This came home with me from a sale at a local estate of a machinist. Just a flat steel raised platform, measures 11-3/4" x 6". Marked Milliken Machine Co on bottom. I see Milliken Machine was in West Newton MA. What is this & what would one use it for?

a surface plate
less accurate than the granite slabs but plenty good for most measuring jobs.

Hello, Swervncarz. Looks like a cast iron surface plate, or inspection plate. From a Brown & Sharpe catalog; "Brown & Sharpe Surface Plates provide accurate surfaces for tool making, inspection & testing services". Similar working plates also made from granite.


Regards, Lou P.S. As a woodworker, I  would use it as a flattening plate for plane soles, and plane irons.

Thanks, the amount of knowledge here at Papawswrench always amazes me!

As heavy as it is it's more portable than granite! I've got a chunk of pink granite with a custom wood enclosure that I got for 40$. The place I got it from got a 8' by 20' black granite cheap from Boeing. We had an ice storm a couple of days before and carrying it to the van was slow and slipery. It's easier to carry the parts you need to check than move a chunk of granite!

 yes, and using one helps prevent measurement errors that you may get on an uneven bench surface.

   very useful using a height gauge.

Also really good for smoothing a surface.  I use one for automotive things like valve covers, oil pump covers and any surface I need perfectly flat.   Just put a piece of sandpaper on the plate and sand the piece rotating it 1/4 turn each time.