Metric Std for Drill size

[Madhu454]

Hi,
I need your help in defining the right size holes while making the drawings. Is there any ISO metric standard available to know the standard drill size. Can anyone help me to find the standard.

Thanks for your help in advace.

 

[DerbyLoco]

Try ISO 235

 

[drawoh]

Madhu454,

If you are preparing drawings, you should be calling up the diameter you want, with tolerances. Let the shop figure out how to do it. They know.

If you want to know about available drill sizes, check the Machinery's Handbook. There even is a piece on as-drilled tolerances. This is not the same as the tolerances of the drill itself.

If you are tapping holes, specify the thread. Telling the machinists what tap drill to use is an insult.

--
JHG

 

[benta]

Just call out the thread size (M5, M8 etc.).
The machinist will know which drill to use.

Benta.