Flat or precision ground?

When ordering metal stock online what is the difference of flat ground stock and precision ground stock? Does precision mean a smoother
surface or something else?
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snipped-for-privacy@yahoo.com wrote:

It means what it says. Its precision dimensions. Flat ground is just pretty to look at, tolerances +/- 0.005 kind of thing. Precision ground is +/-0.0005 kind of thing.
Steve

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What Steve said, but recently bought a piece of flat ground 52100 from AdmiralSteel.com and instead of 1/8" it's .116" on on end and .118" on the other. Turns out good for me that it's that way actually. ;)
The grinding marks on the 52100 are in the form of swirls BTW.
The thickness is very important to me since I mess with re-placing pocket knife blades and springs and certain odd-ball sizes are needed. I figure I can flat-file about as good as most but somehow even using a micrometer etc the "homemade thickness" just doesn't feel right after the pocket knife is all together. :/
CRA 1095 has a smoother finish than precision-ground O1 IME.
But I've gotten some 3/32" 1095 that's as low as .090", which again worked out great for me. :)
CRA (cold rolled annealed) has a nicer finish than the HR (hot rolled) and is what you'll want if any of the finished knife is going to have some of the original surface left showing.
I recently got some hot rolled annealed 1095 and for me, and my dislike of polished knife blades;) it's going to work out great.
All I -really- care about is-> edge taking and edge holding, ok?
Right here on this NG is where I learned so much about circular saw blade steel. -0186 or "8670-modified"- That stuff has turned out to be great stuff! ...and talk about some odd-ball thicknesses. ;)
Done made quite a bit of use of both those attributes already too. :)
One example is an old clunker 4 bladed scout-knife with a missing spring, turned it into a 3 bladed "cattle knife".
Cattle knife = early 1870's Stockman - early 1890's
"murkin" utility knife is a cross between the you're-a-peein utility and the murkin cattle knife = 1900 and adopted by the Boy Scouts in 1911. -paraphrased from Levine's Guide
So a "scout knife" is like, new-fangled junk, or something. ;)
http://www.panix.com/~alvinj/Pal.jpg
(didn't end up using all that's shown) (I made the butt-spring for the original master blade from 1095)
http://www.panix.com/~alvinj/Pal-F1.jpg
(only replaced those two blades and they are .102" 8670-M) (original double-ended-spring was made by Remington and is .100")
http://www.panix.com/~alvinj/Pal-F2.jpg
(original Remington black jigged phenolic plastic handle slabs) (no brass or nickel-silver in that old 50's knife so I used baling wire and W1 drill rod for pins)
http://www.panix.com/~alvinj/Pal-F4.jpg
(the original blade that I didn't re-heat-treat which leads to a whole nuther thread ;)
Alvin in AZ (knife knut)
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