Drilling holes on 210 struts is done.
Procedure of drilling two 9.6 mm holes on the strut
– apply two punches each end of the pipe
– drill two holes size of 3.0 mm or little bigger
– drill two holes size of 9.6 mm (Two or three drops of tapping fluid per hole)
Today I drilled 120 to 140 struts. I managed to drill 202 holes using one 9.6 mm bit. Two or three drops of tapping fluid by the syringe per hole worked out pretty well. I think I spent 70 to 80 cc of tapping fluid overall.