Here are a couple samples from Grove...
the hammerhead was an aircraft 4130 combo that used .035 tubing with custom bends at the hands to ease wrist strain
the hothead was an aircraft 4130 combo that used .028 heat treated tubing, also with the custom bends.
Both models used a unique internal expander that wedged inside the stem and steerer tube so there were no outside pinch bolts to knock your knees on.