Description
EP6-70 Heavy Industrial Set Screw Oldham Coupling — 70 mm Three-Piece Slider for High-Power Drive Trains
The EP6-70 Oldham coupling is the largest set-screw variant in the EP6 family — and a watershed point in the catalogue. With a 70 mm outside diameter, 59 mm overall length, six catalogue bores spanning 24 mm through 35 mm, and a torque envelope of 80 N·m rated / 160 N·m peak at 2 300 rpm, the EP6-70 transmits up to 19 kW of continuous mechanical power. At this scale the coupling no longer serves benchtop instruments or light-automation gantries; it becomes the flexible connector between substantial gearmotors and the kind of heavy industrial driven loads where unplanned downtime carries hard-dollar consequences.
Selection rationale at this size focuses on three engineering priorities: torque density (more torque per kilogram of reflected inertia than a steel-disc-pack coupling of equivalent rating), misalignment forgiveness (the EP6-70’s 3.8 mm allowance compares favourably to under-1 mm for typical metallic-disc options), and serviceability (slider replacement remains a sub-shift operation regardless of how the coupling has been installed). The combination is what convinces fleet engineers to specify the EP6-70 across compressor packages, conveyor head-pulley drives, large mixer trains, and crane auxiliary lines.
Specifications
| Parameter | Value |
|---|---|
| Model | EP6-70 |
| Outside Diameter (ΦD) | 70 mm |
| Overall Length (L) | 59 mm |
| Bore Range (d1 / d2) | 24, 25, 28, 30, 32, 35 mm |
| Rated Torque | 80 N·m |
| Maximum Torque | 160 N·m |
| Maximum Rotational Speed | 2 300 rpm |
| Moment of Inertia | 1.7 × 10⁻⁴ kg·m² |
| Static Torsional Stiffness | 1 600 N·m/rad |
| Parallel Misalignment | 3.8 mm |
| Angular Misalignment | 3.0° |
| Set-screw Thread | M10 |
| Wrench Tightening Torque | 32 N·m |
| Mass (max bore) | 456 g |
| Backlash | Zero |
Materials
Heavy-Section Aluminum Hubs
Hubs are machined from A6061-T651 stress-relieved aluminum bar and hard-anodised with a 60 µm wear-resistant coating. The heavier-section design distributes the M10 set-screw clamping force over a larger thread engagement, eliminating the bore-distortion risk that smaller hubs can exhibit when set screws are over-torqued.
Industrial-Grade Slider
At the EP6-70’s duty class, the standard slider is 25 % glass-fibre-reinforced POM-H — a step up from the 15 % GF-POM used in smaller EP6 sizes. The higher filler loading raises continuous-service torque capacity at elevated temperature and improves creep resistance under sustained load. PEEK is available for >110 °C continuous service; stainless-steel hub variants are released for marine and food-handling deployments.
Heavy M10 Set-Screw Pairs
Two M10 SUS304 cup-point set screws per hub, separated by 90°. Specified at 32 N·m wrench torque. The cup-point geometry produces a measurable depression in the shaft surface at first tightening — for high-cycle reversible duty, dimpled-key flats are recommended to provide a positive shaft engagement that does not migrate over time.
Selecting the EP6-70 at the High-Power Limit
At 80 N·m / 2 300 rpm — roughly 19 kW continuous — the EP6-70 sits at a selection junction where alternatives such as steel disc-pack couplings, grid couplings, and double-flex shaft couplings become realistic competitors. The reasons engineers continue to choose the EP6-70 in this competitive space come down to four practical factors. First, installation: there is no disc-pack timing, no machined ground key, no precision shimming — just two shafts, two hubs, four set screws, and a centre disc. Total install time for a trained technician is under 15 minutes.
Second, inertia: at 1.7 × 10⁻⁴ kg·m², the EP6-70’s reflected inertia at the motor is roughly half that of a comparable steel-disc-pack coupling, reducing the work that the host servo or VFD-controlled motor has to do during acceleration and braking events. Third, misalignment tolerance: the 3.8 mm parallel-offset envelope removes the need for precision laser-aligned shaft mounting, which can save days during commissioning of a new production line. Fourth, replaceability: a worn slider can be exchanged in the field with hand tools and a 10-minute downtime window — a service interval that simply cannot be matched by any flexible-disc or grid coupling.
Industry Applications
Industrial Compressor Packages
Motor-to-compressor connection on screw and scroll air compressors up to 22 kW. The slider’s misalignment tolerance absorbs the substantial thermal growth between motor and compressor heads during start-up.
Conveyor Head Pulley Drives
Drive-end couplings on heavy belt and apron conveyors. Slider absorbs the shock load when material loading is uneven or when emergency-stop arrest is triggered.
️ Crane Auxiliary Drives
Trolley traverse, hoist auxiliary, and outrigger drives on overhead bridge and gantry cranes. The EP6-70 is a maintenance-engineer favourite for its serviceable wear part.
Heavy Mixer Reduction Output
Coupling between worm-gear or planetary-reduction output stage and large blender, mixer, or kneader impeller shaft. Forgives thermal growth that occurs between cold-process and operating temperature.
Wastewater Treatment Pumps
Large centrifugal and lobe-pump drives in municipal and industrial wastewater plants. Polymer slider provides electrical isolation between motor frame and wet-end pump body.
⚒️ Steel-Mill Auxiliary Trains
Roll-table, finishing-mill, and coiler auxiliary drive lines. High-temperature PEEK slider variant survives the elevated ambient typical of these mill sections.
Why Choose Ever-power for the EP6-70
Quality Documentation
EP6-70 production runs under an ISO 9001:2015 management system, with full material and dimensional traceability. RoHS and REACH conformity declarations are standard. CE documentation supports machinery-directive integrations across the EU. For oil-and-gas applications, supplementary NACE MR0175 material compatibility statements can be issued for stainless-hub variants.
Customisation
Beyond the catalogue bore set (24 / 25 / 28 / 30 / 32 / 35 mm), Ever-power produces custom bores up to 40 mm, asymmetric bore pairings (e.g., 25 × 32 mm), keyway-broached bores to DIN/JIS, stainless-steel hub variants, and PEEK slider upgrades. Logo-marking and OEM private labelling are available with documented quality controls.
Production & Support
Monthly EP6-70 capacity exceeds 5 000 pieces across the bore matrix. For project-driven OEMs and fleet operators, Ever-power maintains buffer stock at customer-specific levels. Application engineers respond within 24 hours. Sea, air, and land freight are all supported globally; for plant-shutdown emergencies, expedited air freight is available within 48 hours of confirmed PO.
Customer Reviews & Case Studies
★★★★★
Thailand — Air Compressor Package Builder
Used in: Direct-drive connection between 18.5 kW motor and twin-screw compressor head on stationary plant packages.
Feedback: “Thermal growth between motor and head can reach 2 mm during start-up. The EP6-70’s 3.8 mm allowance handles this without imposing any radial side-load on the screw rotor bearings. We have standardised on the EP6-70 across our 15–22 kW package range and seen warranty claims for compressor-bearing failures drop to near-zero.”
★★★★★
South Africa — Mining Conveyor Operator
Used in: Drive-end coupling on a 90 m underground belt conveyor moving copper ore.
Feedback: “Conveyor experiences intermittent shock loads from large rock-fall events. The EP6-70 polymer slider absorbs these shocks where our previous fluid coupling required hour-long restarts. Slider-replacement service interval is now scheduled at 18 months — minimal downtime, easy parts availability.”
★★★★☆
Israel — Industrial Mixer Builder
Used in: Reduction-output to impeller-shaft coupling on 15 kW class chemical mixers.
Feedback: “Replaced our previous chain-coupling specification, which had been failing prematurely under reactive-chemistry exposure. The PEEK slider variant we now use has been in service 14 months with no measurable wear. Knock one star only because we want a metric/imperial mixed-bore catalogue option to cover US-shaft customers without custom lead time.”
Frequently Asked Questions
What is the maximum continuous-duty power the EP6-70 can transmit?
At 2 300 rpm and rated 80 N·m, the EP6-70 transmits 19.3 kW continuously. Power capacity scales linearly with operating speed; at 1 500 rpm the continuous rating is approximately 12.5 kW. For sustained operation above 19 kW, please consult engineering for a stress-life evaluation.
How does the EP6-70 compare to a steel-disc-pack coupling of similar rating?
Steel-disc-pack couplings at this torque rating offer marginally higher peak-torque endurance (typically 200 N·m peak) and lower mass (450 g vs ~600 g for a comparable steel coupling). The EP6-70 offsets these with a 4× wider misalignment envelope, dramatically simpler installation, and an order of magnitude lower service cost over a 10-year lifecycle.
Can the EP6-70 be installed on key-locked shafts?
Yes — keyway broaching to DIN 6885 or JIS B 1301 standards is a routine custom-build option. Specify the keyway dimensions at order entry. Lead time addition is typically 5–7 working days. The combination of keyway and set-screw provides positive shaft engagement that does not migrate even under high-cycle reversal duty.
What is the expected service life under typical industrial duty?
For an EP6-70 operating at 60 % of rated load, with parallel offset below 2 mm and ambient under +70 °C, expected slider life exceeds 7 years of continuous duty. Slider-only replacement at end-of-life restores the coupling to as-new performance and takes typically 15 minutes including documentation.
Is on-site engineering support available for plant-scale specifications?
For fleet-scale projects and plant-wide specifications, Ever-power’s engineering desk can support remote engineering reviews via video conference. On-site visits can be arranged for projects with 1 000+ piece annual commitments; please contact the sales desk to discuss programme terms.
Specify the EP6-70 for Heavy-Duty Builds
For heavy industrial drive trains across compressor, conveyor, mixer, crane, and process applications, the EP6-70 delivers the rare combination of torque density, misalignment forgiveness, and field-serviceability that fleet engineers prize. Browse our complete heavy-duty Oldham coupling catalogue, read about Ever-power’s industrial production capability, or proceed directly to a quote enquiry below.