- Micrograin Carbide Square End Mill - 4 Flute - ISE1/4 4T (5 Pieces, 1/4") - 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.

These are excellent value for money! My machine shop uses these every day and they're great!

The design is a good one, but the execution is superb. I got the pkg. of five ⅛ in bits. I immediately tested it on the door latch for my new front door dead bolt. The strike plate already there meets the highest safety standard, which is done by the use of certain steels, their thickness, and the means by which they're attached to the door frame. The problem turned out to be that it was slightly off and it got in the way of the bolt extending. I spent a half-hour hand filing that thing to get it to work. When the bits arrived, I decided to see if I could use my Dremel tool with this bit to even everything off. Wow! What a great purchase. After juxtaposing the hand filing with the use of the bit, separated by less than 24 hrs, I'll never forget I have it when it can be useful and I know I'm going to be glad I do. This is a piece that is overkill for us mere mortals. It's meant for CNC gods.

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.

Works good on my 1923 endmill

I used these bits in a Foredom jewelry engraving tool along with some StayMax Metal hollow number guided to engrave numbers in my beer flights project. Then I mixed powdered turquois in resin to make these numbered holes.

I have been using end mills for 30 years now. These are very good end mills for the money. They are not Hurricane, but you didn't pay Hurricane prices either. These are sharp, and hold their edges well. However, you need to know that this is also a specialty item. You are buying solid carbide because the job you are doing requires an end mill harder than the work piece. And at 1/8 inch, solid carbide, even the slightest wiggle will shatter it. You cannot have RC65 and over without being brittle. The picture, trying to end mill a hole to remove a broken bit that was about as hard as the end mill. First end mill grabbed and shattered. Went in again, second end mill finished the job.

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.