I'd seen these wrenches, made by the H and E Wrench Company of New Bedford, Massachusetts, in antiques stores for way more than I wanted to pay for one. I finally came across an affordable one last week.
The company's slide-adjusting nut wrench was described by patent #1,391,179, filed by Hemphill and Evans in 1920 and issued on September 20, 1921. This patent was assigned to the Universal Tool Company, a Utah corporation and presumably an earlier venture by the inventors.
Its double-threaded adjusting screw, after being cleaned and greased, still works easily. Guys at last night's Man Cave meeting pronounced this wrench as the one they liked best from the collection!
These wrenches were made of super hard steel. I have never seen one with mushroomed jaws. Has anyone run a Rockwell Hardness test on this wrench?
I tried motor oil as the adjusting screw lubricant, but it didn't work that well. Then I tried Sil-Glyde, a silicone impregnated grease manufactured by the American Grease Stick Company in Muskegon, Michigan, which worked much better. Any alternative lubricant suggestions will be tried next time this wrench gets cleaned.