Every so often a project lands on the shop floor that shows off exactly what our CNC machining service is built for. This one is a great example: a large-diameter ring gear paired with a precision pinion gear, both machined here at CNC Rapid from 7075 aluminum and finished with Type III hard anodizing.
If you need gearing that is strong, light, and durable — without the weight of steel — this combination is hard to beat.
Why 7075 Aluminum?
7075 is one of the highest-strength aluminum alloys available, with a strength-to-weight ratio that rivals many steels at a fraction of the mass. That makes it a go-to choice for demanding motion and power-transmission components where every gram counts but performance can’t be compromised.
For rotating parts like gears, the payoff is real: lower inertia, faster response, and less load on bearings and supporting structures — all while keeping the assembly rigid and dimensionally stable.
Hardness Where It Matters: Type III Hard Anodizing
Aluminum on its own isn’t the first material people associate with gear teeth — and that’s exactly where the finish earns its keep. Type III (hard) anodizing grows a dense, extremely hard oxide layer directly into the surface of the part.
The result is a component that offers:
- Superior wear resistance on tooth flanks and contact surfaces
- Excellent corrosion protection for harsh or washdown environments
- A low-friction, durable surface that extends service life
- The signature deep bronze/khaki tone you see here — the natural color of a quality hard-anodized finish
It’s the best of both worlds: the light weight of aluminum with a working surface that stands up to real use.
Machined to Perform
These parts are more than good-looking — they’re precise. A few of the details our team dialed in:
- The large ring gear combines fine external gear teeth with a dense pattern of precision-located mounting and lightening holes, all held to tight positional tolerances across a wide diameter of 350 mm.
- The pinion gear features a clean, accurate tooth profile and a keyway for reliable shaft coupling and torque transfer.
- Consistent tooth geometry and flatness across the full face — critical for smooth, quiet meshing and long gear life.
Machining large, relatively thin aluminum discs to this level of accuracy takes proper workholding, sharp tooling, and careful process control to keep everything flat and true. That’s exactly the kind of work the CNC Rapid team specializes in.
Ideal Applications
A ring gear and pinion set like this is a natural fit for precision motion, indexing, and power-transmission systems, including:
- Semiconductor and electronics manufacturing equipment
- Industrial automation and robotics
- Medical and laboratory devices
- Aerospace and defense
- Any application where lightweight, wear-resistant, high-accuracy gearing is a must
Get a Quote on Your Next Project
From one-off prototypes to production runs, CNC Rapid machines precision components in 7075 and other aluminum alloys, engineering plastics, and more — with a full range of finishing options including hard anodizing.
Have a drawing ready? Upload your files to CNC Rapid and we’ll get you a fast, detailed quote.
CNC Rapid is the manufacturing brand of DFM Rapid Limited.
