Chain drilling is likely to create problems, not solve them.

Milling cutters, especially in these small diameters, are much better in homogenous material. Chain drilling leaves lots of “teeth” that could snatch the flutes, possibly breaking the cutter.

You don’t say how precise the slot has to be, but if it is critical, e.g. a keyway, it may be better to use an under-size cutter first along the centre-line then gently take the sides out to finished width.

Slitting saw will be the easiest but you may have to do a bit of reshaping when it is cut. The forces within the sheet may well cause the material to spring apart either side of the slot, it may also widen. Do a test on the material before cutting your final piece.

I had assumed the slot was not open ended, maybe the OP can confirm?

If you are cutting a slot and the end is not open, then only drill a hole at one end. Running into a hole can be the cause of damage o the cutter. Cut with a small depth of cut and having a vacuum cleanser or some other suction device to draw away the swarf will make the cutter last a lot longer. Having the material clamped is also important. A cut depth of 0.1mm to 0.2mm id being realistic at a fine feed. Only feed in 1 direction, as if you feed in both directions, you can have an oversized slot. If the end if open, no need for a drilled hole. Ideally to make a 1/16 slot, would cut with a 1.5mm cutter first, and then finish each side, or finish with the 1/16  cutter at full depth with a slow feedrate. Slow being at a rate of 0.01mm to 0.02mm feed per tooth. So at 1200 rpm, the feed rate will be 24 to 48 mm/min or 0.5 to no more than 1mm per second feedrate. You can use this rate for the roughing out too but at lower depths of cut.

Since the slot is only 1/2″ long and closed-ended, I’d have thought that slitting saws, bandsaws and hacksaws seem rather ruled out. A slot drill, as opposed to an end mill, should cut to accurate width if that is important. A 1/16″ end mill might cut a trifle over-size.

Clive

The usefulness, or otherwise, of a slitting-saw [in the ‘closed slot’ version of the job] would very much depend upon its diameter.

MichaelG.

Thanks John, I missed that.