Warco

Sean, I have use a 12mm end mill for squaring off a piece of 1/4" thick gauge plate, a couple of inches in width. Subsequently, when machining some mild steel blocks, the area where the gauge plate was cut was different in appearance, although there was no measurable difference in dimensions. I couldn't see any difference on the cutting edge, so I guess it burnished the edge rather than caused significant wear.

Bill

I bought an TiN HSS set from Warco with my milling machine 2 or 3 years ago and have been using them ever since. Mostly on mild steel and aluminium. They cut well; the finish is reasonable (don't know if it's the best possible), and only one 4-flute is showing signs of losing it's edge on the end. I don't do a lot of milling, hour or two per week, and I flood cool when milling steel in bulk. I also have a 12mm carbide cutter for rough work.

I think how cutters are used matters quite a lot. Early on I ruined a few plain HSS end-cutters by gently rubbing the tool against the work instead of forcing them to cut. For a given tool/material combination, there's a sweet spot between 'too little' and 'too much' force that delivers best tool life. I'm never quite sure when I'm getting it right but have noticed that tools last much longer now than when I first started bodging metal. It's always a comfort to blame poor quality tools, but in my case the guilty party is often me! I am not a trained machinist.

Final point, there's no guarantee that the end-mills I bought off Warco 3 years ago came from whoever their current supplier is. But my experience of Warco has always been good, so why not give them a try...

Dave