Gleason P 400G

New Gleason P 400G machines price between $600,000 and $850,000 depending on configuration. Base machines with manual loading and standard dressing start around $600,000. Adding automatic workpiece loading, enhanced dressing systems, in-process measurement, and closed-loop quality integration pushes toward $850,000. Used Gleason profile grinders from 2015-2022 trade between $300,000 and $500,000, though the specialized nature of gear grinding machines limits secondary market availability.

Profile (form) grinding uses a wheel dressed to the exact tooth space profile and grinds one tooth space at a time, producing the highest accuracy and surface finish. Generating grinding uses a threaded wheel that meshes with the workpiece in a continuous generating motion, grinding all teeth simultaneously for much higher productivity. Profile grinding achieves DIN 1-3 quality while generating grinding typically achieves DIN 3-6. Choose profile grinding for noise-critical and ultra-precision applications; choose generating grinding for high-volume production where DIN 5-6 quality is acceptable.

The P 400G is capable of producing gears to DIN 1-3 quality (equivalent to AGMA 13-15), the highest gear quality grades achievable. In production environments with proper process control, DIN 2-4 is routinely achievable. Gear quality is measured across multiple parameters including profile form deviation (ffα), profile slope deviation (fHα), helix form deviation (ffβ), helix slope deviation (fHβ), and pitch deviation (fp). The closed-loop quality system helps maintain these levels consistently across production runs.

The P 400G is primarily designed for external gear grinding. Internal gear grinding requires specialized machine configurations with extended grinding spindle reach and different wheel geometries. For internal gears, Gleason offers dedicated machines or the P 400G can be configured with internal grinding attachments for limited internal gear work. Most shops requiring both internal and external gear grinding maintain separate machines optimized for each application.

The P 400G supports both CBN (cubic boron nitride) and dressable vitrified aluminum oxide grinding wheels. CBN wheels offer longer wheel life and faster grinding speeds but cannot be redressed to change the tooth profile — ideal for high-volume production of a single gear design. Vitrified wheels can be redressed to any profile using the CNC diamond dresser, providing flexibility for job-shop environments with diverse gear types. The choice depends on production volume, gear variety, and cost optimization priorities.

Gleason's closed-loop system connects P 400G grinders with Gleason gear inspection machines (like the GRSL or 300GMS). After grinding, sample gears are measured on the inspection machine, and deviation data is automatically transmitted back to the grinder to correct grinding parameters. This eliminates manual data entry errors and reduces the time between detecting a quality drift and correcting it. The system maintains statistical process control data for quality documentation and continuous improvement.