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America on the Move
Collection Exhibition Themes
Machinist's Divider, used at Spencer
Currently on display
Not a part of the official Smithsonian Collection
This divider used by machinists at Spencer Shops
Physical Description
Machinist's Divider, steel
Date Made:
North Carolina
Type divider used commonly
Lent by North Carolina Transportation Museum

Part of a small array of hand tools displayed in "America On The Move" - such tools were used in the inspection and repair of steam locomotives. Light repairs on steam locomotives were usually done in roundhouses at the many small locomotive terminals throughout a railroad's system; heavy repairs were done in a large, centralized repair shop serving the whole system (often referred to as the "Back Shop"). Most of these tools date from the early- to the mid-20th century, roughly 1900-1955.

Machinists used calipers to measure the sizes and diameters of parts against a standard size or diameter, or to compare a dimension on one part with the same dimension on another, similar part. A large caliper like this one was used by a machinist when operating a large lathe or vertical boring mill, making very large parts. The lathe might be an immense wheel lathe, one that "trued" the wheel treads of locomotive and railroad-car wheels. Or it might be a lathe for axles, in which the outer ends of each axle were machined for later fitting of wheels by a wheel press.

A machinist used a divider to transfer a measurement from one part to another being made, or to scribe marks to ensure accuracy in making a part with a lathe, planer, boring mill, milling machine, or other machine tool on the shop floor.

Related People, Places, and Events
Related Place
Spencer Shops of Southern Ry, Spencer, N.C.

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