I guess you have to select a "Prefix" since my first submission has gone missing.
I use diamond paddles, a small stone cone and needle files to sharpen HCS Forstner bits. The stone and diamond paddles work OK for my HSS Forstner and sawtooth bits but, I need something to handle the saw-tooth and smaller flat areas. My current needle files slide right off. I bought some EZ-Lap diamond needle files but, the HSS rubbed the diamonds right off the substrate. I have had similar problems with Trend's diamond products. My DMT diamond products work very well but, they do not offer a needle file like product.
My question; Does anyone have a recommendation for a needle file-like product that will cut HSS? As mentioned, my problem area is the small sawtooth faces and such.