Newbie needs more help

Greetings and a very happy Friday to all.
Today's project is to hog out holes in the pole mount solar panel rails.
I am using a pair of H beams on an 8' trailer axle (no camber) to set angle of panels towards the sun. One beam rides on each end of axle. I have to drill a 1.5" hole through the 0.170" webs in order to mount the bushing. I am thinking to use a Milwaukee hole saw. Go slow with lots of water to c ool it. Does this seem reasonable?
thanks Bob

On Fri, 15 Sep 2017 07:07:49 -0700 (PDT), PowerSupplyGuy
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More reasonable would be water soluble coolant made for cutting metal or cutting oil. Plain water by itself won't help with the cutting. Hardware stores usually sell little one pint jugs of thread cutting oil. It will work just fine. Don't use motor oil or any type of oil that's made for lubricating. Use an oil that is specifically made for cutting. Your hole saw will last much longer. The threading oils sold in hardware stores is usually sulfurized. This type of oil actually gets between the cutting surface and the work, making the cutting easier and greatly slowing the wear of the cutting tool. Plain water will not do this and will in fact just boil away from the hot chips and cutting surfaces. Eric

wrote:
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Cutting dry works too, as long as you keep the speed down. I drilled holes for up to 4" conduit in steel electrical control boxes without any cutting oil or coolant which would have run into inaccessible places. Go slow and expect the saw to grab. -jsw

What Eric said.
Also, hole saws suffer from not being able to clear the chips. Pecking works, but even better is to drill a couple of small holes, 5/16 would be good, touching and inside the kerf of the hole saw. They will let the chips that build up in the saw teeth gullets to drop out.