Large Scale Gear Manufacturing for a Mining Application

At Industrial Sprockets & Gears, Inc. , we are able to manufacture premium quality gears with unusually large sizes and unique diametral pitch values. The gear featured here is two-piece kiln drive gear with a reversible design that allows the customer to double the life of the gear. The customer contacted us regarding this project as a result of our reputation for machining large gears to tight tolerances.

The large gear is made of 4140 normalized and tempered steel. It was machined on a CNC Gould & Eberhard gasher and gear hobbing machine that is capable of accommodating gears up to 30’ in diameter. The dimensions of the gear include an outer diameter of 181.33″, a 14″ gear face, and a diametral pitch of .75 or 3/4. We are one of the few custom gear machining shops that specializes in gears with a .75 normal diametral pitch. The gear was machined to AGMA Class 10 tolerances, which include dimensional tolerances as tight as ±0.002″.

When finished, the gear weighed 7 tons, making it quite a challenge to transport to the heat treating facility in one piece. Upon delivery, the customer remarked that the finish on the side of the gear teeth, as well as the overall quality of the gear, exceeded their expectations in every way. The reversible design allows the customer to run the gear for 10 years in one direction, and then reverse the gear to achieve 10 more years of part life. In all, this project required 12-14 weeks for design, fabrication, heat treating, and delivery. For additional details about this custom large gear hobbing project, contact us directly.


Product Name

Kiln drive gear

Product Description

Split Two Piece Reversible

Capabilities Applied/Processes

Primary: .75 DP , 181.333 OD

Equipment Used to Manufacture Part

CNC Gould & Eberhardt Gasher/hobbing machine,( capacity of 30′) machine and VTL

Overall Part Dimensions

181.333 OD, 14″ gear face

Tightest Tolerances


Material Used


Material Finish

Normalized and tempered

Estimated Part Weight

7 tons

Industry for Use


Delivery Location

MidWest United States

Standards Met

AGMA quality #10



Delivery/ turnaround Time

12-14 weeks