Lufkin Micrometer Set: Unique Precision Instruments

LO owns a midcentury “Inside” micrometer set (680A) by Lufkin Company of Saginaw Michigan. Although I know nothing of tools, I found the micrometer story fascinating, and admired the precision of these unique instruments. The value isn’t great for these plentiful tool sets for machinists of all kinds.

The story of the Lufkin Company goes back to the mid-19th century. One inventor got a great idea, make measures for the growing expansion of the country into the West. That country needed lumber, plenty of it, and lumber needed measuring accurately. Something as simple as a devise measuring inches and feet fueled the Manifest Destiny philosophy of the US in the 19th century. But that measuring tool became a game changer. 

Why This Micrometer Changed the World

Note the original fruitwood box for the micrometer. These sets came in three types of boxes, a sliding cover, a hinged box, and plain ole cardboard. Other competitors of this type of tool tend to sell for MORE, such as Logan, Sheldon, Slocomb, Starrett, and Southbound. Not to mention the Swiss made line Brown Sharpe.

Edward Taylor Lufkin, a veteran of the 16th Regiment Ohio Infantry of the Civil War, founded the Lufkin Company in Cleveland Ohio in 1869. He invented measuring devises, and shortly after he began his company he moved the factory to Saginaw, the center of the logging industry at that time. Lumber rolled along the 26 mile stretch of the Saginaw River, and the Lufkin Rule measured most of it. In fact, Lufkin began as a tool maker FOR the logging industry as ET Lufkin Board and Log Rule Manufacturing Company.

Some of Lufkin’s inventions include the first steel measuring tape in the US, now seen at the National Museum of American History. Lufkin’s manager, Fred Buck, in 1919 invented the wooden folding rule. And the company produced the retractable tape measure in the 1940s. In 1976 the company supplied the Olympics in Canada with measuring devices. The company still exists today as Crescent Lufkin, owned by Apex Tool Group, the largest manufacturer of hand tools.

What an Inside Micrometer DOES

Now let me try to tell those that don’t know about tools (as I don’t) what an inside micrometer DOES. Those that DO know, please email me with corrections! Workers used this little kit to measure inside diameters. The primary unit in the box is the stick, in the tubular style, in which the rod is double ended. The rod uses an extension, and the various caps. The rod houses a micrometer rod and cap to allow the length between precisely positioned spherical measuring faces. If the micrometer is clean and undamaged, and not worn, it shows a measurement.

I learned that within a margin of error, a measurement can be accurate, but if outside that margin, the tool is readjusted, calibrated with a gauge ring. These old micrometers are usually collector’s objects and not used for measurements.

What is important to machinists who use these tools is the fit, the finish, the feel of such a tool, and the ease of reading the tool. A cap with a wonky thread for the screw, causes problems as a nick affects how the rod and caps FIT, and the measurement comes out wrong. Once the rod is set relative to the cap, the rod and cap are used to set the other rods. That’s as much as I understand about this little boxed Lufkin set of inside micrometers, number 680 A.

I find them online for $10-25, which seems cheap to me for such history and precision. But I also see hobbyists say  Lufkin was a mid-market tool, not the top of the line. There was a special Lufkin store in Van Nuys, California in the 1960s. This little set could have been purchased there, as the owner worked in the film and TV industry. I’m serious when I say please offer corrections to my tool knowledge!

1 thought on “Lufkin Micrometer Set: Unique Precision Instruments

  1. Tom Conway Reply

    My friend has a Lufkin Co. Cleveland O. Measuring stick that looks like a yard stick but it has multiple overlapping measurement markings on it, with a metal base and handle at top–assuming one uses it in a vertical way. Are you aware of this tool? Any clue what it’s purpose is? I have pictures.

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