Sprial flush trim bits worth the price?

[Ben Davis]

So I'm purchasing some new / more (Whiteside) router bits and I need a flush trim bit. I can get a double fluted 1/2" shank, 2" cutting length flush trim bit for about $20. Alternatively, I can get a 1/2" shank spiral upcut flush trim bit for 300% more.

Are these things so good that they demand the premium? Is burning that much of a problem? I guess you don't have much grain direction problems to consider with the spiral bits, but for 3x the cost, I'll study my wood thank you.

[Peter Quinn]

I have used a whiteside 1/4" spiral flush trim bit in a laminate router to do some trimming that I would not want to try with a straight knife bit. It really does a fantastic job and has a very long life. There are other options in flush trimming, but its not always possible to read where tear out will occur.

Are they worth the price? Yes, I think so. Do you need one and should you pay the price? Harder to answer that question. I have had good luck with standard two flute flush trimmers and even an Amana 3 flute flush trimmer. Some makers even have flush trim bits with a shear angle they claim perform well in tricky grain and cost less than solid carbide. Infinity maybe?

[Lee Hingle]

Ben,
Depends on what you will be trimming as to whether or not they are worth the extra cash. Peter brought up a good point - the shear angle flush trim bits - I'm not sure of Infinity but I know Eagle America sells them because I just used mine the other day - I think it was about $30-$35

Lee

[Ben Davis]

Right now it's just popler. I'll be working with some oak sooner than later though. Nothing exciting or exotic.

[Lee Hingle]

I used the bit to flush trim some red oak (27" diameter hexagon). The end grain cuts were smooth as glass and no tearout. Sounds like this is a better value for you than the spiral.

Lee

[glenn bradley]

I would have to say that if you have not had problems then continue as you are. I use both, or rather all three since I also have shear flush bits. One thing that helped me was the advice to run as large a bit as possible. This excludes any flush spirals I have seen but my 1" Amana flush bit does a really smooth job.

Most in my collection are Woodcraft $5, 1/2", 2 flute jobbers because they're only $5. I have spirals in different sizes for mortising but my flush spirals are 1/4" and I'm unimpressed. The 1/2" spiral (no bearing) used with a guide does a beautiful job. The 1/4" is MLCS and the 1/2" is Whiteside so that could contribute along with the size diff. The 3/8" spiral I use for router dadoing is also one of those things that just couldn't be better; it leaves a crisp, clean path that my 2 flutes do not. My .02.

[Victor Stearns]

I like the sprial flush trim bits. I have several in the 1/2 size and am very happy with the results. I tend now stay away from the straight cutting bits as they seem to have more tear out than the sprials.
Victor