Boston Gear - ECATALOG
Boston Gear produces a variety of custom and stock gears.
Rapid Gear - Gallery
Rapid Gear produces custom gears using shaping, grinding, and wire EDM.
RushGears.com - Product List
RushGears.com produces a variety of custom gears on short turnaround times. They have a custom gear generator to assist with quoting and gear selection.
KHK Stock Gears - Online Catalog Page
This page has an online, interactive catalog and PDF catalogs.
QTC Gears - Products
This page has an online, interactive catalog page.