What size work is this for??

[riversidedan]

this is a 5/32 x 1/2 rounding cutter , question is what size metal is it intended to cut??

 

[MrWhoopee]

It will round the corner of any stock that needs it. No size limitations.

 

[hman]

As long as you can mount it securely in your tool holder, it should work with just about any size stock, as @MrWhoopee posted. It's just another form tool ... and be alert for chatter, etc. The one you picture looks like it would be best for aluminum. If you want to do lots of steel, I'd suggest a carbide insert roundover bit ... maybe one with a 1/2" shank (for additional strength/stiffness).

 

[MrWhoopee]

As long as you can mount it securely in your tool holder, it should work with just about any size stock, as @MrWhoopee posted. It's just another form tool ... and be alert for chatter, etc. The one you picture looks like it would be best for aluminum. If you want to do lots of steel, I'd suggest a carbide insert roundover bit ... maybe one with a 1/2" shank (for additional strength/stiffness).

I've had very good luck with 1/2" shank router bits. Much cheaper than anything marketed for metal.

 

[graham-xrf]

I've had very good luck with 1/2" shank router bits. Much cheaper than anything marketed for metal.

I have wondered about router bits. At the cutting edge, are there any fundamental differences in clearance angle, and back rake angle, etc ?
That you simply went ahead, and tried a router bit, and it worked OK is very telling.

I get it that many mill tools have spiral flutes, but if router shapes work just fine, how come they are marketed as "woodwork" ?

Searching for some videos on the subject, clearly some folk use wood-style router bits on aluminum. There is some stuff on CNC routers in metal, but unclear what type of cutter is involved. This Old Tony is CNC routing steel, but again, maybe the bit was made for it.

 

[MrWhoopee]

I have wondered about router bits. At the cutting edge, are there any fundamental differences in clearance angle, and back rake angle, etc ?
That you simply went ahead, and tried a router bit, and it worked OK is very telling.

I get it that many mill tools have spiral flutes, but if router shapes work just fine, how come they are marketed as "woodwork" ?

I can't give you anything definitive, but the back rake is zero (face of tool is parallel to axis) and clearance seems to be greater than tools ground for metal. That may just be perception because of the small diameter.

I just needed to round off the inside of that handle and, being a cheap bastard, the difference in price justified the gamble. I've used the cutters like the OP pictured and the router bit actually works better. I've since bought other sizes. At (iirc) $15 ea., it's not a hard decision. They can also be resharpened by the local saw shop, though it may not be worth it.

 

[JimDawson]

I have used carbide and carbide tipped router bits in all materials from wood to 304 SS, all with very good results. There are limitations of course, as they are not designed to cut metal, the cutting geometry is not the best for metal.

You just need to use a little common sense when using non-standard tools. For instance I have some 1/2'', carbide tipped x 2'' cut length straight 2 flute router bits, those are not going to be used for cutting metal. Always use a 1/2'' shank bit where possible, although I have had very good luck with 1/4'' shank bits, but you have to be somewhat careful with them because they are not as rigid as a 1/2'' shank cutter.