They are tappered!
going by a highly inaccurate tape measure outside end is 1 inch and inner is 1 inch and 1/4 or so. Definitely a difference but cant tell how much without more accurate tools.
compared them to a set of Shimano 600s I've got and man are they light. Are the lamberts on the lighter side compared to a standard crankset or are the shimano 600s just bricks?