National Machine Tool was presented with a simple application milling a 10mm wide blind keyway in a 35mm conveyor pulley bore in the material handling industry. We offer metric sizes as well as imperial to facilitate any application. Let us solve your keyway applications with our Keyseat Miller which is easy to use, economical and manufactured in the U.S.A since 1903.

For more information on this project, or the processes involved, see the table below, or contact us directly.

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Keyway Milling of a Coupling/Adapter Project Highlights

Product Name

Coupling/Adapter Keyseat Miller

Problem Description

Metric Bore needs a keyway 10mm wide, 1-3/8″ long and 3/8″ from the bottom of the Bore-no relief hole


Special Keyseat Miller with reduced length pilot mills full depth slot utilizing M42 cutter coated AlTin for better wear resistance

Capabilities Applied/Processes


  • Product Development/Design

CNC Milling
CNC Turning

Keyway Dimensions

10mm Wide
1.375″ Long
0.375″ from the bottom of bore-no relief hole

Tightest Tolerances

Within 0.0002″

Material Cut

316 Stainless Steel

In process testing/inspection performed

Dimensional Inspection, Visual Inspection, Functionality

Industry for Use

Material Handling Industry



Delivery/Turnaround Time

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

Delivery Location

Nationwide/ Worldwide

Standards Met

Customer Specifications, 2D CAD Drawing