I have a clausing 8520, its 3/4 hp knee mill overall in pretty good shape, probably about 60 years old. Good to hear carbide is a good choice for this machine but they are sure pricey. I used up a box of old new stock HSS bits I got at a good price, now I need to start buying more. Always looking for a good deal, I use the 1/2 more than all others combined, any recommendations on what brand and style of carbide end mill for a small manual machine?
I think I have a tendency to keep using the milling bits a little too long, I should throw them in the dull bit box sooner. I guess looking at them with a loupe and good light as well as judging temperature from color of the chips and amount of smoke? I will order some of the rustlick WS5050
From what I have read, 1 1/2" bit at 600 rpm should be about right for mild steel but I will run it slower if I am cutting thru welds again. I can see how welding can result in small areas that are much harder, probably depending u depending on the base metal, welding rod and technique. Heat treating after welding is a good idea. A lot of my repair work seems to involve machining weldments or areas of built up weld. Its a good idea to always be thinking about other options
I do use this mill more for aluminum than steel, I think these HSS bits will work well for that.
I had wondered if a slight radius or chamfer on the cutting tip would help with life, it certainty does with HSS bits on the lathe. In this case I can see that sides of the end mill have been dulled a little also. It is sort of visible in the photo. I will try the chamfer.