Honing on 6061

[buckeye]

Greetings all.

I need a .723" bore +/-.0005 in a piece of 6061. Im considering drilling 23/32" (.7188") Then finishing to size with the hone. Would it be possible to rub out all the drill marks and leave a smooth finish with .0042" honing allowance?

Thanks,

Buckeye

[Conrad Hoffman]

Maybe with a reamed hole, not sure about drilled.

[V Semionovas]

I don't have much experience with honing, but I believe aluminium is too soft to be honed, wont the abrasive grains get inbeded in the metal?

how about pushing a bearing ball tru it?
Vladimir

[buckeye]

you can buy the correct stones, just not sure if it will be enough material to clean-up.

[Ken hosford]

There is a cart some wear on probable hole size from drilling . I would say no it is probably not stock left to clean . unless you do not need 100 % clean . I agree a reamed hole yes . Ball broaching maybe

[Davis In SC]

A few years ago, I built some "Short Run" molds from 6061-T6511. There were quite a few ejector pin holes that need to be sized to a snug slip fit for the ejector pins. I carefully located, spot drilled and reamed these holes at .002 under, and then honed them using a standard Sunnen stone that is used on steel. I used very low out feed pressure, and copious flow of oil. Holes came out perfect, molds are still running , long after ther should be worn out.. Just be careful not to damage mouth of hole as hone enters.. HTH

[buckeye]

Thanks, this too is a short run, but I need a truly round profile and a good SF. Boring would probably work, but the powers that be refuse to buy the proper tooling, and I dont have the time to make it myself.

[split tenth]

I would leave about .010 per side.Rough with a coarse stone,finish with a finer stone.The stock will come out fast. Use a lot of oil.Check for stone loading.Open up the stone with the diamond dressing tool that comes with the machine.The part will heat up fast so watch the temperature if you're trying to hold .0001.You did not mention the bore length.The hone likes a long bore,does not like a short one.

[buckeye]

Originally Posted by split tenth

I would leave about .010 per side.Rough with a coarse stone,finish with a finer stone.The stock will come out fast. Use a lot of oil.Check for stone loading.Open up the stone with the diamond dressing tool that comes with the machine.The part will heat up fast so watch the temperature if you're trying to hold .0001.You did not mention the bore length.The hone likes a long bore,does not like a short one.

Ok, the next drill step down would be to leave .018" diameter. The bore is about 5.950" in length. What grit stones would you use to rough and finish? I would like something near a 20 micro-inch finish.

[gappmast]

Honing aluminum is not problem you will want to use an silicon Carbide stone. Use a 220 grit for stock removal and it will give you about a 50RA finish. 280 grit will give you a 33 RA and a 400 grit will get you to about 16RA.

As for stock needed to hone it depends on how well your drill cuts. If you have a good drill and it does not wander (bannana shape hole) .010 on diameter should be more than enough. If the drill tears or wanders you will need more.

Don't worry about inbedding grit aluminum is honed all the time with no problem.