Originally Posted by ger21  HSS bits won't last a minute in mdf. Carbide is mandatory. |
While I agree that carbide is necessary for any serious work in MDF I think you're exaggerating about HSS not lasting a minute.
Last week when setting up a new machine I'm building I pulled out one of the HF HSS 1/4" bits and cut about 30 each of 3/8, 1/2, and 3/4" 1/2 deep circular pockets in 3/4 MDF. Following that I cut about 100 inches of 3/4" profiles (1/4" on each of 3 passes) in the same MDF. These were all test cuts and the edges had some fuzziness but the bit was cutting pretty good for something costing less than $2.50.
To be clear, I'm not suggesting anyone use these for production work but my suggestion was that for learning on a new machine I'd rather break or burn a cheap bit than an expensive one.