A technical overview of the three principal face couplings (Hirth, Coniflex, and Curvic), comparing their tooth geometries, self-centering behavior, and Gleason’s cutting and grinding processes for manufacturing them.




This paper presents a new analytical method using plate and disk mechanical models to calculate the gear body stiffness of face gear wheels, showing that stiffness decreases toward the outer radius—a behavior that conventional cylindrical gear approaches fail to capture.
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This excerpt from Gear Technology Solutions explains how oversized cutter blade edge radii cause root interference in bevel gears, and how to select correct radii to avoid noise, flank damage, and tooth fracture.
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Water spray quenching achieves heat transfer coefficients up to 4,000 W/(m²K)—nearly double conventional oil quenching rates—enabling potential material substitution and tailored quench intensity for complex gear components.
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20NiMo9-7 alloy achieves up to 48 percent higher fatigue strength than conventional carburizing steels in the as-carburized condition, eliminating the need for shot peening and grinding in automotive gear applications.
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The conjugacy of meshing gears is one of the most important attributes of gears because it ensures a constant velocity ratio that gives smooth, uniform transmission of motion and torque. Some of the world’s greatest gear theoreticians like Earle Buckingham, Wells Coleman, and John Colbourne laid the foundation for understanding conjugacy. Their teachings and interpretations of the law of gearing have been used by generations of gear engineers to design and manufacture gear transmissions for almost everything that is mechanically actuated.

The arrival of Gleason’s Hard Finishing Cell (HFC) in 2018 represented a paradigm shift in the way automotive transmission gears and gears for e-drives, could be produced in high volumes. Now, for the first time, 100 percent inspection of every gear, and every gear tooth was possible in-process, without impacting the high speeds at which these gears need to be hard finished. Identifying, and correcting for, conditions that create unacceptable noise behavior in these gears, on the fly, was finally a reality too.

Furnaces North America 2022 (FNA 2022), presented by the Metal Treating Institute (MTI), in partnership with its media partner, Heat Treat Today, is the heat-treating industry’s go-to event every other year. FNA 2022 attracted attendees from across North America, including Fortune 500 companies. For three days attendees took part in networking, connections, and learning about the vast changes taking place in emerging technologies, industry trends, and advances in equipment.
The demand for double helical gears in planetary gear systems for engines in the civil aerospace industry is increasing. Innovative grinding processes and state-of-the-art technologies ensure precision, reduced weight, and improved cost efficiency. Learn how KAPP NILES reduced the gap width from 30 mm to 15 mm.
Discover four diagnostic enhancement tools that move RX® endothermic gas atmosphere generator operations from preventative to predictive maintenance. Learn how monitoring dew point by retort, comparing equal flow, tracking tube performance, and measuring outlet temperatures prevent costly failures while ensuring consistent, high-quality carrier gas production.
The right hob can make a measurable difference in gear production. Watch the video to see how Star SU combines advanced hob technology with application expertise to help manufacturers get more from every gear cutting operation.
The Intra SFTX twin-spindle single-flank testing system is engineered for advanced gear quality testing and NVH analysis of demanding e-drive gear applications. Combining Transmission Error (TE) and Torsional Acceleration (TA) measurements, it delivers fast, precise diagnostics and detailed order analysis, quickly identifies critical gear issues, enhances traceability, and helps prevent costly defects from reaching end-of-line (EOL) testing.
The 80PS Power Skiving and Hobbing Machine is specifically engineered for power skiving, hobbing, and profile milling of small internal and external gears. Configured specifically for the demands of humanoid robotic gear production, it delivers outstanding performance and process stability for gears used in strain wave, planetary, and cycloidal gearboxes, as well as other high-precision applications of comparable size — even when machining fine-pitch gears and thin-walled components.
At Gear Headquarters, quality is the foundation of everything they do. Based in Kansas City, the shop manufactures spur, helical, double-helical, herringbone, bevel, internal, spline, and worm gears, sprockets, and timing belt pulleys.

Kennametal Inc. announced it will bring the modern manufacturing ecosystem to life at IMTS 2026 with the Next Level Shop, an immersive experience featuring appearances of WIDIA brand ambassador Carey Hart, a live custom motorcycle build, and the latest machining and digital manufacturing technologies designed to help manufacturers improve productivity.
Dec 8, 2026 - Dec 9, 2026

CTI Symposium Berlin offers active discussions on the latest technologies and strategies on automotive transmissions and HEV & EV drives for passenger cars and commercial vehicles. At CTI Symposium Berlin, more than 650 senior experts and decisionmakers from OEMs, Tier 1 suppliers, technology companies, and research institutions come together to discuss the latest developments in electrified drivetrains, hybrid technologies, energy systems, software integration, and future mobility strategies.
Sep 22, 2026 - Sep 23, 2026
Oct 12, 2026 - Oct 14, 2026
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