Holes in stainless flat stock

[OCNC]

I need to put some 3/16" dia. holes in some 1/8" x 1 1/4" stainless steel (304) flatstock. The holes need to be at a 63 deg. angle from the drilling axis (27 deg. off of the horizontal table surface of the drilling equipment). I don't have a milling machine and want to know if I can do this with a drill press if I'm carefull about feeding the bit and clamping the work. If this is feasible with a drill press what style of end mill should I use? It seems to me that a ball end mill won't try to grab the work the way a square end mill might and won't skid the way a drill bit would. I need to make a total of 18 holes. This is part of a stair railing system for an outside deck.

Thanks for any suggestions.

Chris

[Nono]

I do think it can be done. But with a high speed steel cobolt cutter and a tool change.. Mill the flat for drilling.. Sounds kinda teedious though. How many holes do you have to drill? Try a TTC E20-501-155 at 11.52 Each from https://www.travers.com/index.asp That should do the trick for a high angle. Post some pictures when you get the chance.

[mxtras]

OCNC -

I think this could be done - obviously a mill would be better for rigidity, but -

The problem you will likely have is that the tool is going to grab on both entry and exit - you know this obviously. A carbide tool is likely going to shatter on a drill press unless it is a hefty drill press with a stout spindle. Using cobalt tools sounds reasonable as they seem to be more forgiving to abuse, and a ball end mill is worth a shot. Watch your speeds and keep the tool and material cool somehow - stainless can work harden like a Swedish secretary.

The other thing you could do to help is use a spot drill - a drill with almost no flutes - and use a piece of wood as a drill guide. The bad thing is that spotting drills are typically only two flutes, but maybe you can improvise somehow using some sort of guide.

...just some thoughts - likely not all that helpful. Sorry.

Scott

[OCNC]

Originally Posted by Nono I do think it can be done. But with a high speed steel cobolt cutter and a tool change.. Mill the flat for drilling.. Sounds kinda teedious though. How many holes do you have to drill? Try a TTC E20-501-155 at 11.52 Each from https://www.travers.com/index.asp That should do the trick for a high angle. Post some pictures when you get the chance.

I've got 18 holes to drill. I hadn't thought about making this a two step operation but it makes sense in lieu of using a drill press instead of a miller. What do you think about using a carbide burr with an end cut to mill the flat? It seems like it would be less likely to grab.

Chris

[Nono]

A Carbide Burr would be safer if you do not have the rigidity of a mill, but I suspect that you will destroy quite a few in the process. The key is a very sharp cutter and keeping the cutter cool and free of chips to avoid work hardening. Are you going to build some sort of work holding jig/clamping jig for this?

[ViperTX]

How long is the piece of stock? Have you checked the runout on your drill press...I suspect that you'll wobble through a hole or two if you're lucky.

I suspect the holes are for some sort of spindle? I think your best bet is to drill an undersized hole perpendicular to the surface.....then you could use a reamer, burr, or stone with the drill press or a surface mounted jig to angle the holes.

[OCNC]

Originally Posted by ViperTX I suspect the holes are for some sort of spindle? I think your best bet is to drill an undersized hole perpendicular to the surface.....then you could use a reamer, burr, or stone with the drill press or a surface mounted jig to angle the holes.

The holes are for intermediate rails on the stair railing between the top and bottom newel post of a 5 riser stair. I intend to pass 3/16" rod through the holes and plug weld them from behind. I think the method you've described is the one I'll try. I think a tapered reamer mounted in a drill press should do nicely. Thanks to all for the suggestions. I'll post a picture of the results.

Chris