A customer in the pump manufacturing industry identified an application with a keyway that was milled into a treaded bore located above a smaller through bore without a relief hole. This keyseat miller would be designed with a long pilot passing through the threaded bore and bearing into the lower smaller bore. We then milled a slot in threads without breaking into the smaller bore with finished dimensions of .625” in width and .310” in depth. Dimensional, visual, and functional inspections were completed to ensure manufactured tolerances within +/- .0002”. At National Machine Tool, our lead time for stock items is 2-3 days and custom items in 2-3 weeks. For more information on this project see the table below or contact us directly.

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Custom Cut Blind Keyway in a Bronze Sleeve Project Highlights

Product Name

Pump Sleeve Keyseat Miller

Problem Description

Keyway milled in threaded bore above smaller through bore without a relief hole


Keyseat miller designed with long pilot passing through threaded bore then milling slot in threads without breaking into smaller bore

Capabilities Applied/Processes


  • Product Development/Design

CNC Milling
CNC Turning

Keyway Dimensions

Width: 0.625″
Depth: 0.310″

Tightest Tolerances

Within 0.0002″

Material Cut


In process testing/inspection performed

Dimensional Inspection, Visual Inspection, Functionality

Industry for Use

Pump Manufacturing



Delivery/Turnaround Time

Stock Items: 2 – 3 Days
Custom Items: 2 – 3 Weeks

Delivery Location

Nationwide / Worldwide

Standards Met

Customer Specifications, 2D CAD Drawing