Wednesday, May 30, 2012

My Favorite Router Bits

I was typing an answer to a comment Jim posted on the OF-1400 demo when I felt a strange déjà-vu so I thought instead of typing it again, I'd make a posting instead :)

The déjà-vu was in answering which router bits I use the most.  Granted, that's just good for comparison if you have a drawer full of them, but if you're starting with an empty drawer, it might make a good start vs some 300-bit variety pack.

There's the motley crew:

There's a cluster of 3 spirals, a cluster of 4 "profiles", and a stack of slot cutters up front.  Lemme go through each.

The spirals:

The front two bits are basically the same except the double bearing on the leftmost bit.  They are 1/4" down-spiral bits from Eagle America.

The one with the double bearing (#120-0412) is used for flushing anything with a tight turn.  The double-bearing has better registration than just one.  I also used this in the MFK-700 for flushing banding nicely until I found an 8mm version (bigger diameter bits avoid 'scalloping' the surface).

The one without the bearings on the right (#106-0452) is for shallow cuts on the surface like for an inlay, mortise lock, etc.  The down-spiral will leave the surface clean although these aren't good for deep grooves since the chips get pushed to the bottom.  In fact that down-spiral is what I used for the French-knot floor inlay as well (not a typical use, I know, but any other bit would shred that cork; down-spiral left it pristine).

The bit in the back is a Whiteside 1/2" compression-spiral double-bearing flush trimming bit.  There are as many adjectives in that bit's name as the average Starbuck's order...  It's not cheap as it is solid-carbide so it'll last long.  Eagle America has an alternative like this one #120-0865 (nearly the same price).  For normal pattern flushing, I use this compression-spiral bit.  The fibers on the top and bottom surfaces are cut towards the middle ("compressed to the middle" ahhh....) so the surfaces have no chip-out or fuzzing.  When following a pattern, I prefer to put the pattern on the bottom of the stock to cut mostly so I can limit how far I extend the router bit; "pattern" bits with the bearing above the cutters on the shank require you to have the whole thing exposed.

For pattern flushing like that, you could just go with a down-spiral with double-bearing and get very nearly the same results (#120-0815 or #120-0835).  Why? Because the pattern at the bottom will back the stock being cut so the down shearing of the bit won't chip-out.  As you can see, though, the price of the 1/2" down-spiral is about the same as the compression anyway.

Using a router on a guide rail, I can also use the compression spiral to cut a very clean edge.  Rough cut the edge with whatever you like (bandsaw, rip blade, frenzied beaver).  Lay the guide rail so the bit cuts your final edge.  The bearings will be below the board in this case and not used.  Make sure the small bit of "up-spiral" at the end of the bit is against the bottom of the stock and the cut will come out fantastic even with curly grain.

As an aside, the CNC industry uses compression-spirals a lot for cutting stock cleanly like that.

Last bit that I neglected to put in the photo is a 3/8" up-spiral.  I use it for mortise cutting.  I use 3/8" because my mortise will be at least that wide; for wider mortises, I prefer a second pass anyway.  The reason mine isn't in the picture is it was a HSS bit that got way over-used and is all discolored :)  I'll be getting a new carbide version.  For spirals without bearings, I now always look at Vortex Tool first; great bits.  This three-flute will be the replacement: #1860 (or the cheaper two-flute #1260)  They make bits for the CNC industry (hence no bearings); these are competitively priced, but made to much higher standards than other spirals.  Have some fun browsing their bits; dovetail spirals? yeah, they have that, too.

Addendum: someone asked about plywood bits... :-/  plywood isn't a specific thickness so while those bits get closer to the correct size, they never are.  You'll have a gap or too tight a fit.  That's why I do dados/grooves in two passes with a smaller bit and use the Bridge City KM-1 to exactly size the dado.  Even if "plywood bits" were the correct size, straight flutes in plywood make a messy splintered top; the compression spiral is the solution to that.

Enough about spirals :)

The next group, "profile" bits:

The blue bit is a 45º chamfer bit.  Usually I'll use a hand plane to put a chamfer on something because the small variances add character.  On a large chamfer, I want a bit.  Another use for this bit isn't so obvious: jewelry boxes.  For a small box like that, cutting thin stock on a 45º bevel for mitered corners can be messy with chipout.  Instead, I put the squared stock in a coping sled (discussed later) and apply a perfect 45º bevel on the edge with the bit.  Just back the board in the sled to avoid splintering on the exit cut.

45º camfer bits can be had about anywhere.  The blue one is from Rockler and one of my first purchases. Since I have the Eagle America site open for links, here's theirs: #152-0645; they even give a table of degrees for such boxes.

The green bit to the far right is a dish carving bit.  That's a Woodcraft bit.  It basically has a flat bottom with vertical cutting sides and a radius.  Think of it as a cambered plane blade for your router.  As you move around (paying attention not to climb-cut) flattening a recess, the radius keeps you from getting "router tracks" that are a pain in the butt to sand out; ask me how I know...  that was the reason for buying this bit.  I got a couple of those green ones on a clearance sale; good to do since you tend to hog out a good deal.  But you can sharpen them up... more on that later.  It seems Woodcraft no longer sells the greens and have switched to Freud ("reds" :) so here is the equivalent bit Freud Dish Carving bit.  Oh, if you suspend a router on a track to 'joint' a board below it, this is the bit you want: the radius eliminates most of the router tracks and also makes moving the router easier than with a straight/spiral.

Big green bit in the back is a tabletop edge bit.  It has a second radius on it, but I don't use that often; typically I just use the swooping profile up top near the bearing.  Makes for a nice edge on the underside.  I cannot find this bit online from Woodcraft (Woodriver brand) or others.  It shouldn't have been in the picture; I use it often for parts of the profile, but I wouldn't say it's super handy for everybody.

The grey Whiteside bit in the back to the left is the Charles-Neil signature molding bit.  Over the years, he used a huge multi-profile molding bit, but only used one portion of it for nearly all his projects, so he refined that profile and had a custom bit made.  He gets a run of them made from time to time so if they aren't available, sign up for his email list and you'll find out when a run is being made (or send them mail so they know there's a demand!).  I don't put profiles on a lot of projects, but usually what I want is on this bit somewhere.  Whiteside bits are excellent.  As of this writing, he has 5 left.  No pressure :)  First consider if you plan on using profiles often; these are decorative ones.  Traditional furniture has lots of molding.

The last bits I showed in the first family photo is a screw with a bunch of slot cutters on it.  I bought this set from Eagle America: #199-4615.  That's the 4-wing set; they cut very smoothly, you can stack them for different slot sizes.  I don't use them a lot, but they seem to be more of a "only good thing to use here is a slot cutter"... there are times when they're the perfect solution, like routing a groove in thin stock you don't want to stand up on the router table or, more scary, table saw.

After awhile, you'll get a decent number of bits with bearings.  Getting a bearing kit like this isn't a bad idea; note that this kit is geared towards slot cutters.  I swap out bearings to change how deep a profile or rabbet goes; this is a good-to-have for later when you notice a lot of bearings on your bits.  Bookmark this page: Bearings and look at the bottom for related kits; all of those kits fit different needs; when you need a different bearing, go to that page and you'll find it after a minute or three.

So I mentioned a coping sled.  I use this Woodpecker's coping sled and really like it.  I like the easy adjustments, the quick ability to remove parts of it if you need more capacity, all the excellent hold-downs, lots of T-track for your own additions/jigs, and the best part: it rides against the fence, not in a "miter slot".  Since it rides the fence, you can do your usual fence adjustments on successive passes instead of readjusting the stock in the sled.  You can also use this against a start pin when using the sled to deal with small parts (oh, most "small parts" holders I've seen and tried were really lame; judge it in person before you buy one).  The only complaint I have with this sled? The top plastic that rides against the fence rides really close to a T-slot on my Woodpecker's fence :-/  Since I use a sacrificial fence on the fence anyway, it isn't normally an issue.

Last tidbit... get a bit cleaner and clean them; makes a big difference.  I also have a set of diamond sharpeners by Eze-Lap (here's a DMT equivalent)  Use these on the flat part of a bit's cutting edge to touch it up (never on the outside bevel).

Others that get used from time to time are bearing-guided rabbetting bits (I have two: one for 1/2" deep, and the other I swapped the bearing so it's a 3/8" deep rabbet).

Round-overs?  They seem like you'd use them a lot, huh... I use the 1/4" radius roundover for making shop-made oversized Domino tenons.  Everything else gets a hand-plane or rasp/file treatment.

Okay, sorry, that was longer than anticipated!


  • Unknown said...


    Thanks for the lightning fast response to my question and the great post-- VERY helpful and just what I needed. I have one follow-up question-- I tend to cut lots of dados for plywood and would love to do this on the router rather than the tablesaw to avoid frequent blade changes. What bit would you recommend for this application? Could I use the compression spiral or would I be better off with an upcutting spiral (maybe 3/8ths for two passes for the slightly undersized 3/4" plywood I usually use). Or would I be better off with one of the "plywood" bits that are specifically sized and would only require one pass?

    As always, thanks for your great advice

  • Paul-Marcel St-Onge said...

    Hi, Unknown (previously known as Jim :)

    I amended the posting to put yet-another paragraph in about plywood bits. At the end of the spirals section. In a nutshell, a 3/8" compression spiral and a Bridge City KM-1 will give you very clean dados that are exactly sized; better, the KM-1 doesn't care if you are sizing ply or hardwood so it's more efficient, too.

    To me those plywood bits are a gimmick.

  • bob said...

    Hey Paul- Marcel, Vortex is a Wisconsin Company! Watch out, you keep buying here, you may move here. Much better wood then the desert too. bob

  • Paul-Marcel St-Onge said...

    And more important than all that, Bob... Vortex's home page lets you see it in Portugese. I'm gonna assume they have Capoeira breaks and "visually stimulating" Mardi Gras office parties. What's not to like? Hey, you guys have ice rinks up there, right? :)

  • Qwas said...

    I love my Eze Lap. I use it all the time for lathe bits (metal working lathe). The fine and super fine should be the only ones they need for router bits but I can see where a medium could be useful for chisels that went too long between sharpenings.

    Nice blog. I was one of those suckers that bought a 50 bit kit only to discover later that I will use 4 or 5 bits out of the kit. At least it is a nice looking case.

  • ChrisHasFlair said...


    I've found that 3-flute bits cut noticeably more slowly than 2-flute bits. For much of my routing (especially mortising), I prefer 2-flute bits for their speed.


  • Anonymous said...

    I see one bit didn’t make the cut as one of your favorites.

    Thanks, Dean

  • Paddywack said...

    I am looking for your review on the Ceramic Guides from Laguna and the Resaw King blade, can you point me in the right direction to read it please,
    Like your Festool videos.
    Regards from the UK,
    Michael Redmond.

  • Paul-Marcel St-Onge said...

    Thanks, Michael,

    The review is one of the 3 videos posted here: Review of the Laguna Italian-Made LT-18.

  • OyDeals said...

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