View Full Version : Single flute router bits - Anyone use them?

Jim Shaper
05-29-2010, 01:06 PM

I've got a part that needs a .110 wide slot in it that's a couple linear feet long (neoprene gasket seat) and just under .200 deep (ugh!). The material is aluminum, and my coolant system isn't assembled currently (still need to get the carbon dust out of the sump/pump and get the enclosure rebuilt).

I've done a few parts with my other micro carbide bits, but I'm not too keen on pushing the feed rates with those and the cycle times are accordingly atrocious. They're also 4fl, so the chip load can't be too high or it'll plug them and we know what that does.

I've seen the single flute bits in enco and such, but have never seen or heard of anyone using them. Are they any good? Can I run them dry without edge build-up/welding?

I want to make a few of these parts to pay for the enclosure repairs, so getting the coolant system running isn't going to happen first.

05-29-2010, 01:20 PM
If you are worryed about buildup, how about considering just dribbleing some coolant oil over the workpeice at the start of the job? like rapidtap or similar.
as the cutter works it way through the little drips on the surface it will coat the cutter, while only causing very minimal 'splatter' and mess. (Praticaly none)

Jim Shaper
05-29-2010, 01:33 PM
I've been running them with a puddle of cutting oil, but the slurry that results is probably just as bad for the edge life as being dry would be. I'm also going through a lot of oil since I blow or vacuum the chips out for successive passes. I'd like something that won't weld so I can use an air blast instead.

tyrone shewlaces
05-29-2010, 02:06 PM
Blast air!
If you don't have a compressor or it's too small, then maybe not an option.
But just a healthy stream of air from a blow gun will do about what coolant does. Sometimes it's preferred. It do get messy sending chips in a pretty wide radius, but not that bad. In a pinch a few pieces of cardboard will take care of that.
Clamp it to point right at the work and let 'er rip.

But no, I don't have an answer on the single flute bits. I'm guessing they would be as good as the other router bits and end mills they carry. Not great in metal, but might work OK for a one-off job. Actually, single flute at HF might be better than multiple flute since there isn't a concentricity issue.

Jim Shaper
05-29-2010, 02:15 PM
These are 6061 parts, so it's not overly gummy, but running too much chip load causes excessive heat in the tool and then the breakage sets in. And that's with real cutters that don't require a loupe to check for edge condition. :eek:

I don't have the gonads to experiment with high speed machining (extract the heat with the chip by running super fast through it) when the cutters are 25 bucks a pop.

I've got plenty of air, but like I said, I've never used this style cutter, so I don't know how well they work.

John Stevenson
05-29-2010, 02:17 PM
I have been using single flute woodworking router cutters in alloy with good success, although it depends on the alloy.

Some of the thin sheet parts I've been cutting are rubbish as the alloy is 99% but since I sourced some thin sheet with a decent copper content they cut well.

Us a old spray gun turned right down with paraffin / kerosene in it to lube and clear away. You don't need much at all.

[edit] just seen you post about 6061 so you should have no problem with that, single lip is better in soft materials as it leaves more gap for the chip to go


05-29-2010, 02:54 PM
If you use a shop vac instead of air blast the chips don't spread as far......

Rich Carlstedt
05-29-2010, 10:36 PM
Don't use liquid coolant
Use candle wax
Rub the part and the cutter with a old candle or parrafin block.
Makes vacuming the chips a breeze and stops edge buildup.
The wax sticks to the chips as a solid
Single flute cutters work well in Aluminum as they have huge chip relief.
The danger is that the work must be rigidly contained.
You run into vibration from the single flute cutting on one portion of
the work piece when slotting.
They give great slot width control . I prefer them for precise double passes
on a slot

Jim Shaper
05-29-2010, 11:05 PM
So how do you deal with subsequent passes with the wax lube method?

Any way you look at it, this is 2+ passes for the needed depth.

Rigidity isn't much of a concern with how I designed the fixture, I simply need to get the cycle times down closer to where they should be. It's a 3/4" thick slab of bar stock taking a slot .2" deep.

05-29-2010, 11:13 PM
Is it possible cut the slot with a 3/32" slitting saw and then go back in and open it up to .110". In other words get a blade that you can mount in your table saw.

Jim Shaper
05-29-2010, 11:56 PM
The slots are contours with 1/2" radii on the corners of a 1.4x1.3" box. Slitting saw ain't gonna do it.