I am having the hardest time finding a 1/4" shank, 1/4" radius (1/2" diameter), bullnose router bit with a bearing guide. It's almost as if there is some mechanical reason why this bit can't exist?! I see this bit with 1/2" shanks in various places or a 1/4" shank but without the bearing, but nothing is like what I described.

So this… but with a 1/4" shank: bit

If there is a mechanical reason why I can't find this, please explain (like, "routing bullnose puts too much pressure on the shank...", or something). I would be interested to know.

  • (I know this is very old.) You could use a 1/4" round over bit and a straight edge clamped on the board. A 1/4" round over from each side would end up with a 1/2" diameter bullnose. It wouldn't be as convenient as it would to make it in one pass, but sometimes, you've got to work with what's available.
    – FreeMan
    Commented Sep 27, 2021 at 0:04

2 Answers 2


There is no reason I know of. In fact I have one in my shop. Check out here for one source. Their image does not show the guide bearing. My bit has a screw hole to accept standard bearings and you can call them to confirm the hole is still there. I'm also sure they sell the bearings in a variety of diameters. Good Luck.

  • Thanks. I didn't know you could add a bearing. Is that standard for router bits? How does it work? Anyway, I'd prefer to get one that's already complete, but this is a good option.
    – Sam
    Commented Jul 24, 2016 at 3:04
  • Bearing holes are certainly not standard for bits, but you might get lucky here and there. Commented Jul 24, 2016 at 14:13
  • I sent a support email to Grizzly asking to confirm whether that bit is compatible with a bearing... will update when I receive a response!
    – Sam
    Commented Jul 24, 2016 at 14:26
  • A response from Grizzly: "Unfortunately, there are no provisions for adding a guide bearing to this bull nose router bit." And there you have it. Once again, I'm just shocked that this product seems impossible to find?!
    – Sam
    Commented Jul 26, 2016 at 19:04
  • Well that sucks! Sorry about that. My Grizzly bit does have it.probably a decade old though.
    – Ashlar
    Commented Jul 26, 2016 at 21:25

This one: http://www.amanatool.com/products/router-bits/profiling-router-bits/bullnose-router-bits/51547-carbide-tipped-bullnose-1-4-radius-x-1-dia-x-1-x-1-4-inch-shank.html#!prettyPhoto appears to be tapped for a bearing, but you'd want to verify that they haven't changed them.

Alternately, you could use an edge guide and avoid the whole bearing thing entirely.

  • Thanks. I don't see one with a 1/4" shank with a 1/4" radius. Am I just blind? This is the problem I'm having! Ha! It's like there's some fundamental reason why this bit can't exist!
    – Sam
    Commented Jul 24, 2016 at 14:24
  • Ooops! My reading comprehension isn't great, apparently. Answer edited. Commented Jul 24, 2016 at 14:51

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