A repeat aerospace customer recently engaged Duval Precision Grinding to produce a new run of steel stepped shafts requiring precision OD grinding services. The order included three part numbers, each a cylinder measuring 7 inches in length but with different outer diameters. All parts required four OD grinding operations and four precision chamfers per piece, with tolerances tight enough to ensure optimal bearing fit and reliable long-term performance.
Initial Challenges in OD Grinding Steel Stepped Shafts
While the parts shared the same length, the varying diameters and stepped geometry made this project complex. Each diameter required its own setup, and the grinding process had to maintain strict concentricity across all features. Chamfer angles and widths were also critical, ensuring both proper assembly fit and reduced stress concentrations in service.
In the initial production runs, achieving this level of accuracy was possible—but the process was labor-intensive, with extended changeover times that slowed output and increased cost. The customer wanted a solution that could deliver not only on precision but also on efficiency to speed up processing times.
Streamlining the OD Grinding Process for Multi-Diameter Shafts
Rather than accept slow turnaround as inevitable, Duval’s engineers re-evaluated the workflow from the ground up. The team developed a process that could handle all three part numbers more efficiently while still meeting aerospace-grade requirements.
Key to this improvement was the design of custom fixturing capable of securely holding multiple diameters without sacrificing concentricity. The grinding sequence was reorganized to minimize handling, and chamfer grinding was incorporated into the same setup, reducing cumulative error and ensuring uniform edge quality.
Results: Faster Turnaround and Consistent Quality
The impact for the customer was immediate:
- Reduced lead times for both small and high-volume orders
- Consistent dimensional accuracy and surface finish across all part numbers
- Lower per-unit cost through improved process efficiency
With these gains, a once time-consuming, high-cost job is now a repeatable and cost-effective operation. While the measurable gains in lead time and cost were significant, the greater value came from the process knowledge developed along the way. Precision grinding—particularly for multi-diameter parts like stepped shafts—relies as much on process design as it does on operator skill or equipment capability.
Every setup decision, from fixture geometry to inspection protocols, influences both part quality and production efficiency. By taking the time to engineer a repeatable workflow, Duval not only improved this specific job but also created a framework that can be adapted to future projects with dimensionally proportional variants of the same component.
Design Tips for Multi-Diameter Parts Requiring OD Grinding
For engineers, evaluating the interplay between part design and grinding process parameters can help avoid costly production bottlenecks. This project highlights several considerations engineers can apply when specifying parts for precision OD grinding — especially multi-diameter components like stepped shafts:
- Allow Adequate Relief Between Diameters
Small relief grooves or undercuts between diameters can make fixturing easier, reduce tool interference, and improve chamfer consistency. - Standardize Chamfer Geometry Where Possible
Keeping chamfer angles and widths consistent across part numbers allows for more efficient tooling and setup, reducing cost and lead time. - Match Tolerances to Functional Requirements
Overly tight tolerances increase machining time and inspection frequency. Specifying tolerances that meet performance needs — without unnecessary tightening — can have a significant impact on cost efficiency. - Consider Multi-Feature Machining in One Setup
Designing parts so multiple features can be ground in the same fixture minimizes part handling, reducing the potential for cumulative error and improving dimensional repeatability.
By incorporating these considerations during the design phase, engineers can help ensure production grinding processes are both precise and cost-effective.
Precision OD Grinding Expertise for Aerospace Components
By re-engineering the workflow for OD grinding steel stepped shafts, Duval Precision Grinding transformed a complex, high-precision job into a streamlined and repeatable process. The result meets aerospace specifications, reduces cost, and shortens lead times for the customer—demonstrating the value of combining technical ingenuity with process discipline.
If your project requires precision OD grinding for complex geometries or tight tolerances, Duval has the expertise, equipment, and process control to meet your specifications. Request a quote today to see how we can help bring success to your next precision grinding project.
Consistency is just what we do.
Contact us to discuss your project and learn why engineers choose Duval Precision Grinding—time after time, part after part.