I'm dying to know, what is a/b (e.g 6/4) vs. 2x4

[bent]

I can acknowledge that when you buy a 2x4 it is not really 2.0" or 2.00" or

2.000": the sme idea in the 4" magnitude. I also appreciate the fact that "select" lumber is "better dressed": it has sharp arrisses, and it is probly straighter, maybe even holds it flatness due to its (after-green?) subsequent machining. I am not aware that may be closer to its corresponding theoretical equivalent magnitude than the otherwise lesser dressed non-select lumber of the the same nominal designation. A 2x4, either a cheap one, or a select one may be theoretically the same

Or is it that it has been made to be thast way, either bought that way or machined, exactly what the fraction says it is. eg 6/4 = 1-1/2", or 1.5x", where for the sake of argument x =0

[Leon]

"Select" has more to do with the quality of the board than "better dressed" It has less knots and has minimum width and length requirements.

it has sharp arrisses, and it is

No, the select will have fewer to no knots. It will be a better quality board.

A board is graded on both sides, and the worse side determines the final grade. The best grade is called FAS. This stands for Firsts and Seconds. These grades are the best you can get. Firsts required 91 2/3 % clear area and Seconds required 81 2/3 % FAS, which is both Firsts and Seconds combined, requires 83 1/3 % clear area.

The second best grade is called F1F, or FAS1F, (FAS 1 Face). F1F is a bit better than Select and graded the same, except the minimum board size is 6" wide and 8' long.

The next grade is Select, or SEL. This is a combination of FAS on one face and #1 on the other face. Select boards must be 4" wide and 6' long or bigger. The better face still needs to grade 83 1/3 % clear for the given area of the board, but it does not have to be as large as FAS graded lumber

The next grade is #1 Common. This grade requires 66 2/3 % clear area on the worse face.

Then you have 2A, and 2B at 50 percent, and 3A, and 3B at 33 1/3 % Basically, the required clear area drops as you get down to a 3A board.

[Jay Pique]

Theoretically, you could ask how thick the wood is before you buy it. Or you could even measure it. What's your question? And does it need to be asked?

JP

bent wrote:

[Juergen Hannappel]

[...]

so bird's eye maple is probably rated as 9B, as it has almost only knots, and burl wood which has no clear area goes ans infinity Z?

[Swingman]

[no(SPAM)vasys]

It depends... When mills are buying logs they like to consider burls, etc. defects. If they're selling the lumber they're features.

[dadiOH]

?? Are you asking what 6/4 etc. means or why a 2x4 isn't 2" x 4"?

6/4 etc. is a measurement for rough lumber. The 2x4 isn't 2" x 4" because it has been milled from a piece of 8/4.

[John Martin]

True in theory, but practice is somewhat different. With the accepted size of that 2 X dimension at 1.5", it is cut to the smallest possible thickness that will enable planing to the 1.5". 2 X used to be 1-5/8" planed, and before that it was 1-3/4" planed (and dry). Certainly you don't think the mills have gotten LESS efficient in their planing over the last 80 years?

I can't quote you any numbers, and they would vary from mill to mill, but I'd bet that for the best band saw mills today the sawed thickness plus the saw kerf is under 2" today for 2 X lumber.

John Martin

[bent]

I am still confused why the category pertaining to quality is linked to a minimum dimension quantity. Why do you need x inches to get a board of *#+* quality?

o/w the a/b is a single dimension for hardwood. It is understood hardwood, and can use the chart for sizes.

Firsts 6 inches Seconds 6 inches Selects 4 inches No. 1, 2, 3A, 3B Common 3 inches

then there is s1s, s2s

or, are these designations qualities' interchangable? I guess, eh. Firsts

6 inches Seconds 6 inches Selects 4 inches No. 1, 2, 3A, 3B Common

[Jim]

Because it isn't. All that the a/b number gives is the nominal thickness before it is planed.

Nope. The differences between FAS and Select is the length of the board. Select stock is shorter.

S1s = surface one side (planed on one side) S2s = surface two sides (planed on two sides) You left out S3s and S4s.

These designations have nothing to do with quality.

FAS = highest quality Select = highest quality with shorter boards No 1 has more knots No 2 has even more knots No 3 has lots of knots JIm

[Pop]

[dadiOH]

The quality - FAS, select, #1 common, etc is determined by yield...how much clear wood can be cut from a given piece. Each grade also has certain minimum board dimensions. Here is a link detailing it...

then there is s1s, s2s

Those have nothing to do with quality or sizes...they indicate surfaced

1 side, surfaced 2 sides.

[Leon]

And THEN......You can almost throw all this out the window when it comes to construction grade lumber and a few exotic hard woods.

[Odinn]

On 4/2/2006 4:07 PM Pop mumbled something about the following:

Oh yeah, like you did anything to answer his question. Now if you can decipher what the hell he was asking and come up with a good answer that was better than what has been said, then share it with the rest of us.

[Larry Blanchard]

Welllll, not exactly. Hardwood boards are graded on the minimum size of clear cutting that can be derived from them, not on the size of the board. There are certain minimums a board must reach for each grade. Your mention of knots is one defect that can lower the clear cutting size, but so can splits, waney edges, and probably more things I don't remember.

And, AFAIK, select is a term that means the board meets FAS standards on one face, but not the other.

[Pop]

No one seems to know, so ... Board thicknesses are basically measured in quarters of an inch. Thus, rough cut lumber is given as, say, 5/4 meaning 1 1/4" thick. 6/4 is 1 1/2, and so on. So if you ask for 5/4 lumber, you're asking for rough cut, unplaned lumber. Once it's planed, then you get the 2 x 4 that's actually closer to 1 1/2 x 3 1/2 (take 1/32, depending on humity, the yard, machines etc etc etc.).

Sfunny none of you geniuses could bother to come up with at least that much; it's rather elemental, really, although there's really a tad more to it. You're still a bunch of ignoramusses for the thread activity,

90% of which was OT from the poster's question. The OP is long gone, I'm sure. You should be, too.

Pop

Pop

[Odinn]

On 4/2/2006 10:05 PM Pop mumbled something about the following:

You didn't explain a damn thing that wasn't already explained, but you STILL didn't answer the OP's question. Now try again.

[Swingman]

... and you lead by example.

Close, but still flawed by a basic lack of understanding ... go back and read the link in the first reply to the OP and take the first step in educating yourself.

Then on to the following and you'll see how incomplete and far off you really are:

[Swingman]

LOL ... I think the "humity" got to Pop's.

[Gooey TARBALLS]

Is it necessary to take such a tone with folks here? Would you speak to them this way were you talking to them in their shop? In yours?

I'm not at all sure, but suspect many - if not most of us are participating here to learn from one another. And, when we offer a comment, do so with the honest intent to share what we have learned here or elsewhere upon the assumption that it is correct. That is, we do not contribute items we know to be false or incorrect.

The comments are not to an individual (although one does have that option) but to the group as a whole. Therefore, the ad hominid attacks on folks doing their best (which may not be up to the standards of the highest achievers reading) are inappropriate.

Better to contribute the URL of an authoritative source and offer the reader an opportunity to revisit the subject than to attack his or her intelligence.

I may be the only one on the list that finds this sort of arrogance annoying, but I suspect it is less than pleasant for many more.

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