"Just because someone calls/sells a bit as a "forstner", does not make
it so." I agree, but then I am so naive. If you bother re-reading my
post, however, you'll see that the companies I mentioned were making
Forstner bits well over 100 years ago, under license from Benjamin
Forstner - the inventor. That's not a Forstner bit?
Someone else has already posted a link to Benjamin Forstner's patent -
# 115148, dated August 15, 1874. Rather than make you search for it,
though, here is a quote from it:
"The circular band serves to guide the bit accurately in its movement,
and also give the hole that is bored a smooth and perfect finish. By
its employment the gimlet-point may be dispensed with, and as the
cutting lips do not project beyond its horizontal plane, it follows
that the wood is not cut beyond the line operated upon by the circular
cutting-edge of the band."
And that, Swingman, is an inarguable FACT, with which you must deal.
Takes a man to say that, Swingman. Pax.
I'll admit myself that I didn't know of Ben Forstner's later idea of a
center point. I've never seen a Forstner with one large enough to
keep it on center. I have sawtooth bits with large center points, but
I wouldn't call those Forstners.
Of the Forstners that I have that do have the center points, they are
handy in visually centering a spinning bit on a mark, but that's about
The link is to an Feb 26 1886 patent which Benjamin Forstner clearly
felt was an improvement and DOES include a cutting-point. A quote is
under. So you are both right
In the manufacture of in improved auger the slots b are formed by
milling, thus facilitating the manufacture and lessening the expense
which necessarily attended the manufacture of the bit made under my
formerpatent. 1. In an auger, a circular peripheral cutting-edge formed
of two parts, a a', each provided with a cutting-edge, e, inclined slots
d, formed in opposite sides of the cutter, cutting-lips b,formed along
the inclined slots, and a central cutting-point, e, joining the
cutting-lips b, substantially as herein specified
-- >replace spamblock with my family name to e-mail me >Pics at http://www.meekings.net/diving/index.shtml
I'm quite certain I'm talking about a Forstner bit, and even with the
center point, I still had skate issues.
These are the ones I was using, straight from the Rockler store in Sandy
They have they point. They are forstner bits.
Yet, I had skate issues when the main body dug in, all probably due to
RPM speed. My Dewalt doesn't have a lot of inbetween (14.4V 1/2" chuck,
older model. It's either not enough, or too much.)
That was my experience. I'll stick to using them in a drill press.. OR
using them in a different drill.
If they skate on you out of the box, what you're experiencing is mostly the
result of poor quality. Not surprising as Rockler's hardware quality seems
to have suffered since the advent of importing.
Next time you need a good Forstner of modern design (with the center spur),
try the "Bormax" or "Famag" brands (you can now get both from WoodCraft):
The "Bormax" are a bit pricier (no pun intended) but have served me and I've
used a ton of forstner bits, particularly the 35mm variety for drilling
cabinet door hinges. The one I have now has drilled a couple of hundred
cabinet doors and will still cut you when handling it.
Famag was best of breed in a fairly recent FWW review.
Cool, appreciate that info. I don't often find myself needing forstners
(I'm just getting back into the swing of things, as it were), but the
next time I need to do a bunch I'll invest in a couple of those.
Skating seems to be a probelm with many brands of cheap Forstner bits.
Oddly enough, this is one area where price really does seem to follow
quality. Connecticut Valley, Famag and a couple of others have pretty
much traditional patterns, but don't skate--if they're kept sharp.
Some who wants to pay 30 or 40 bucks for a 16 bit set, should expect
poor to fair (if they're lucky) out-of-the-box performance that
improves with sharpening, but never equals, or even comes close, to
the performance of the high end bits.
Famag is new to me, but ConVaCo bits have been around since I started
messing with wood back in the early '50s. Jeez. No wonder the kids
seem to be aging.
I have a similar cheap set. For the sizes that you only drill with one or
three hoes a year, they are good and it is handy to have those sizes around
"just in case". But the 3/8" and 3/4" that I use a lot have long been
replaced with better ones that hold up longer.
Um... Heh.. I made a booboo blunder. :)
Was working on something else this morning and had reason to drill a few
holes. Chucked a bit in the dewalt and commenced drilling... and
realized it was drilling quite well - and fast.
Turns out I had somehow changed the top speed switch from "1" to "2" and
didn't notice. Hmm, I wonder. Fetched the aforementioned forstner bit,
chucked it up, grabbed my scrap piece, and set the switch to "1".
Guess what? More speed control, and I was able to drill in quite well
and with only a little effort I was halfway through the scrap. More
importantly - no skating!
Morale of the story: user error on my part. So for precision holes
freehand, I'll use a forstner in the drill (spade bits otherwise), but
still prefer the drill press for 'em.
(typing with horked thumb in splint is fun!)
I may be over-simplifying but I think the center point is there to provide a
small reference pilot for true center if you need to extend a smaller
diameter bit through for a bolt or dowel; at least that is what I have used
it for over the last 40 years or so.
As a kid and while going to colege, I worked in a production shop that did a
lot of turnings, they used forster bits to set up the ends of the stock for
the tail piece.
I have always planned machining operations around that when working with
wood. Not so often but also with plastics.
I think that a couple of the operations even used modified bits to trip the
top of legs outer diameter to uniform sizes so they would fit into the
corresponding hole that was bored to receive it.
BTW - new here since Verizon took away alt binaries pictures woodworking
Thanks for having me
Oh, I most definitely am. The Forstners I use are almost all by
Connecticut Valley, BGI or PM - companies that have been making them
for well over 100 years. Machine shanks and bit brace shanks. Some
have small points that extend below the rim, some don't. On none of
them does the center point extend more than about 1/16" below the
rim. Of those that don't, some never did - it's not a re-sharpening
mistake. The Forstner bits are meant to be guided by their rims, not
their center points.
I even checked a couple of really big Forstners I have - 2-5/8" and
2-3/4", 3/4" shanks, about a foot long. Conn Valley, but they don't
show them in their product list anymore. Original factory grinds.
Each has a central point, but it's flat-topped and about 1/4" wide -
it's certainly not intended to guide the bit.
With the brace bits, one trick is to turn them backward at first to
get the rim to dig in slightly before you start to cut.
I've got no idea what was in Benjamin Forstner's original patents -
all I know is that the companies that have been making them from the
beginning have been making them without center points large enough to
significantly guide them. They do help in getting them on the center
mark, but that's about it. If you had a gimlet point, you wouldn't
get a flat-bottomed hole, would you?
Yes, exactly right on both counts. I ment carbide, and yes, my problem
was keeping the bit from skating around.
As I said originally, I stopped after a minute. However, once I got
past the 1/8th inch mark I had enough of a "go" to where I could have
continued on, since the bit was sharp enough. I didn't though, since I
was already "job done" on the drill press.
I bought some High Speed Steel wood bits from an online vendor of some
repute (the name of which escapes me) and was impressed when removing
the plastic coating each tip had been dipped in as I sliced my finger
on the bit as I removed the coating.
They worked wonders in the wood, too!
I bought HFT "Forstner" bits and another set from one of those mobile
vendor "Tool Sales" and one from Bosch (at Lowes). The Bosch was more
expensive (35mm?) than was the first set of six from HFT and the
larger set (to 2.5") from the mobile vendor.
I use a drill press - mostly, But I have used them in "electric
drills" from time to time with decent results - certainly nothing to
Having said that, I wonder if anyone has any experience with a HSS set
from Hartville Tools, or another vendor as I would love to buy a set
as sharp as the bits first referenced, above, in the Forstner style.
PS, the Irwin Auger Bits with Three (3) flutes are a joy to use. In my
14.4VDC Sears drill *shorter than my 19.2VDC model, with less torque/
power" I was easily able to "punch" holes through the floor joits to
run my wiring "out of the way." They have that screw starter point
and pull themselves through leaving a nice clean hole, If you hit a
nail enroute, however, they suffer significantly!
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.