{"id":763,"date":"2026-06-23T09:46:52","date_gmt":"2026-06-23T09:46:52","guid":{"rendered":"https:\/\/oldhamcoupling.net\/product\/ep6c-25-clamp-type-oldham-coupling\/"},"modified":"2026-06-24T08:47:40","modified_gmt":"2026-06-24T08:47:40","slug":"ep6c-25-clamp-type-oldham-coupling","status":"publish","type":"product","link":"https:\/\/oldhamcoupling.net\/ur\/product\/ep6c-25-clamp-type-oldham-coupling\/","title":{"rendered":"EP6C-25 Clamp Type Oldham Coupling"},"content":{"rendered":"
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EP6C-25 Clamp Type Oldham Coupling \u2014 25 mm Split-Collar Slider for Mid-Range Servo Drives<\/h2>\n

The EP6C-25 clamp Oldham coupling<\/strong> is the mid-range workhorse of the EP6C family. With a 25 mm outside diameter, 38 mm overall length, a six-bore catalogue spanning 6 mm through 12 mm, and a torque envelope of 3.0 N\u00b7m rated \/ 6.0 N\u00b7m peak at 5 800 rpm, it is the natural fit for the 200-W to 400-W servo motor \/ 10\u201312 mm ball-screw drive trains that anchor most laboratory-automation hardware, semiconductor test cells, and benchtop research instruments. Compared to the smaller EP6C-16 and EP6C-20, the EP6C-25 introduces three engineering advantages: substantially higher torsional stiffness (125 N\u00b7m\/rad), wider parallel-misalignment tolerance (1.9 mm), and a broader bore catalogue that covers both metric and imperial shaft standards.<\/p>\n

The architectural value proposition remains the clamp’s: distributed circumferential force on the shaft instead of point loads from a set-screw, no shaft surface marking, full release-and-restore behaviour across hundreds of service cycles, and architectural compatibility with hardened motor shafts. For the laboratory automation use case in particular \u2014 where bench equipment is regularly reconfigured, where dispensing heads are removed for cleaning, and where the shaft surfaces on premium servo motors must be returned in factory condition \u2014 the EP6C-25 is the right specification.<\/p>\n

Specifications<\/h3>\n
\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
\u067e\u06cc\u0631\u0627\u0645\u06cc\u0679\u0631<\/th>\nValue<\/th>\n<\/tr>\n<\/thead>\n
Model<\/td>\nEP6C-25<\/td>\n<\/tr>\n
Outside Diameter (\u03a6D)<\/td>\n25 mm<\/td>\n<\/tr>\n
Overall Length (L)<\/td>\n38 mm<\/td>\n<\/tr>\n
Hub Length (L1)<\/td>\n12.5 mm<\/td>\n<\/tr>\n
Clamp-Gap Width (F)<\/td>\n5.0 mm<\/td>\n<\/tr>\n
Bore-Centre Distance (E)<\/td>\n15 mm<\/td>\n<\/tr>\n
Bore Range (d1 \/ d2)<\/td>\n6, 6.35, 8, 9.525, 10, 12 mm<\/td>\n<\/tr>\n
Rated Torque<\/td>\n3.0 N\u00b7m<\/td>\n<\/tr>\n
Maximum Torque<\/td>\n6.0 N\u00b7m<\/td>\n<\/tr>\n
Maximum Rotational Speed<\/td>\n5 800 rpm<\/td>\n<\/tr>\n
Moment of Inertia<\/td>\n4.1 \u00d7 10\u207b\u2076 kg\u00b7m\u00b2<\/td>\n<\/tr>\n
Static Torsional Stiffness<\/td>\n125 N\u00b7m\/rad<\/td>\n<\/tr>\n
Parallel Misalignment<\/td>\n1.9 mm<\/td>\n<\/tr>\n
\u06a9\u0648\u0646\u06cc\u06cc \u063a\u0644\u0637 \u062a\u0631\u062a\u06cc\u0628<\/td>\n3.0\u00b0<\/td>\n<\/tr>\n
Clamp-Screw Thread<\/td>\nM4<\/td>\n<\/tr>\n
Wrench Tightening Torque<\/td>\n4.0 N\u00b7m<\/td>\n<\/tr>\n
Mass (max bore)<\/td>\n36 g<\/td>\n<\/tr>\n
Backlash<\/td>\n\u0635\u0641\u0631<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

\"EP6C-25<\/p>\n

Materials<\/h3>\n
\n
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Anodised Aluminum Body<\/h4>\n

Both hubs are CNC-machined from A2017-T4 aluminum and clear-anodised. The split-collar gap is wire-EDM finished to a controlled 5.0 mm width with \u00b10.05 mm tolerance \u2014 tighter than competitor specifications and a critical factor in delivering uniform clamping pressure around the shaft. Hard-anodised black variants are offered for lab-equipment OEMs whose product livery dictates a matt-black surface finish.<\/p>\n<\/p><\/div>\n

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High-Performance Slider<\/h4>\n

Standard slider is POM-H homopolymer \u2014 a denser, stiffer grade than the POM-C used in the smaller EP6C sizes. At 3.0 N\u00b7m duty, POM-H delivers superior creep resistance under sustained load. For pharma and biotech applications, a USP-Class-VI compliant PEEK slider variant is documented and available within standard lead times. PTFE-filled POM is offered for chemically aggressive process environments.<\/p>\n<\/p><\/div>\n

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M4 Heavy-Duty Clamp Screws<\/h4>\n

Single M4 socket-head cap screw per hub, SUS304 stainless A2-70. The 4.0 N\u00b7m wrench torque specification develops approximately 2 600 N of clamping force at the split \u2014 sufficient to lock against the 6 N\u00b7m peak torque envelope, while remaining well within the screw’s elastic range for long-term service-cycle endurance.<\/p>\n<\/p><\/div>\n<\/div>\n

Engineering Logic for Lab Automation<\/h3>\n

Laboratory-automation hardware exists in a constant state of low-level reconfiguration. A liquid-handling robot built for one assay protocol may be redeployed for a different protocol next quarter, often with a different dispensing head, a different sample-tray geometry, or a different probe-tip type. Each reconfiguration touches the drive train. The maintenance question \u2014 can the drive coupling survive these repeated touches without accumulating positional error, surface damage, or particle generation \u2014 is exactly the question the clamp-type Oldham architecture is designed to answer.<\/p>\n

The EP6C-25 sits at the size sweet spot for this duty class: large enough to handle the torque needs of typical 200\u2013400 W lab-automation servos, with sufficient parallel-misalignment tolerance (1.9 mm) to forgive the realistic assembly tolerance budget of bench-top frame fabrications, and with a bore catalogue that spans both metric (6, 8, 10, 12 mm) and imperial (6.35, 9.525 mm) shaft standards \u2014 useful when the host equipment mixes Japanese-spec servos with North-American-spec ball-screws. The shaft-friendly clamp engagement supports the multi-thousand reconfiguration cycle profile of typical lab-automation equipment without becoming a maintenance item.<\/p>\n

For background on the broader EP6C family and selection guidance against equivalent Oldham coupling alternatives<\/a>, our technical resources page is the starting point.<\/p>\n

\"EP6C-25<\/p>\n

Industry Applications<\/h3>\n
\n
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<\/span> Liquid-Handling Robots<\/h4>\n

X \/ Y \/ Z-axis servo drives on pipetting robots, dispenser heads, and multi-channel sampling stations. The clamp’s repeat-install behaviour supports the multi-thousand reconfiguration cycle profile typical of high-throughput screening labs.<\/p>\n<\/p><\/div>\n

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<\/span> Microplate Readers & Stackers<\/h4>\n

Carriage and stacker drives in microplate-based assay systems. Repeat-positioning accuracy after coupling service is a primary specification for these machines.<\/p>\n<\/p><\/div>\n

\n

\u269b\ufe0f<\/span> Semiconductor Test Equipment<\/h4>\n

Probe-card alignment and lift-pin drives on wafer-level test handlers. Symmetric clamp force preserves the micrometre-class repeatability that determines test-yield correlation.<\/p>\n<\/p><\/div>\n

\n

<\/span> Cell-Culture Automation<\/h4>\n

Incubator-shaker and bioreactor stirrer auxiliary drives. POM slider isolates the drive motor electrically from the culture vessel, reducing the EMI exposure that can affect sensitive single-cell instruments.<\/p>\n<\/p><\/div>\n

\n

<\/span> Mass-Spectrometry Inlet Drives<\/h4>\n

Auto-sampler injection valves and ion-source positioning stages on LC-MS and GC-MS instruments. Clamp engagement preserves shaft hardness on the precision motor outputs typical of these systems.<\/p>\n<\/p><\/div>\n

\n

<\/span> Diagnostic Centrifuge Drives<\/h4>\n

Rotor-spindle drives on benchtop diagnostic centrifuges. The clamp eliminates the dimple-on-shaft maintenance issue that has historically caused field-service callbacks.<\/p>\n<\/p><\/div>\n<\/div>\n

Why Choose Ever-power<\/h3>\n
\n

Quality & Regulatory<\/h4>\n

EP6C-25 production runs under ISO 9001:2015<\/strong> with full material traceability. Standard documentation pack includes RoHS<\/strong>, REACH<\/strong> SVHC declarations, and conflict-minerals (3TG) status. CE<\/strong> documentation supports machinery-directive integrations. For pharma and biotech customers, USP Class VI<\/strong> material compliance is documented for the PEEK slider variant.<\/p>\n

Customisation<\/h4>\n

Catalogue bores (6, 6.35, 8, 9.525, 10, 12 mm) cover most lab-automation servo and ball-screw shafts. Mixed-bore variants are produced without lead-time penalty. Black hard-anodised hubs, customer logo etching, and tolerance-tightened bores are documented custom-build options.<\/p>\n

Engineering Partnership<\/h4>\n

For OEM lab-automation builders, Ever-power offers a dedicated technical-account-manager assignment with annual volume commitments. Engineering responds within 24 hours<\/strong> in English. CAD files in 12 native formats. Selection guidance and torque-vs-temperature de-rating curves available on request.<\/p>\n<\/div>\n

\"Ever-power<\/p>\n

Customer Reviews & Case Studies<\/h3>\n
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\u2605\u2605\u2605\u2605\u2605<\/p>\n

Chile \u2014 Mining Assay Lab Equipment Builder<\/h4>\n

Used in:<\/em> Servo-drive coupling on XRF sample-changer carousels deployed in remote mining-site labs.<\/p>\n

Feedback:<\/em> “Equipment is field-serviced by site personnel with limited mechanical-engineering background. The clamp’s torque-screw-then-done simplicity has reduced service callbacks substantially compared to our previous set-screw spec \u2014 where over-tightening had been a recurring root cause of slow shaft wear. Documentation pack supports our SAG-mining customer audit requirements without rework.”<\/p>\n<\/p><\/div>\n

\n

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

Greece \u2014 Clinical Diagnostic Manufacturer<\/h4>\n

Used in:<\/em> Centrifuge spindle-drive coupling on a benchtop diagnostic centrifuge family.<\/p>\n

Feedback:<\/em> “The PEEK slider variant we specified for our high-temperature reagent step has now passed 2.5 years of three-shift duty in customer hands without a single warranty replacement. The clamp-type interface is also a positive factor in our medical-device CE documentation \u2014 clean release-and-reinstall is preferable to set-screw marking from a regulatory perspective.”<\/p>\n<\/p><\/div>\n

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

Philippines \u2014 Liquid-Handling Robotics Integrator<\/h4>\n

Used in:<\/em> Pipette-head Z-axis drive on benchtop high-throughput screening robots deployed in research institutions.<\/p>\n

Feedback:<\/em> “Wide bore catalogue (six options) supports our mixed-vendor servo and ball-screw bill of materials without resorting to bushing adapters. Knock one star only because we wish the catalogue extended to 14 mm bore \u2014 the EP6C-32 covers that, but its 32 mm OD is sometimes overkill for our envelope. Engineering team has acknowledged this as a future addition.”<\/p>\n<\/p><\/div>\n<\/div>\n

Frequently Asked Questions<\/h3>\n
\nDoes the EP6C-25 work with mixed metric\/imperial shafts?<\/summary>\n

Yes \u2014 mixed-bore variants such as 9.525 \u00d7 10 mm or 6.35 \u00d7 8 mm are standard production. The clamp engagement does not change with shaft material or thread profile, so a metric servo can be coupled to an imperial ball-screw without bushing or adapter.<\/p>\n<\/details>\n

\nWhat is the cleanroom particle generation profile?<\/summary>\n

The clamp engagement is non-shedding \u2014 no metal swarf is produced during install or removal. Anodised surfaces are particulate-stable. The EP6C-25 has been validated for Class 7 cleanroom service in customer applications; for Class 5 and below, supplementary documentation can be supplied on request.<\/p>\n<\/details>\n

\nHow does the EP6C-25 perform at extended temperature?<\/summary>\n

Catalogue specification is for the \u221240 \u00b0C to +100 \u00b0C continuous operating range. The PEEK slider variant extends the upper bound to +260 \u00b0C. Below \u221240 \u00b0C, the aluminum hub’s coefficient of thermal contraction may reduce clamp force; for cryogenic applications please consult engineering for a custom-toleranced variant.<\/p>\n<\/details>\n

\nCan the EP6C-25 carry an OEM private label?<\/summary>\n

Yes. Laser-etched OEM labels are an established custom-build option with documented quality controls. Minimum order quantity for private labelling is 100 pieces. Specify the etch pattern and approximate location on the hub face at order entry.<\/p>\n<\/details>\n

\nIs the EP6C-25 included in your Kanban or VMI programmes?<\/summary>\n

Yes \u2014 the EP6C-25 is a high-volume catalogue line and supports both customer-specific Kanban and vendor-managed-inventory (VMI) programmes. Buffer stock can be held at Ever-power’s facility for JIT replenishment, or staged at a customer-nominated 3PL warehouse. Please contact sales for programme terms.<\/p>\n<\/details>\n

Specify the EP6C-25 for Lab Automation<\/h3>\n

For laboratory automation, semiconductor test, and diagnostic instrument OEMs, the EP6C-25 is one of Ever-power’s most-specified mid-range clamp Oldham couplings. Explore the full coupling catalogue<\/a>, read about our OEM partnership programmes<\/a>, or proceed to enquiry below.<\/p>\n

\n Quote EP6C-25 \u2192<\/a>\n<\/p>\n