Advantage to 1/2" Shank Router Bits?

[Mike Henderson]

I used to be a 1/2 inch shank bit only worker. But with the new trim routers, I find that I'm using them in a lot of places where I used to use my big routers. Unfortunately they only take 1/4 inch shank bits.

But so far, I haven't had any problems with bits breaking or slipping in the collet. I have a couple of DeWalt cordless routers and those are my go-to for a lot of work.

Most of what I use them for is not heavy work, however: edge profiles, hinge mortise, and a few other things that are too difficult to describe.

Mike

[johnny means]

I've burned through thousands of bits. I've never seen a bit break at the step down, I'm pretty sure I've never seen one machined as to create a stress riser. I've broken a couple of half inch shanks, but dozens of 1/4". 1/4" shanks also tend to spin in the collet. I only use them for trim router type tasks in which they are the only choice.

[Andrew Gibson]

In small diameter bits I would not get hung up on the shank size. Choose the shank that best suits your intended use. If you are likely to want to use the bit in your trim router, go 1/4". You can still use that bit in your larger routers or router table if you have a 1/4" collet. The time to jump to 1/2" shank for me comes around 3/4" cutting diameter. 3/4" hinge mortising bits, 1/2" standard straight bits, round over bits larger than 3/8" or 1/2" radius. This is the gray area where I let application make the call. A good quality bit, if used properly, should wear out before fatigue causes a problem.

[George Yetka]

1/2" less chatter. More rotational mass,more clamping surface, harder to break

[Jim Dwight]

I don't remember any ruined projects from it but my Bosch Colt has had a bit slip some in it's collet. That's why I don't think it is all in the quality of the collet, I think some of the blame is on the shank area being too small. But I still use my Colt and like it. I just have to remember to only take light cuts with it. The motor is stronger than the collet can grip.

On the other side, even my big 3.5 hp Porter Cable router motor in my router table does not slip bits with half inch shanks.

For any cut where you are removing a serious amount of wood, my opinion is you want a half inch shank. For a 1/8 roundover or a small chamfer or something it doesn't matter. But for nearly any dado cut, using a 1/4 inch shank bit is asking for a damaged project.