A 5/8" hole through a 4" wide beam reduces the load capacity by 1/4. Unless
your beam is oversized you may damage it enough to cause it to fail.


"MiamiCuse" wrote in message
...
I need to drill a 5/8" diameter hole through a laminated beam that is 16"
deep. This beam is sitting 10 feet above the floor across a room support
part of the roof. So I will be standing on a bench drilling from below
pushing the drill up.

I need this hole to be perfectly vertical as I will be passing a rod
through for a ceiling fan.

I know in the past when I had to drill through something much thinner like
a 2x4, I often end up with a slanted hole.

What can I do to ensure my drill is perfectly vertical?

I cannot afford to make a mistake and redrill.

Thanks,

MC