# 1/2" Baltic Birch.......Wait, not so fast.



## cranesgonewild (Jun 9, 2010)

I was in the local big box store to buy some 1/2" baltic birch plywood a few months ago. I've learned from my past experiences to carry a tape measure on me when I buy wood. I bought a piece that was 2' x 4' x 1/2". The UPC on the plywood said 1/2", but the label on the shelf said 11.5mm (which is about 1/16" shy of 1/2"). I measured it, and sure enough, it was 7/16"(11.5mm) thick.

I want to know. Is this a Canadian thing, seeing that I'm here in Canada and we're suppose to go by the metric system, which I don't. Is it the same in the States?

If so, why is it that plywood companies do this? Why can't they just leave it at 1/2" thick? Is it the cost, because I'll pay for the extra 1/16". It really screws me up sometimes when I'm going by a certain set of plans, and I have to change the numbers because of the thickness. 
I ran into this problem again in my latest project when I made the Kreg Jig Workcenter. I went with MDF for the stock supports for the top of my lid because I needed 1" thickness so it would be level with my Kreg jig. I could have used 1/8" wood veneer and sandwiched it between the two pieces of baltic birch, but I didn't want to go that far.
The plans in magazines such as WOOD and WoodSmith call for 1/2" sometimes, so it must still exist.

So my question is, 
Is it the same in the states? 
And is there any such thing as 1/2" baltic birch anymore?


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## Karson (May 9, 2006)

I think this is lind of like selling Ice Cream in 1.5 or 1.75 quarts. instead of 1/2 gallon. It to raise the price by giving a smaller package.

The plywood mfgs have just made them thinner to get a higher price for their materials. They may reply because it was to standardize on a metric scale. But they didn't reduct the price to do


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## Petewood (May 14, 2010)

Actually, it's because of the unavoidable inconsistencies in the manufacture of plywood. All plywoods (lumber core, MDF core and plycore) are made using heat and glue. Wood being what it is, this causes lots of variation (as much as .022" on lumber and ply core sheets) in the finished thickness, one corner to another on the same sheet. They can't just sand it flat, because veneers can be as thin as 1/100th" on the cheap stuff, and still only 1/40th" on the good stuff.
The reasoning for its finished thickness is that the finished sheet can be a bit thinner than nominal (to say, fit into a slot that you cut for it) but not thicker.


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## Dark_Lightning (Nov 20, 2009)

I just went and measured an old piece I bought in 1997, and it's .251" +/- a couple thou, all four corners. The sheets I bought earlier this year are .223". I call cheapness on the manufacturers. I bought both from reputable suppliers, so that's not the issue.

Based on this, I'm not buying the variable thickness story. Manufacturers' engineers lose sleep at night over that kind of problem in the quality control.

The irritating thing is making something with dadoes and having the shelves rattle unless you go buy a special bit or make multiple passes with a smaller bit. That's bad for production. Since I bought the recent purchase at $17 a sheet, and paid $22 for the older stuff, I guess I know why, now. Fortunately, the project I'm making won't have any dadoes in it, or I'd be real irritated. Guess I'll start taking my calipers to the wood store. Sheesh, it wasn't even a Borg store.

Lessee….(251-.223), divided by .223 is about 13% less material. *Cheaters!*


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## Petewood (May 14, 2010)

Well, they charge what they charge. I'm not saying that they can't make sheetgoods to a closer tolerance; I'm saying that as a manufacturer, I certainly would not, if doing so would raise my production costs enough to price me out of the market. I'm sure that they could manufacture sheetgoods which spec to within +/- .002", but I'm not gonna pay $250.00 for a sheet of cherry ply, and can only surmise that the manufacturers know that I won't.
Not being much of a conspiracy theorist, I'm left with the only logical steps I can come up with, and I'll spend the 40 bucks on the 3-bit set from MLCS. Further, a piece of wood (ply or not) purchased 13 years ago has no relevant comparison with one manufactured recently, even if they each began life at precisely the same gauge. In general, woodworkers (unlike metalworkers) work in increments of .01", not .001" (although a few feel more secure thinking otherwise), because a piece of wood will vary by .01" or more overnight.
The variable thickness story is a matter of objective physics.
And…...........it's not a special bit, it's a standard plywood bit. A 3/4" bit is the incorrect bit to use for a dado for 23/32 ply.


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## Jeff28078 (Aug 27, 2009)

Tolerances wasn't the point of the original post. Unless 7/16" is acceptable for 1/2". The point was why do manufacturers make 7/16" and sell it as 1/2"? And why did they go to 7/16" in the first place? Obviously it's cheaper to make 7/16" and they'll make more money selling for the same price as 1/2". Like Karson says a smaller package of ice cream may slip by most of us but when we need 1/2" plywood we need 1/2" plywood and we'd pay for it.


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## Raskal (Jan 18, 2011)

I agree with AtomJack,... pure greed.

Nothing to do with Metric/Imperial, just a way to make more $$.


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## WoodSpanker (Feb 10, 2009)

Interesting topic, and one I heard my grandfather and father grumble about when I was a kid way back in the 70's. So I would say, it is an ongoing problem. My guess would really be a mix of both. You are going to get some manufacturers cheating, and you are going to get some manufacturing inconsistencies. Guess I am what you would call a plywood agnostic.


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## 8iowa (Feb 7, 2008)

Last year, for a shelving unit, I purchased a 4×8 sheet of "3/4" birch plywood ( Chinese) at Lowes. It measured .686". This year I added to the project, but this time a contractor friend ordered some USA made birch plywood. It measured .710.

Just think how many dollars are "saved" when companies are making 4×8 sheets by the thousands.


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## Petewood (May 14, 2010)

I've not seen the manufacturers market their sheets as 1/2", 3/4", etc. I HAVE seen retailers refer to it that way. Manufacturers generally stamp their sheets. Even at Home Depot, the 3/4" is stamped 23/32.
In 30 years, I've never thought that "3/4 inch" ply was 3/4". It is generally known by any cabinetmaker that ply runs under, and always has. There are some advantages to this, among them being the ability to take cheap 23/32 birch shop, and throw whatever exotic veneer you want on it, and have 3/4.
But…..I digress….... this is one of the few threads I'm gonna check out of; because I don't understand it (beyond the fact that somebody didn't know that 3/4" ply is not supposed to be; by design).
Plus…..... if I have some of you right, then I only have to wait 6 more years, and I'll have a true 1/2" when I buy a sheet of "3/4".


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## ChunkyC (Jun 28, 2009)

It's my understanding that BB Ply is metric. We call it 1/2" and 3/4" because we use the Imperial system. It's actually 12mm and 19mm nominal.


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## D_Allen (Oct 11, 2010)

So why can't they offer both?
Some buyers would pay a little more for a full 1/2" if it were available. I know I would
Would it be that difficult to mke both? Just add a core or 2 on part of the run! Seems simple enough…but then maybe I'm just a simple guy!


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## PurpLev (May 30, 2008)

1. I don't think you can find Baltic Birch at the big box stores - unless it's a special order. what is commonly sold there is Bitch Plywood. Baltic Birch is Birch plywood specifically from the Baltic region and at a very good quality.

That aside - as ChunkyC mentioned - it is sold as 1/2" and 3/4" in the States/Canada because we use the Imperial system here, but it's actually made for metric. but still - 1/16" off the supposed size is a bit of a stretch.


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## MikeGager (Jun 15, 2009)

its been like this for a long time. thats why they make plywood sized straight router bits


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## superstretch (Jan 10, 2011)

As I've heard it, yes, there's slightly less material, but performs as well as old school, full-thickness plywood. As far as I'm concerned, a thinner material that performs just as well is a bonus in my book.


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## jusfine (May 22, 2010)

Hey Cranes, I don't remember ever seeing BB at 1/2", it's always been the 11.5mm at my wholesaler's…


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## cranesgonewild (Jun 9, 2010)

I'm on board with AtomJack. They can make specs closer to 1/2" if they wanted to. MDF is right on 1/2". I don't have 7/16" router bits, but I do have 1/2". 
Blue Mountain Woods makes a good point as well. Having it smaller allows for the use of veneers. However, I use BB because it already has a nice finish. Also, if you went with that logic, then why is MDF right on 1/2". I would prefer to veneer MDF rather than BB. 
Maybe bentlyj is right when he says we are to blame, by buying the Chinese stuff. But, that's what big box is shoving down our throats. I don't know where else to go. 
D_Allen makes a good point. Why can't we have both? To allow for veneering if you choose. 
@PurpLev, BB is sold here at Home Depot in Toronto (Oshawa) in sheets of 2'x2' and at one store I bought 2'x4'. I have never seen a 4'x8' sheet sold at a big box store.


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## Raskal (Jan 18, 2011)

cranesgonewild,... support your local shop http://www.peacocklumber.ca/ 

(not my shop, I live on the other side of the country)

google (your city) + plywood


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## Petewood (May 14, 2010)

Okay, so I can't not come back to this thread in good conscience. You have a business, and the world doesn't care. So, you just have to know what's out there, what it is, and what you need for a project. Personally, I don't buy Chinese plys, because their specs are all over the place. But I DO buy the cutters I need in order to accomodate what plys I do buy. You have to really know the business you're in, and stay with it. Chunk's spot on….. BB is metric, that's all, and so you have to "meet the ball"......hit whatever is pitched to you, and do it well. (BIG Yogi Berra fan, and my approach to woodworking has always been modelled on his baseball philosophy, with my tools and machinery as the players.)
If I sound a bit "in your face", it's because I've had a lot of luck in the last 30 years…....woodworking has been good to me, and I think that if I succeed, so can the next guy: that means you.
Stay away from what you know is c**p, work with what's left, have a blast doing it, and learn more than I have. Right now. LOL.


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## Sawkerf (Dec 31, 2009)

Imported plywood is almost always made to metric sizes and the advertised thicknesses are nominal as opposed to actual. If you want "full" thickness, buy domestic - and it's very unlikely that you'll find domestic in a big box.

FWIW, that's been the case for at least 25 years.


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## LeeBarker (Aug 6, 2010)

+1 for Pete from Blue Mountain Woods. If you're going to blame the material because your plywood shelf "rattles around in the dado" then you may want to go read some stuff on craftsmanship.

There is a big howto around somewhere by a guy who "got a great buy" on a Delta Unisaw (as I recall) at a Big Box and then because the arbor was so out of true he had to do a whole lot of work of which he was rightfully proud. But never once did he equate the "great buy" with a tool that had obviously been down-specced.

Perhaps all of us should go read the sign in Baskin Robbins. Is it still posted there? It reads a lot like this:

There is scarcely anything in the world that some man cannot make a little worse, and sell a little more cheaply. The person who buys on price alone is this man's lawful prey.
John Ruskin

As for the OP's question about the label, "nominal" has been an implied part of measurement in the wood world since just after the first time someone read a rule and said, "Three and eleven of the little marks."

Kindly,

Lee


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## cranesgonewild (Jun 9, 2010)

@ Blue Mountain, I don't believe ChunkyC is spot on. Yes BB is metric. But instead of 11.5mm, make it 12.5mm. That's all. Still metric.

@ Raskel, thanks for the link. I do buy all my rough lumber from Peacock. My walnut, Jatoba. Maple, etc. I've never asked about the BB ply. It seems that every time I need plywood, it's after Peacock is closed (early Sat. closed Sun.) I'm gonna make it a point this week to check it out.


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## Dark_Lightning (Nov 20, 2009)

Lee, I'm not looking for votes one way or the other. That "rattling" comment is a bit of hyperbole on my part. I usually have to tap the shelves in.

And yes, I can and do read the writing on the plywood, as well; 3/4-, 1/2-, 3/8- and 1/4- inch haven't been those dimensions for decades.

Oh- cranesgonewild- baltic birch usually comes in 5 foot by 10 foot sheets from the country of origin (actually, they're slightly over that in each dimension), and a lot of the stores cut then in half, so you can find both at the real lumber places.


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## cranesgonewild (Jun 9, 2010)

@AtomJack, thanks for the heads up.
And thank you everyone for the comments. There's a lot of knowledgeable people here on LumberJocks and I'm learning a lot in my journey to become a better woodworker. I'm just trying to make my life a little easier, that's all.


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## LeeBarker (Aug 6, 2010)

AtomJack, thanks for the comments. I meant the "rattling" comment only in general.

Thanks, too, for the 5×10 info. I didn't know that.

One of the differences I discovered some time ago between 12mm Baltic from my hardwood place and undescribed discount stuff: The former always has square corners. The latter rarely did. It's nice to know that before one proceeds to cut out a brazillion drawer parts! : )


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## ChunkyC (Jun 28, 2009)

Menards carries BB Ply in 1/4, 1/2 and 3/4. I use a lot of it around the w.s. but it's pricey.


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## cranesgonewild (Jun 9, 2010)

Thanks Chunk, that's what I really wanted to know. Does 1/2" BB still exist? I'll have to do my homework and check out lumberyards in the local area.


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## Dark_Lightning (Nov 20, 2009)

Barry, you crack me up! Of course, I meant buying it from a domestic vendor.

Lee, how much is a "brazillion", again? 8^D

And do you mean there is plywood out there with non-square corners? I thought I was the only one with that problem. We could solicit Martyn's help in making a diamond-shaped drawer that fits the carcase…just don't park it too close to the wall, some of the drawers won't open all the way.

I'm still trying to figure out why you guys in Canuckistan are asking about Imperial measure. Aren't all your tools metric, by now? You should have no problem finding a 12mm bit for that router with the 7mm collet…


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## LeeBarker (Aug 6, 2010)

Buckets o' fun, but seriously, take a look at Appleply: alder plies, maple faces, inch measure, 4×8 sheets, a subbrazillion different thicknesses.


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## ChunkyC (Jun 28, 2009)

>> Does 1/2" BB still exist?

I don't know if it ever did come in 1/2" nominal size. I've only ever seen the 12mm stuff.

FWIW, 12mm or 1/2", 17mm or 3/4". It's all superior in my book. All of those layers of ply, makes for some real stable material to work with.


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## Sodabowski (Aug 23, 2010)

Ahhh, the dado jig featured in one of the latest Wood Whisperer videos would sure help many of you guys having trouble cutting the proper dados for your accuracy-challenged sheet goods


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## Roger Clark aka Rex (Dec 30, 2008)

I'm still trying to find a 2"x4" ......... seems I keep getting 1-1/2"x3-1/2" sold to me instead. It's got to be fraud.


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## BobG (Apr 17, 2010)

If you really want to have some fun do a remodel on a house that was built before 1940! Them are 2" X 4" s


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