SPEED TIGER Micrograin Carbide Square End Mill - 4 Flute - ISE3/8 4T (1 Piece, 3/8") - for Milling Alloy Steels, Hardened Steel, Metal & More – Mill Bits Sets for DIYers & Professionals

Sharp and true. Does what I expect from a carbide end mill.

Bought these for a hobby. Received them and like that they are packaged individually, thus helping keep them sharp. Used them on a firearm building project and only eneded up using one. But stayed sharp and met the needs of what I was using it for. If your are a hobbyist and looking for some high quality milling bits with out having to pay a premium these are the ones to go to.

UPDATE: I upped my rating from 2 tp 4 stars. Customer service was very helpful and responsive. They actually contacted me when they saw my original review. I found that my spindle speed was too slow. Obviously it depends on the material but these bits have to be spun pretty fast and the depth and feed rate must be shallow and slow as well. My mill only spins at max 2800rpm. So I spun it at 2800rpm and took a more shallow cut along with a slow feed rate and these things cut pretty decently. I assume they would work better at an even faster spindle speed. They are still very brittle and will snap if you apply to much side pressure. Overall they did the job I needed them for.Item came packaged well and they looked good. I ordered the 1/16th size and these things snap at the slightest pressure. I almost messed up my project so I had to discontinue using them due to them snapping so easily. I tried another set I had and had no issue.

Have had great success on drilling 1/4" AR500 steel with this in a drill press. Had 1 snap due to my handling, but the 2nd bit has already lasted 140+ holes in AR500.Of course used oil on each hole.

Nice cutters. They're doing a fine job. A good value.

I’m pretty sure that I;m never buying another end mill that ISN’T a Speed Tiger. I’d broken my only two carbide mills trying to alter a badly machined Arbor, so I grabbed a 5 pk of Speed tiger, in the size I needed, thinking I’ll probably break them all trying to mill this hardened tool steel. …i put the first Speed Tiger in my mill, and off we went. This thing was begging for me to feed it faster, i finished the job in two passes through the crunchiest hard steel i’ve ever milled…this stuff sounded like milling glass. ….the Speed Tiger breezed through it like i was cutting half melted aluminum, and was still as sharp as it was when I cut myself on it, mounting it, the first time.I was really shocked that it was UNphased by the crunchy hard steel that broke my other bits. …i’ll never need the other 4 that I bought… I guess they just put the other 4 in the pack, for emotional support. 😳I really hope that I can afford some larger sizes.

I keep buying these to replace my hss end mills. They are awesome, and cut like a hot knife through butter. I cut a lot of 416 stainless and these make hss look like junk. Almost no burrs to file off even after cutting a keyway in a threaded shaft. Definitely a must.

Held up very well cutting 304 stainless even under sub-optimal feeds and speeds, which were the limitations of my CNC. I tried another (different brand) popular carbide end mill on the same job / stock subsequently for comparison. The other end mill ground itself into a needle due to intense heat. But this Speed Tiger came out of the same job intact and still sharp.