what are these indicating in the drawing
in the top view, I suppose 5 is the depth, in the front view what's that 5 & 4 showing here
1 Answer
The 5mm and 4mm dimensions in the upper view are specifically for the keyway. That’s kind of obvious. 5mm depth from the tapered surface tangent. 4mm from the end.
The 5mm dimension in the lower view appears to be a superfluous dimension from the stub shaft to the tapered shaft area. The. 4mm dimension in the lower view does not seem to have any purpose.
It is possible the keyway was at one time 90 degrees to its current position and was dimensioned in the lower view. The dimensions were orphaned when the keyway was deleted or moved. They should have been deleted.
Note: its difficult to tell from the drawing but the depth of metric keyways is typically dimensioned from the tangent of the shaft surface. Imperial (inch) keyways are typically dimensioned from a chord line that intersects the keyway sides and the shaft surface.
