SpeTool Tapered Ball Nose End Mill 1/4" X 3" with 0.5mm Tip Diameter(0.25mm Radius) Ball Nose 5.26Deg for CNC Machine Engraving Carving Bits H-Si Coated

Very sharp well designed and works perfectly on my CNC router.

These are great bits. Sharp and long lasting. I used one bit to do an inlayed cutting board. It was used to cut maple, walnut, Purple Heart, padauk, and yellow heart. All cuts were clean and sharp!

Worked beautifully!

I bought these in April or March of 2018 for a CNC router. I build all sorts of stuff with it but I bought these for detailed work. The diameter of the top is 1/2 mm (radius is 1/4 mm). They hold up very well for several uses each if you aren’t making your cuts too deep (1 - 5 mm deep) and if your cutting speed isn’t too fast. My CNC machine uses a Dewalt dwp-611 router. I usually make the cut speed ~750 mm/minute and adjust the spindle speed to the wood or material in cutting. For detailed work, I’m usually using hard wood (salvaged from good solid furniture at the thrift store - don’t buy fresh cut stuff unless you really have to). Anyway, with hard wood, the spindle in my dewalt is set to 4 - 6 (out of 1 to 6). If you try to cut 1/2” wood with this bit in a single pass, you’ll tear this bit up in a minute. If you make your cutting speed much faster than 750 mm/min, it will get dull and probably lose its tip during the first project (and your quality will suck). I know because I’m a hobbyist and I’ve destroyed many bits (including these) learning these lessons. For the price, these bits are well above average and you will get many many projects out of each one of you can be patient and manage the speed and depths appropriately.

As advertised. Used on a shapeoko (probably misspelled that) to engrave on aluminum. Hardest part was getting the correct feed rates so that the bit isn’t over stressed. Have had a few snap but i can’t tell if it’s user error (feed rates/extended use) or quality. Leading more towards the user error hence the 4 star rating.

These bits are impressive. They provide for precise CNC carving.

I accidentally had my CNC machine set up wrong and had the bit deeply ride over 6 nickel guitar frets and I was amazed that it didn't snap such a tiny bit (see photo). This bit is impressively durable.

I had heard positive thing about SpeTool so i bought this 2 flute bit for less that 1/3 the price of and Amana 3 flute bit. So far it has performed excellent . i an cutting .25"-.3" in a single pass at 20ipm. I don't expect it to last as long as one Amana bit but I do know that Three of these will last longer that 1 Amana bit.