Hi all, a general question to all engineers out there regarding dimensioning of hole depth in drawings. In hole wizard, the hole depth is defined as the distance from the surface to the cylindrical edge (5 mm in the example) below. If you measure from the tapered point, the depth is slightly more at 5.75 mm.
- In the hole callout, do you specify 5 mm or 5.75 mm? Is there a universal convention for this? How do machinists interpret the callout?
- Is it customary to provide a detailed cross-section to prevent confusion?
As a rule I would dimension that drilled hole depth to 5mm.
As a machinist I would interpret the depth of the drilled hole to 5mm unless I saw the words "To drill tip" in which case I would interpret the depth to be 5.75mm..If the depth was dimensioned to the drill tip I would also expect the angle of the drill tip to be specified.