Plywood Grades Question

[Dennis Putnam]

I am a little confused by some plywood grades. I understand what the letters mean (A,B,C,D) but not the numbers (1,2,3,4). For example what is the difference between AA and A1 or BC and B2, AC and A3, etc? Why are numbers only the second character (no 1A or 1C), why use numbers at all? Thanks.

[Jamie Buxton]

Letter-number grades (e.g. A4) are hardwood plywood. (To be clear, "Hardwood plywood" generally means plywood in which the face veneers are hardwood, but the interior plys are softwood.) The letter indicates the quality of the better face, with A being best. The number indicates the quality of the other face, with 1 being best. For instance, A1 plywood has two high-quality faces. For another instance, A4 plywood has one good face, and the back face might not even be the same species as the front.

Letter-letter grades are softwood. The first letter indicates the quality of the front face, and the second indicates the quality of the back face. A is good, going down to D, which is bad. For instance, AC plywood has a good front face, and a not-so-good back face.

[Blake Holton]

HWPW (Hardwood Plywood) grades are generally specified by a species and grade. For instance, 3/4 A Maple 3 Maple would imply a 3/4" panel with an A grade maple face and a 3 maple back. It is also sometimes written as A-3 Maple. As for the number grades, in general, a C face is generally comparable to a 1 back. So, a C-1 Maple should look just about the same on the face and back. To complicate things more, it is also possible to have an A-A Maple (A grade Maple face and an A grade Maple back). All combinations of letters and or numbers are possible.

[Dennis Putnam]

Thanks for the replies. I'm afraid you have managed to confuse me even more. I guess I need to be more specific. First, I was referring to hardwood plywood, sorry for not being specific. I am trying to decide between Birch or Beech for a home theater cabinet. However, the 3/4 plywood grades available are (neither says which or what is the softwood side):

Beech - AB (that in and of itself is confusing if letters mean softwood)
Birch - B2 (knots give a piece character so I don't object to them but why is the hardwood considered the back side?)

I guess the bottom line is I can't really decide until I look at both. The grading systems is not very helpful. My delimma is that from what I read birch is a little easier to finish but I may not be happy with grade 2. That means it may not stain easily enough for a beginner. On the other hand, if A refers to the beech side then I might like that better in spite of the slight challenges finishing it. Finishing it may be a problem anyway since I plan to have glass doors, the inside, if softwood, may not come out right.

[Blake Holton]

Beech - AB (that in and of itself is confusing if letters mean softwood)
Birch - B2 (knots give a piece character so I don't object to them but why is the hardwood considered the back side?)

Dennis -

So, if we look at the AB Beech, the face should be an A grade beech veneer and the back should be a B grade beech veneer. The core (although not specified here) is most likely a softwood veneer core comprised, for example, of fir or another softwood species. The Birch will have a B grade face (of birch veneer) and a 2 back.

In comparing the two sheets available to you, the Beech is a much higher grade panel. The choice, as you point out, is strictly one of personal preference.

By all means, view the panels to determine if the look is what you want. Choose carefully when picking out the sheets. Take your time and look over each one, just as you would when buying lumber.

Hope this helps clear things up, if not, let me know.

Blake

[Dennis Putnam]

Thanks for the information. I still don't understand the grading. If numbers refer to hardwood then I would expect the beech to be grade 12 and the birch to be 22 (assuming both sides are beech or birch). If the numbers do not really mean hardwood and the letters mean softwood then I'm back to my original question. Why have numbers? Supposed the beech was A2 or 1B or 12. How would have have been different then AB? Same with the birch. Suppose it had been BB or 2B or 22. What is the difference between that and B2?

[Charles Bruno]

Hello,
here's a link that might clear up some of the confusion
hope this helps http://tpub.com/content/construction...s/14043_78.htm

[Blake Holton]

Thanks for the information. I still don't understand the grading. If numbers refer to hardwood then I would expect the beech to be grade 12 and the birch to be 22 (assuming both sides are beech or birch). If the numbers do not really mean hardwood and the letters mean softwood then I'm back to my original question. Why have numbers? Supposed the beech was A2 or 1B or 12. How would have have been different then AB? Same with the birch. Suppose it had been BB or 2B or 22. What is the difference between that and B2?

So the letters refer to the face (versus the back) of the sheet. So, the reason you always see A-2 Maple (not 2-A Maple) is that the face is specified first. Don't confuse yourself with softwood versus hardwood. Keep in mind that softwood plywood (the kind used for sheathing in home construction) is also designated by letters, but the descriptions are not the same.

For hardwood plywood just remember that the face is specified first, and is usally a letter. The back is specified next, and can be either a letter (A, B, etc) or a number. An A grade Maple veneer is not equal to a 1 grade. In generall (keep in mind I've said general) a C grade face is about equal to a 1 grade back, and a D grade face is about equal to a 2 grade back.

So, in your question above, B-B birch would be a good grade of plywood with both faces veneered with B grade birch. A B-2 sheet would have a very nice B grade face and a kind of ugly (IMHO) 2 grade back. This panel would be fine if the 2 face were used for the back of an entertainment center and the B face was visable, for example.

Blake

[Dennis Putnam]

Hello,
here's a link that might clear up some of the confusion
hope this helps http://tpub.com/content/construction...s/14043_78.htm

Thanks but I guess I'm just dense or the manufacuturers don't go by their own standards. If you see my previous question, the only thing clear to me is that the grades indicated by the retailer do not comply with the so-called standards. According to the standards the grade AB for beech is simply wrong. Further, logically, using numbers is completely unnecessary.

[Jim Becker]

Tthe only thing clear to me is that the grades indicated by the retailer do not comply with the so-called standards.

Indeed, this is also a problem with hardwood and softwood lumber at the retail level...some places "roll their own" when it comes to "grading" and they can be pretty creative about it, too...