Cutting a blind keyway

[Pete O]

I finally got a chance to get back to the mill this afternoon and make another attempt on the keyway. I am pleased to report that the second attempt turned out spot-on, thanks to all the advice from here. I used a 5mm slot-end-mill-cutter thingamajig to rough it out, then finished it with a 1/4" cutter that i found amongst my stuff that has 2 very short flutes. A close inspection under the magnifier revealed that the corners of the cutter were very slightly chipped, so I took a couple of brave pills and sharpened it on the bench grinder- came up a treat. As did the keyway. The key went home snugly with a little tapping.
The cutter I used has 2 flutes, with different length edges on the end so that it centre cuts. Does that make it an end mill or a slot cutter? Pretty much all my cutters have been bought in batches from clearing sales so I have never actually ordered them by name.
I have to admit that I cut the second keyway at 90 degrees from the first attempt, rather than start the whole job again. Please don't tell anyone .