Pump shaft key measurements - typically measured from edge or center?

[mechengr12]

On pump shaft drawings that list the depth of the key way is the depth measured on the sides or in the center. If measured in the center then the downward curvature would mean the edges would not be as deep. The drawing does not specify where the measurement is taken from. Is there a standard practice for what the depth is measured from?

 

[MikeHalloran]

Use a micrometer to measure from the root of the keyseat, over the shaft to the other side.
Subtract that from the shaft diameter, and you've got a depth.

Mike Halloran
Pembroke Pines, FL, USA

 

[Lnewqban]

Drawings that list the depth of the key are telling the operator of the mill how deep to cut from the first point of contact of the tool with the cylindrical shaft.

If verifying dimensions after machining is complete, do as explained above.

"Where the spirit does not work with the hand, there is no art." - Leonardo da Vinci