Custom Aluminum Alloy Jaw Coupling
Zero-backlash · Lightweight · Application-ready - built for servo, semiconductor, medical & packaging automation
6061-T6 / 7075-T6
H7 bore · DIN 6885 keyway
Zero-backlash curved jaw option
ISO 9001:2015 system
DIN 740 reference
types of CNC machining
Most jaw couplings on the market are sold as unfinished hubs. You machine the bore yourself, source the spider separately, and absorb the risk of tolerance stack-up. We supply application-ready aluminum jaw coupling assemblies - hubs machined to your bore, keyway, and clamp configuration, paired with the correct spider durometer, inspected and shipped as one traceable unit.
What that means on your floor:
- No secondary machining - H7 bore and keyway cut to your drawing, not left as a pilot bore.
- Zero-backlash option - curved-jaw geometry press-fits the spider for constant velocity in servo positioning, where standard straight-jaw couplings introduce lost motion.
- Fail-safe by design - if the elastomeric spider wears, the jaws still interlock and transmit torque until scheduled replacement, avoiding sudden line-down events.
- Lightweight, low inertia - 6061-T6 or 7075-T6 aluminum hubs reduce reflected inertia on high-acceleration servo axes without sacrificing torque density.
Material & Finish - Specified, Not "Aluminum"
| Parameter | Standard | Optional / Upgraded | Engineering note |
| Hub material | 6061-T6 | 7075-T6 | 7075-T6 offers higher torsional rigidity and strength; specified for high-precision, high-rigidity axes |
| Hardness (reference) | 6061: ~95 HB | 7075: ~150 HB | Higher hardness resists jaw wear under repeated start/stop |
| Surface finish | Clear anodized | Hard anodized ≥50 μm; black anodized; sandblast | Hard anodizing recommended for high-wear, high-cycle applications |
| Bore tolerance | H7 | Custom tolerance on request | H7 fit minimizes clearance, preserves concentricity |
| Keyway | DIN 6885 / JS9 | Custom | Standard for North American and European shaft interfaces |
| Axial runout | < 0.02 mm | Dynamic balancing available | For smooth high-RPM rotation |
| General tolerances | ISO 2768-mK | ISO 2768-fH | fH recommended for precision rotation |
Spider Selection - Match the Element to the Duty
The aluminum hubs are only half the specification. Spider durometer and material determine torque capacity, damping, temperature range, and misalignment accommodation. Use the table below to select the right element for your application; we will supply the matched spider with every assembly.
| Spider material | Temperature range | Torque character | Damping | Best for |
| NBR (rubber) | −40°C to +100°C | Standard | High | General industrial, pumps, fans, conveyors - most economical |
| Polyurethane | −34°C to +71°C | ~1.5× NBR torque | Low | Higher torque density; not ideal for cyclic start/stop |
| Hytrel | −51°C to +121°C | High torque / high temp | Low | High-torque, elevated-temperature duty; not for cyclic start/stop |
Selection rule for servo/automation: if the axis requires precise positioning under repeated starts and stops, specify a curved-jaw zero-backlash hub + 98 Shore A spider; if the duty is continuous torque transmission with vibration damping, a standard straight-jaw + 85 Shore A NBR spider is the lower-cost correct choice.
Application Fit - Where This Coupling Belongs
Aluminum jaw couplings are not a universal answer. They earn their place in applications where lightweight, corrosion resistance, zero-backlash, and damping matter more than raw torque density. The table below is the application matrix we use in quoting; if your application sits outside it, tell us and we will say so.
| Industry / application | Why aluminum jaw coupling fits | Specification emphasis |
| Semiconductor / solar | Zero-backlash, low particle generation, balanced design for constant velocity | 7075-T6, hard anodize, curved jaw, dynamic balance |
| Medical / surgical robotics | Damping reduces settling time and shock loads; lightweight reduces distal inertia | 6061-T6 or 7075-T6, tight runout, clean finish |
| Packaging automation | Accommodates misalignment, fail-safe operation, visual inspection without disassembly | NBR or urethane spider, clamp-style hubs |
| Servo / stepper positioning | Zero-backlash curved-jaw geometry; constant velocity under demanding start/stop | Curved jaw, 98 Shore A, H7 bore |
| Food processing / conveyors | Corrosion-resistant aluminum, no lubrication, easy washdown-compatible finish | Anodized 6061-T6, NBR spider |
Customization - What We Actually Need From You
"Custom" is meaningless without a defined boundary. This is the customization envelope for this product line:
| Customization | Available range / option | What to send |
| Hub material | 6061-T6 / 7075-T6 | Material callout on drawing |
| Bore diameter | Per drawing; H7 standard | Bore diameter + tolerance |
| Bore configuration | Straight, stepped, tapered bod | 2D drawing with axial dimensions |
| Keyway | DIN 6885 / JS9, or per drawing | Keyway width × depth |
| Fastening | Clamp style, set screw style | Preferred fastening method |
| Surface finish | Clear / black / hard anodize; sandblast | Finish spec and masking areas |
| Spider | NBR / urethane / Hytrel; 85A–98A | Torque, RPM, temperature, duty cycle |
| Marking / packaging | Laser marking, individual bag + label | Marking content, packaging requirement |
| Traceability | Material cert, dimensional report, PPAP on request | Required documentation level |
What we do not do: we do not reverse-engineer a competitor's part number and ship an unverified "equivalent." If you send a sample or a brand/model reference, we will confirm geometry and material equivalence in writing before quoting.
Quality & Compliance - The Part North American Buyers Check First
For MRO and OEM procurement in North America, a jaw coupling without documented compliance is a line-down risk, not a cost saving. This product is manufactured and inspected under the following framework:
- ISO 9001:2015 quality management system - covering raw material sourcing through final inspection and packaging.
- DIN 740 dimensional and performance reference for flexible jaw couplings.
- Bore tolerance H7; keyway DIN 6885 / JS9 - the fit language used by North American and European shaft standards.
- Material traceability - aluminum bar stock from certified mills; material certificate available with every lot.
- Inspection report - dimensional report (bore, runout, keyway, jaw profile) supplied on request; PPAP documentation available for OEM programs.
If your receiving inspection requires a specific standard or document set, state it at RFQ. We will confirm in writing before the PO, not after.
Ordering Logic - How to Configure a Complete Assembly
A jaw coupling is a three-piece assembly: two hubs + one spider. A common sourcing error is ordering "a coupling" and receiving only one hub. Use this configuration sequence:
- Torque & RPM → determines hub size and spider durometer.
- Shaft diameters (both sides) → determines bore sizes and whether a stepped bore is needed.
- Misalignment → angular, parallel, axial; determines spider hardness and jaw profile (straight vs. curved).
- Environment → temperature, chemicals, washdown; determines spider material and hub finish.
- Fastening → clamp vs. set screw; clamp is preferred for zero-backlash and easier field replacement.
- Documentation → material cert, dimensional report, PPAP, or marking requirements.
Send items 1–5 in a single RFQ and we will return a configured part number, drawing, and firm lead time - not a request for more information.
Contact
Send us: 2D drawing (PDF / DWG / STEP) + shaft diameters + torque / RPM + ambient temperature + spider preference (or duty description) + required documentation.
You will receive within 24 business hours: manufacturability review, material recommendation (6061 vs. 7075, finish, spider), firm unit price at your quantity, and lead time from PO.
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