Need a K.O. Lee expanding mandrel?  You are in the right spot!  In this post, we detail the history of the company, identify some common K.O. Lee expanding mandrels and explain their features.

First, a little history …

Company founder Knute Oscar (K.O.) Lee was born in 1862 on a farm near Blue Mounds, Wisconsin. In 1887, he moved to Aberdeen, South Dakota, and began operating a farm machinery sales company.

K.O. Lee moved his business many times during the early years, changing his marketing focus as machinery demands evolved. In 1922, K.O. and his son, Clifford Carl Lee, stopped selling implements and concentrated on machine shop activities only. During the 1920’s, an employee named Theodore Purnis invented several small grinding machines and tools to assist in engine rebuilding.

K.O. Lee died in 1934. With the outbreak of World War II in 1939, the K.O. Lee Company, under the guidance of Clifford Lee, devoted its full energies to the production of machines and tools.  This development gained recognition for the company throughout the metal working industry.  After the war came expansion into industrial tool grinders.

The 1960’s and 70’s saw continued expansion and improvement of surface grinders and special slicing machines. In 2008, after a review of market trends, the K.O. Lee Company sold the business to LeBlond.

What Makes a K.O. Lee Expanding Mandrel Unique?

A large bearing surface on all sleeves provides a positive grip on heavy jobs, prevents slip and chatter and holds thin sleeves and bushings without distortion.

Work can be held in any position on sleeve and may overhang on either or both ends for facing operations.

Precision ground arbors and sleeves provide accuracy of 0.001″ (0.025mm) or better. A large bearing surface minimizes wear.

Common K.O. Lee Mandrels

 General Purpose: For tool room, home shop and light production work

K.O. Lee Expanding Mandrel KM2

Mandrel: KM2

Use: Sized to fit 11/16” to 1” (17.46 to 25.4 mm) holes

Heavy Duty: For production line operations including heavy roughing cuts

Mandrel: KM6 (pictured at top of post)

Use: Sized to fit 4” to 5-½” (101.6 to 139.7 mm) holes

K.O. Lee Expanding Mandrel KM5B

Mandrel: KM5B

Use: Sized to fit 2 ½” to 3 ¼” (63.5 to 82.55 mm) holes

An Expandable Mandrel Saves You Money

The beauty of K.O. Lee expanding mandrels is that just one, with a wide range of expansion, can be used to replace multiple individual mandrels, saving you time and money. Like a multi-head screwdriver, you have a variety of utilities in this indispensable tool to tackle any job in your shop or classroom.

If you need K.O. Lee expanding mandrel parts, click or tap here.

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We look forward to hearing from you!