\n

    Frequently Asked Questions<\/h2>\n