Forstner bit rotational sped

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Forum topic by lovinmrv posted 03-18-2010 02:40 PM 1619 views 4 times favorited 9 replies Add to Favorites Watch
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103 posts in 2481 days

03-18-2010 02:40 PM

Topic tags/keywords: forstner bit rpm drill speed resource question

Is there an optimal RPM setting for forstner bits and, if so, what is it?

Apologies if this is already covered…I haven’t been able to find it.


-- Life is a sales job.

9 replies so far

View SKFrog16's profile


661 posts in 2622 days

#1 posted 03-18-2010 02:53 PM

lovinmrv, Use this chart. Has all the necessary drill speeds you need.

-- Methods are many,Principles are few.Methods change often,Principles never do.

View Chase's profile


448 posts in 2448 days

#2 posted 03-18-2010 02:59 PM

Fantastic chart UnionLabel, That is getting printed out and possibly laminated for my shop as soon as I get home.

-- Every neighborhood has an eccentric neighbor. I wondered for years "who was ours?" Then I realized it was me.

View DaddyZ's profile


2475 posts in 2462 days

#3 posted 03-18-2010 03:21 PM

Excellent Chart – done saved to favorites !!

-- Pat - Worker of Wood, Collector of Tools, Father of one

View richgreer's profile


4541 posts in 2496 days

#4 posted 03-18-2010 03:31 PM

! agree, the chart is great. I have a similar chart on my wall by my drill press.

The problem is that some drill presses just don’t go slow enough for the big Forstner bits. (I use bits up to 3”).

My advice on drilling large holes is to do it in stages. Clamp the piece securing in place and start with a 1” bit. Then drill again with a 1.5” bit and continue until you have the size you want.

-- Rich, Cedar Rapids, IA - I'm a woodworker. I don't create beauty, I reveal it.

View lovinmrv's profile


103 posts in 2481 days

#5 posted 03-18-2010 03:53 PM

wow…awesome, jocks! Thanks!

-- Life is a sales job.

View PineInTheAsh's profile


404 posts in 2689 days

#6 posted 03-18-2010 04:23 PM

Rich’s “in stages” suggestion (among many eloquent submissions here) is on mark.

Here’s much love to the beautiful gimlet-point bit.

I don’t have a 3” Forstner bit though have played with my 2-1/8” and then jig saw and chisel my way to satisfaction. One day soon am compelled to have a complete Forstner bit of every size they make; the bit design is one of the greatest woodworking inventions ever.

Here’s to the inventive Benjamin Forstner.


View SPalm's profile


5249 posts in 3303 days

#7 posted 03-18-2010 05:40 PM

Just another thought. Heat will kill these things. So turn it slowly, and lower it slowly. In fact, raise it up and let it cool if you are cutting a deep hole.

There are a lot of really cheap sets of these on the market. They may look alike, but there is a reason that the price differences are there.


-- -- I'm no rocket surgeon

View Chris Wright's profile

Chris Wright

540 posts in 2903 days

#8 posted 03-18-2010 06:11 PM

My set of bits have the max speed engraved on the shank. None are show a max speed of over 800 RPM. The larger ones say 650 RPM max. The speed I use on my drill press is in the mid 500’s (if the diagram on the inside of the pully cover is correct).

-- "At its best, life is completely unpredictable." - Christopher Walken

View Sawkerf's profile


1730 posts in 2490 days

#9 posted 03-18-2010 07:11 PM

Drill speed (rpm) is only part of the picture. A lot also depends on the wood you’re working with, the sharpness of the bit, and the feed rate (downward pressure) you’re using.

Use the chart(s) to set your initial speed, but “tweak” it if you need to.

-- Adversity doesn't build reveals it.

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