STAR

Star is an alternate brand of Scientific Instruments Co. (SIC). See the model 250 below for proof.

Star No. 25 "Sliding Disk"

A nice 3 1/8" diameter rule constructed and styled exactly like the Scientific Instruments rules, and so presumably from the same source.

This one is in new condition, and came with the box, vinyl case, plastic overwrap and the manual (for a No. 250).

In a dead giveaway of rebranding, the "MADE IN JAPAN" text on the cover of the instructions, as well as the info around the rule's hub depicted in a diagram within them, are plainly stamped post-printing.

Star No. 250 "Sliding Disk"

The 250 is a duplex rule. It's the same as the 25 (a simplex rule) on the front, but on the back sports trig scales.

It is identical to the SIC No. 250, right down to the patent number, 440028.

The image above is of my Star 250 showing Patent number 440028.

This one is of an SIC 250 c/o the International Slide Rule Museum. Click to zoom in and see the matching patent number on the right-hand image.