Put an engine in a 94 F150 a couple weeks ago. Worst part was digging out SAE tools. Stuff that attached to the block or heads was SAE, rest was metric. Hodge podge of head sizes though.
Tim_S said:...I didn't know fasteners with SAE thread and a metric head (or vis-versa) even existed until this thread.
They've existed for a long time. My 1960 Schwinn Corvette came with 7/16" head nuts to fit on the 6mm threaded (Swiss-made) brake pads. Its German-made pedals, like nearly all pedals, are for 15mm wrench, but 19/32" is close enough to work.
Spark plugs had inch-sized hex with metric threads even further back.
Tim_S said:...I didn't know fasteners with SAE thread and a metric head (or vis-versa) even existed until this thread.
They've existed for a long time. My 1960 Schwinn Corvette came with 7/16" head nuts to fit on the 6mm threaded (Swiss-made) brake pads. Its German-made pedals, like nearly all pedals, are for 15mm wrench, but 19/32" is close enough to work.
Spark plugs had inch-sized hex with metric threads even further back.
Spark plugs have always used metric hex its just happens an SAE size will fit it. 12mm, 16mm (5/8), 18mm and 21mm (13/16) being the most common. The first functioning, patented and produced spark plug was from Robert Bosch in Germany which did not use SAE.