# bit speed



## rjb (Feb 22, 2007)

There are several postings here about bit speed.I know when a bit sounds right to acomplish the job safely but am wondering if there is a chart from router manufacturers giving the speed of the router rpm to how fast a bit of a certain size is actyally spinning?


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## Mike (Nov 22, 2004)

This link will show you how to figure out bit speed.
http://www.newwoodworker.com/rtrbitspds.html


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## rjb (Feb 22, 2007)

Thanks Mike was thinking more like say from hitachi as thats the router I use right now and the speed knob is numbered sequchally not showing actual bit speed thats why i listen very carefully to the sound


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## kp91 (Sep 10, 2004)

RJB,

The speeds are guidelines (kind of like the speed limit to most of us....) so just take your speed range and break it up into the number of marks on your switch. If you round a little here and there, it isn't going to make too much of a difference in the long run. You WILL know by ear if you are spinning a bit too fast.

For example- 8000 rpm to 24000 rpm router with 6 marks on dial would break down to roughly 3000 rpm per mark, or..

1 = 8000 
2 = 11000 
3 = 14000
4 = 17000
5 = 20000
6 = 23000

Hope this helps!


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## Qstick (Feb 22, 2007)

A bit (no pun intended) off topic - but what does a bit going to fast sound like? 

Zach


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## bobj3 (Jan 17, 2006)

Something you don't want to get next to.    is a good rule of thumb. 
Router bits have a voice, so to speak ,it will take some time b/4 you can hear it.

Bj


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## rjb (Feb 22, 2007)

thanks kp91 that makes sense even division on the marks. ure right bob the tone changes dramaticly with each speed change. Very noticable on a larger bit.


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