The JT Slocomb Co Archive

09/12/2025

This rare J.T. Slocomb Snap Gauge Micrometer No. 36 is more than just a micrometer—it’s a thread gage with a 14–20 P.U.S.S. thread, making it an unusual and highly collectible piece of machinist history.

Designed for inspection and production work, the Slocomb Snap Gauge eliminated the need for multiple standards by allowing quick, repeatable measurements. Truly a testament to the era of rugged, long-lived precision tools.
A rare find for collectors and tool enthusiasts alike!

08/02/2025

We were able to add another piece of original ephemera to the Archive collection.

This will be the third branded envelope that we now have.

This envelope was mailed on November 2nd, 1933 at 6:30pm.

There is nothing printed on the reverse side, unlike previous examples from 1915.

We will have this preserved and framed soon.

06/29/2025

Here is another advertisement in our collection from December 2nd 1909, which makes this 115 years old.

The tagline used , “If you’re going to be inaccurate, you might as well not measure at all” is great and one of their best mottos.

05/10/2025

Here’s an advertisement from 1917, 107 years ago

The larger sizes were being pushed more as they weren’t as common before Slocomb marketed them.

They also offers a rack for them as well to keep them safe and organized.

If anyone has any of the larger racks, please let us know! We haven’t found or seen any of the larger racks throughout our research.

11/16/2024

Here for Micrometer Friday we have the model No. 26 J.T. Slocomb Drop Forged 1” Inch Micrometer.

It was produced as early as 1903 as seen in catalog No. 8. (Mark Stansbury Collection)

An article in “American Machinist” published on January 26, 1911 explains and shows the method of manufacturing of this micrometer.

The frame of this Caliper like our others is drop forged from bar steel.
It is then highly polished and next pressed in a polished die under a hydraulic pressure of 300 tons to the square inch, raising the figures showing decimal equivalents.
The raised edges and figures make a surface that is almost a knurl, and is a good finger hold. The figures are always bright, and show plainly.
The pressing also stiffens the frame materially.

Additionally, this drop forged frame was used with slight changes as the basis for the model No. 35 Direct Reding Micrometer.

10/21/2024

From the American Machinist trade magazine, published on 11/26/1941 comes the loud and bold advertisement showing the precision dual head snap gage micrometer.

10/11/2024

For Micrometer Friday, we have acquired a rare and unique piece of J.T Slocomb history!

This is a commemorative 100 year anniversary micrometer celebrating a century of JT Slocomb’s continued manufacturing of micrometers.

This special micrometer is based on a unique and very uncommon version of the SpeedMike, (the updated version of the Davenport-Slocomb Direct Reading Micrometer, model No. 35). What makes it different than most other SpeedMike’s, is the addition of a second set of digit windows on the reverse of the micrometer. Normally only the obverse had them.

Also included with this micrometer is the solid leather holster with embossed company information. This is the second style of SpeedMike holsters that were offered, and we will have a post coming soon about them.

One thing that we noticed that has us without an explanation, is the first date of 1891 as the starting year when Slocomb began its company. Written by J.T. Slocomb himself in the August 1915 edition of “Machinery”, he states that the company was founded in 1893. We do not why the dates do not align, and it has us wondering.

We have not uncovered any I formation surrounding this micrometer, whether it was sold to the public as a special edition, or if it was an internal company promotional item. We are continuing our research to uncover more information about it, and will follow up once we know more.

Have a wonderful weekend!

08/24/2024

We are thrilled to announce that:

The J.T. Slocomb Catalog No. 27 has been digitized and uploaded to Archive,org.

The link is located here: https://archive.org/details/JT-Slocomb-Catalog-27

As always, this will be completely accessible for free, without a charge, subscription, or signup required. Knowledge should always be free and not withheld.

This unseen until now catalog, is the first catalog from the Glastonbury period. After years of research without locating or seeing anything at all, this catalog appeared out of nowhere, and we were grateful to be able to acquire and add this into our Archive collection.

This is groundbreaking for research, and the history of JT Slocomb's time after relocating to Glastonbury RI, leaving the original location of Providence RI.

Until now, model numbers and how the system used to assign a model number was essentially unknown. Before seeing this catalog, we were in the process of researching and cataloging every micrometer with a box that had a printed model number, and creating a database from that information. We had documented about 250 or so examples, and slowly understanding the numbering system.

Our next step in documenting and presenting this newly learned information, is that we will be building a library and index of tools offered during the Glastonbury on the Archive's website. This will be slightly different from the Providence era index, due to the lack of model number examples in this catalog. So we will document the micrometers in our collection to show what that model looks like. Outside sources will also be used as well.

Coming soon of digitized catalogs and ephemera, is Catalogs No.s 14, 17(American Version), two 18 versions, and a few different versions of No. 16. Additionally, we have a very large backlog of never before seen documents and ephemera showing new history of Slocomb.

That is all for now, have a wonderful weekend everyone!

J.T. Slocomb Co.: Catalog No. 27 - Slocomb MicrometersEdition 27Published in February 1974  

08/10/2024

We are working on making archival covers for the Archive’s collection of J.T.Slocomb catalogs.

From archival stock, each cover is custom fit, and hand cut for size.

We take pride in our efforts to preserve and provide from our collection.

Coming soon, we will be digitizing and processing catalogs that up until now, have not been available to see, and learn from. Additionally, we will be documenting and digitizing “updated” price sheets that were later added to catalogs.

It has been a while since our last update, and following updates will be slow for a while, but we are still active and will continue to preserve the history of the J.T. Slocomb Co. and all of its history.

We have a massive backlog of new additions to our collection, new posts, pictures, information, and much, much more that will be shown in time.

Additionally, our store is open for repair parts currently, and will soon be updated with many more items, as well as newly offered services provided for all Slocomb micrometers.

Thank you for continuing to support us, and as always, please continue to share knowledge and keep history alive.

04/27/2024

You won’t believe what is on pic no. 7!
This has been a project that has been on the back burner for a while now. We have bifurcated the thimble assembly on this 1” micrometer with a jewelers saw and have exposed what normally can never be seen. With the internal assembly split and exposed, we can now easily see how the pre-loaded wear compensating and adjustment nuts work and carry out their purpose.

We aren’t quite finished with this little project. There will be more to come with it, and you won’t want to miss the final product!

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04/26/2024

Today we have pulled from our archive, a Glastonbury Era 0”-1” Blade Micrometer. This micrometer, and other sizes like this, were first offered in the early 1960’s up until the late 1980’s from our research. These are quite unique as the anvil on the spindle does not rotate and keeps it’s plane to the fixed anvil throughout its operation. Even though the design and internal construction differs from standard Slocomb micrometers, it still retains and features the same patented adjustment and wear compensating assembly that J.T. Slocomb famously patented.

This mic was manufactured approximately 80 years after the original design was patented, and will easily continue to be in service for another 80 years without any issue.

J.T. Slocomb invented and manufactured high quality tools, that to this day still perform with precision and durability.

There is a reason every manufacture has copied the design and patent that Slocomb invented for micrometer frames, and since then, has been the industry standard to this day.

04/25/2024

This micrometer has been on an incredibly long journey throughout its lifetime. By far the is the furthest away we have ever had a micrometer travel to us for our collection. At an astounding 6,504 miles away, all the way from Dnipropetrovsk, Ukraine, and easily estimated over 12,000 miles traveled since its manufacture in the mid 1930’s, this is probably the longest distance a Slocomb micrometer has traveled. Dnipro’s main industry is in the metal trade, and this mic must have been quite the investment when originally purchased. This mic has been well used, but extremely well cared for. It is unusual for a mic of this age to have perfectly functioning friction stop, thimble lock, and original spring with little to no wear on the spindle. We are proud to have this well traveled micrometer in our collection!