"Jim Wilkins" wrote in message
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"Howard Beel" wrote in message
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"Jim Wilkins" wrote in message
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"Howard Beel" wrote in message
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"Jon Elson" wrote in message
news Howard Beel wrote:


I have found that most slitting saws have some runout and usually
need
a touch up when mounted in the arbor. For some reason there always
seem to be a few teeth that are higher than the rest. Some of the
blades
i indicated were 15 thou out of round and i sent them back to the
vendor.
After mounting the saw in the mill i indicate it and mark the high
teeth
then use a dumore tool post grinder to knock down the high teeth.
I like the peterson expanding flush mount arbors and robbjack arbors.
Yes, I can certainly hear the runout as a zing-zing-zing as the
spindle
rotates. It doesn't seem to hurt the operation or affect surface
finish
much in the groove. So, I just live with it.

My guess is these things are punched out of blanks, rather than
machined and
sharpened on an arbor.

Jon

It would be intresting to how the saws are made. Since they are made of
HSS
i don't think they are stampings. Maybe the hardened blanks are stacked
and
ground on a specialized cnc grinder, grind a bunch of the same size
saws all
at once?

Best Regards
Tom.

I turned and milled the shank end of a 3/8" HSS drill bit into a 1/4"
hex with retention groove to snap and lock into an extension shaft. It
cut easily with HSS tooling.
-jsw


All the HSS drills i have run into have soft shanks. Only the flutes are
HSS.
My collection of big drills were originaly 4 and 5 MT that i purchase
cheap
because there is no hobby market for them. Generaly you can buy them at
industrial auctions for scrap prices. Just turn down the shanks to size
you
need. I use a collet chuck to hold them so the shanks don't mungged up.

Best Regards
Tom.

I understood that the drills are HSS all over, but the shank remains
annealed for better grip.
http://www.zianet.com/ebear/metal/heattreat5.html
"mica", not "mice".

The MT2 tailstock on my lathe and B&S 7 spindle on my mill limit drill bit
size to around 3/4" for heavy cuts, 1" by going slowly. I cut larger holes
by boring or with a hole saw.
-jsw

If you take a taper shank drill and test the shank with a spectrascope
you will see it is not HSS. I know this for a fact. Back in the 1970's
i was in the bussines of buying and selling alloys. Back then M2,M3
HSS would fetch around $3.00 per pound. We always cut the shank
off taper shank drills to maximize profits.

The largest drill i have is 2.75". Don't use hole saws anymore, switched
over to annular cutters. For boring i like the kennametal twin bore tooling,
no more tapering concerns and they use cheap carbide inserts. For big
holes a treapaning tool is the way i go.

Best Regards
Tom.






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