Plastic Plugs for SHCS Cbores

[JakeL]

The majority of our fixtures have holes and cbores in them to fit a 1/2-13 SHCS (Ø.531 thru w/ Ø.781 x .531 deep cbore). When we go to blow off the fixtures, the cbores are a nuisance. Some kind of plastic cap to cover the cbore would be nice. 

Anyone have any recommendations for a solution for this situation? We were thinking something on this idea: https://mocap.com/plastic-caps-straight.html#SZCHARTID

I'm guessing we'll have to start machining the cbores slightly larger dia to account for the plug. The plug also needs to sit below the surface so cbore might need to be machined deeper.