Ads you saw with sledge hammer were probably columbian. They are made of maleable iron and don’t crack (except for the tool steel jaws). Ductile iron wasn’t patented until the late 1940’s.
Thanks. Been lurking here for some time. Dunlap was free. Other two cost me $120 each.
Have a Chinese prograde 6 inch that is a POS. Had a Chinese Wilton 5 inch swivel/rotate combo that I gave to my son. The craftsman 5181 mentioned a few pages back is still listed on CL. I live about 20...