A 3" brazed tip carbide face mill? I'd toss it and get a good carbide insert mill if I were you. Today's carbide inserts can be tough as nails (much tougher, actually) and are easy to use on home shop machines.
My dad's shop has (for now) a 1960 Bridgeport with the step pulley 1HP 3-phase drive. While I can't bury the 3" 45º 6-insert cutter I have in any material, the 2-1/2" 4-insert cutter flows chips pretty good in almost anything. I have tough, yet fairly sharp inserts that make any job easy as pie. There are many good choices out there. I can't understand why "carbide is verboten" any more than you would understand if I said "High speed steel has no use in the shop." Neither should be true, ever. The 316 rpm can be good for a 3" face mill if it has at least a little power. Any tool, whether HSS or carbide, can snap if the spindle stops in mid-cut while the feed is still going.
Perhaps time in a home shop isn't equated to dollars made like a commercial shop. Still, time spent fixing broken stuff and getting frustrated when you should just be getting a job done is not making any martyrs or heroes. We all have a learning curve and there can be some quantum leaps made with tools that work.
As for 3-flute vs. 2-flute or 4-flute end mills, I use them all. They all have their best applications. In HSS end mills a 2-flute is nice for small diameters (under 1/8") because it can be stronger. Also good in larger diameters for aluminum. I like 3-flute anytime I'm slotting, as they offer the best balance between core strength and chip evacuation. The 3-flute are also the best choice when you need a center-cutting end mill for plunging. Four flute end mills are best for steels and stainless steels, primarily for side cutting (rather than true end milling.) As material hardness goes up, so should the helix angle. Hook, clearance angles, secondary lands, grind quality and raw material quality all play a part in how well your HSS or solid carbide end mill will perform. There are many grades of HSS, and it seems only the very best makers will state the type.
I have some beautiful HSS-PM (powdered metal) 3-flute TiAln-coated end mills for aluminum from Cleveland Tool, and they just kick butt. Those are the ones from right to left, a 3/4" and two 5/8". I have a few solid carbide that I wouldn't be without, and many in between. Buy quality tools and treat them as such. You'll be rewarded with good parts and fun making them.
![[Image: IMG_0993-r.jpg]](http://img.photobucket.com/albums/v466/kenm10759/Dads%20shop/IMG_0993-r.jpg)
My dad's shop has (for now) a 1960 Bridgeport with the step pulley 1HP 3-phase drive. While I can't bury the 3" 45º 6-insert cutter I have in any material, the 2-1/2" 4-insert cutter flows chips pretty good in almost anything. I have tough, yet fairly sharp inserts that make any job easy as pie. There are many good choices out there. I can't understand why "carbide is verboten" any more than you would understand if I said "High speed steel has no use in the shop." Neither should be true, ever. The 316 rpm can be good for a 3" face mill if it has at least a little power. Any tool, whether HSS or carbide, can snap if the spindle stops in mid-cut while the feed is still going.
Perhaps time in a home shop isn't equated to dollars made like a commercial shop. Still, time spent fixing broken stuff and getting frustrated when you should just be getting a job done is not making any martyrs or heroes. We all have a learning curve and there can be some quantum leaps made with tools that work.
As for 3-flute vs. 2-flute or 4-flute end mills, I use them all. They all have their best applications. In HSS end mills a 2-flute is nice for small diameters (under 1/8") because it can be stronger. Also good in larger diameters for aluminum. I like 3-flute anytime I'm slotting, as they offer the best balance between core strength and chip evacuation. The 3-flute are also the best choice when you need a center-cutting end mill for plunging. Four flute end mills are best for steels and stainless steels, primarily for side cutting (rather than true end milling.) As material hardness goes up, so should the helix angle. Hook, clearance angles, secondary lands, grind quality and raw material quality all play a part in how well your HSS or solid carbide end mill will perform. There are many grades of HSS, and it seems only the very best makers will state the type.
I have some beautiful HSS-PM (powdered metal) 3-flute TiAln-coated end mills for aluminum from Cleveland Tool, and they just kick butt. Those are the ones from right to left, a 3/4" and two 5/8". I have a few solid carbide that I wouldn't be without, and many in between. Buy quality tools and treat them as such. You'll be rewarded with good parts and fun making them.