I feel like a back-woods bubba rookie, but please explain what these numbers mean (8/4, 6/4) when referring to wood.
Is it the number of cross-cut tree rings per inch or something?
Are higher numbers better?
-Anonymous (oops, that doesn’t work…)
Discussion Forum
Get It All!
UNLIMITED Membership is like taking a master class in woodworking for less than $10 a month.
Start Your Free TrialCategories
Discussion Forum
Digital Plans Library
Member exclusive! – Plans for everyone – from beginners to experts – right at your fingertips.
Highlights
-
Shape Your Skills
when you sign up for our emails
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. -
Shop Talk Live Podcast -
Our favorite articles and videos -
E-Learning Courses from Fine Woodworking
-
-
Replies
4/4 = 1" or 25 mm thick, rough sawn.
5/4= 1-1/4" or 32 mm thick, rough sawn.
8/4= 2" or 50 mm thick rough sawn, etc..
Therefore in the US you go to the lumber yard and buy 'so many' board feet of rough sawn 4/4 poplar, maple, oak, etc.. A board foot is a 1/12 of a cubic foot, which is 1728 cubic inches, and a board foot might be described as a piece 12" long X 12" wide X 1" thick, i.e., 144 cubic inches-- the 1/12 of a cubic foot. Any piece of timber that comes out at a volume of 144 cubic inches is a bd. ft., (board foot) e.g., 12"L X 6"W X 2"T= 144"³ Slainte, RJ.
I get the board foot thing. That makes sense.
The 4/4=1", etc. is just screwey. But then I've always had a problem with a 2x4 not being 2" by 4".
Thanks for the explanation
-Ken (Palmyra, Nebraska)
Ken, your 2 X 4 started as a rough sawn piece that was 2" thick by 4" plus wide, and was described as 8 quarter [of an inch thick (and written as 8/4)] by 4" width. The /4 dimension refers specifically to the thickness, not to the width. To get your 2 X4 flat and smooth means you must lose something from the rough sawn dimensions to end up with a piece about 1-3/4" X 3-3/4"-- I seldom buy or use the pre-milled dimensioned lumber you're talking about and sold at lumber yards and places like Home Depot for carpentry type work, so I'm not sure what the acceptable industry standard final thickness must be when it's milled from a piece of rough sawn 8/4. Slainte, RJ. RJFurniture
So now explain, if you will, this 'd' business for nails. Why not a 1" panel pin, or a 3" wire nail?I've had a sort of explanation of this and */4 timber measurements from a certain American of my acquaintance (who had the bloody audacity to criticise Pounds, shillings and pence as 'complicated') but perhaps I might understand a fellow Limey better.
Ah sir, what a crafty englishman you must be, (read as complimentary). The most widely used types of nails include the common, box, casing and finishing. All of these nails vary in head type and diameter. Length for these nails is designated by the penny (d). This is an old English system.
How does the 'd' relate to the length? -- how, for example, do you work out the length of a 6d?
I forget the details of the system, but it was English in its origins.
The penny system starts off with the first 1d=1/2", the second is also 1/2", but from there they go to 1/4" per penny designation. This works out to a 3d nail being 1/2"+1/2"+1/4"=1 1/4" long, a 4d=1 1/2 and a 6d=2".
An easy method to tell what size nail you need for your particular thickness of wood is a penny per eighth inch of thickness. A board 3/4" thick is 6/8th so you would need a 6d nail. Is that any easier or is it just something I've lied to myself about all these years?
Tom
Wood was originally sawn by 0.25" increments because that were the control levels on the set works at the saw mill. If the sawyer wanted to advance the log to cut 1" thick material, he would advance the mechanism 4 notches plus one more because the kerf losses with those old circle saw blades were 1/4".
Saw mill operators recognized that lumber shrinks when it dries and they did not want to absorb those losses. 4/4 lumber has a green dimension of 1". This is, more or less the actual dimension. Out of the kiln it will be less and then there are planer losses. It is still considered 4/4 lumber but that 4/4 dimension is now consider to be nominal. Most S2S lumber (that is planed on both faces so it is Surfaced 2 Sides) has a target size of 13/16". If a piece of wood cannot attain this 13/16" dimension when S2S, it will be considered as 3/4 stock.
Softwood grading standards and sizing are very different from hardwood standards and practices. The previous contributor who indicated that a 1x4 was 0.75" x 3.5" is correct only if referring to softwoods. You could buy a piece of hardwood that is rough (not planed) that will only be slightly less than 1" (say approximately 15/16") -- the reduction in dimension due to wood shrinkage during drying. Were it rough green, it would be 1". The width of the hardwood piece, depending on scaling protocols could have a width anywhere between 3.5 and 4.49" (rounding up and down to the nearest inch).
Be aware that in both hardwoods and softwoods a 1x4 implies nothing about the wood moisture contact. In softwoods especially, wood will be planed/sized to 0.75" and still be wet.
Be aware that board feet has a differing meaning depending if you are talking about lumber (1x12x12) or if you are referring to log scaling practices. There are about 6 or 8 regularly used log grading scales (Doyle, Scribner, International, Cubic) that all will give a different board foot level for the same log. It seems that loggers tried to figure out a way to get something extra from the sawyer. And yes it is extremely confusing going from log to lumber scale.
As to the source of the "d" referring to nail sizes, it is actually of Roman origin. The "d" stands for denar (denarii) which was a silver coin. Over time, the coin metal was changed to bronze or copper and was devalued. A copper denarii became a penny which is why a 16d nail is still referred to as a 16 penny nail. Anyway nails were sold by weight, then as now, because it is still easier to weigh a bunch of nails then actually count them. To make sure that some level of fairness (or size/quality control) the weight of various sized nails implied a certain number of actual nails. Tables exist so that if you need 100 nails, you simply have to go to the chart and for the size of nail you desire, obtain so many pounds. The correlation that may help you understand the connection to a silver coin is that in earlier, more primitive societies of technology, nail were made by hand and due to the labor involved (not to mention the mind deading repetition), and the scarcity of iron, extremely valuable.
You're knowledge is obviously well above that of mine. Being the type of person that I am, I wonder if it would be possible for you to provide information about some of the reference material that you used to gain your knowledge of the subjects you respond to in your posts. I find it fascinating and I love precise details like you have brought forth. My reference material seems way too vague compared to the sources you must have. In short I guess I'm saying that I have a real desire to be absolutely correct and I'm begging for help. Thanks in advance if you can help and all of the help from both the past and, as I see it, the future.
Edited 8/9/2002 3:17:06 PM ET by no one
No one/some one/every one:
Thank you.
I have been accumulating knowledge and information regarding wood and woodworking since about forever. As a kid growing up in Chicago, I bet I went to every museum dozens of times. I got my undergraduate degree from SIU Carbondale in Medieval History studying under a professor who was both a bricklayer and an expert in Medieval Master Masons. For my senior paper, I wrote about the woodworking guilds of England.
I started in the trades working in a refinishing shop in Evanston IL with some time in an upholstery shop for about 9 months of half days. Since I am color deficient (1 in 10 males are) I focused on woodworking and repair.
After I got married, I went to Penn State and got a master's degree in Forest Resources (read as wood science and technology). I then spent two years at Masonite at their R&D center. I opted for self-employment (repair, custom woodworking, refinishing) during the recessions of the early '80's, remodeled a home built in the 1890's.
I had a chance to work at the forest products department at Oregon State University and figured that Oregon was a better place to live than the Chicago suburbs (especially for my children). I worked in a departmental extension role answering a lot of the questions that came into the department, ran a continuing eduction program for sawfilers and mill personnel, and did research including a book entitled Hardwoods of the PNW.
I read everything I can get my hands on regarding wood and furniture. I go to lots of bookstores and libraries. I read professional journals and books on the history of technology. I have got about 10 feet of wood/furniture books and a four drawer file cabinet filled with nothing but files on wood stuff.
For wood info, I rely primarily on Panshin and deZeeuw's Textbook of Wood Technology and the numerous and varied USDA publications especially the Wood Handbook, the Dry Kiln Operators' Manual and Peter Koch's 3 volume tome on Hardwoods on Southern Pine Sites. I have spent days reading and re-reading Koch's book on Wood Machining Processes along with spending hours and hours talking with sawfilers and sawyers. I had the great opportunity to work with some very talented and skilled individuals -- just watching them work was very informative.
Henry Mercer's book on Ancient Carpentry Tools is an education unto itself. So is Fine Woodworking as a magazine; I was one of the early suscribers and have read them.
I was just looking for a pamphlet on Nails and Nail History but it apperently is in storage boxes -- another sources tells me the name of it as "Nail Chronology" Technical Leaflet 48 by L. H. Nelson and published by the American Association for State and Local History in Nashville TN. This is not however the only source or reference where the "d" nomenclature/history was presented.
So kill your TV and spend more time in libraries, bookstores, and other peoples' shops
Thank you so much for the pleasant and extremely interesting reply to my request. I am humbled to say the least. Perhaps someday I too shall have aquired at least some of the experience and knowledge that you have.
Much like you I am a do'er and and a learner. I think my pattern is something on the order of... read, do, learn, read, learn, do again, learn again. Its a long process for me but none the less rewarding. Thank you again for the tips. Please keep them comming.
By the way... my TV is off most evenings, wood is far more intelligent.
NIEMIEC1 wrote: I had a chance to work at the forest products department at Oregon State University and figured that Oregon was a better place to live than the Chicago suburbs (especially for my children). I worked in a departmental extension role answering a lot of the questions that came into the department, ran a continuing eduction program for sawfilers and mill personnel, and did research
including a book entitled Hardwoods of the PNW.
---------------------
Where might a copy of that book be found? I very much prefer to use our local and regional woods, hard and soft for my woodworking. Chinquapin [sic?] is my favorite with Oregon ash close behind.
Do you still live in/around Corvallis? My younger son (16) lives there with his mom (my ex). I'm located in Cave Junction, in southwestern Oregon.
--
Lee in Cave Junction, Oregon
On the Redwood Highway
Alas the publication is no longer in print and the available copies have been distributed. When available, this publication was the most requested of anything distributed from the College of Forestry. If I were not paranoid, I would think that there was some sort of personal motivation against it getting reprinted.
I no longer live in Benton County. At even two counties distant (Marion) this is still too close for the "X".
I like Chinkapin too. My only negative comment about it has to do with its color. I find it necessary to color it (dyes and/or glazes) so that it becomes more brown. It machines wonderfully and I love the way it sands. To increase its appeal and value, I recommend it be called Golden-leaf chestnut.
Of the Western hardwoods, my outright favorite is Bigleaf maple. For all intents and purposes, it is comparable (physically and mechanically) to Black cherry (Prunus serotina). The color and grain patterns however are far superior to anything I have seen across The Divide. In my opinion, had this country been settled west to east, it would be North America's premier cabinet wood.
I am not a big fan of Red alder. There is nothing distinguished about it albeit the "great imitator". I doubt if I would consciously chose it for any project! And surprisingly, I don't use Oregon myrtle primarily because I find the color too green (and therein lacking warmth).
Despite my efforts to promote better utilization of these species, the production volume is still limited and therefore sometimes difficult for me to get the sizes, grades and quality I know exists.
My compliments on a thoughtful and extremely informative answer. You've raised the bar for us all....
I don't know how it as determined that a 6 penny (6d) nail would be exactly 2" long. Maybe you can make more sense of it with the help of this chart.
Size Inches mm Gauge Approx Number to Pound
60d 6 150 2 11
50d 5 1/2 137 3 14
40d 5 125 4 18
30d 4 1/2 112 5 24
20d 4 100 6 31
16d 3 1/2 89 7 49
12d 3 1/4 83 8 63
10d 3 75 9 69
9d 2 3/4 68 10 1/4 96
8d 2 1/2 62 10 1/4 106
7d 2 1/4 56 11 1/2 161
6d 2 50 11 1/2 181
5d 1 3/4 43 12 1/2 271
4d 1 1/2 37 12 1/2 316
3d 1 1/4 31 14 568
2d 1 25 15 876
It doesn't really relate except that the bigger the "d" the longer the nail. Over a small range of sizes there is some formula you can come up with but it doesn't work for the full range. I've heard that the "d" used to be the cost for a pound of nails of that size but I never understood why larger nails should cost more per pound. A pound is a pound, right?
Right, so what do I ask for if I want a 3/4" oval brad (finishing nail)?
I can't tell if you're being silly or not so I will assume not and suggest that you ask for them just as you have explained it in your post. If the clerk gives you something other than expected then ask them the correct terminology for the item as you have described it. Hopefully they will know the differences by something other than the local terminology and you will have your answer. In other words, I don't have a clue.
I can't tell if you're being silly or not
No, I was interested in the terminology once the nail was shorter than 1" -- thank you for the explanation.ALLThank you for your help -- I can't pretend I shall remember the exact details but I've a better hold on it now.
Incidentally, I'm working in Imperial again for the first time in 30 years and while trying to mentally subtract 1 5/8" from 7 1/16" I realised just how much easier metric is! (42mm from 180mm)Now, anyone want an explanation of Pounds, Shillings and Pence? -- anyone?
Thanks for the explanation of quarters. The nail sub-thread was a real bonus.
I'll keep this thread bookmarked - so I can re-read when the other half of my brain wakes up!
Seriously, Thank you.
-Ken (Palmyra, Nebraska)
RJ,
I've left the details at work, but minimum thickness acceptable is governed by a national standard. Here, minimum sizes for 4" x 2" (100 x 50mm) post-dressing are 91 x 41(?42?)mm; 1"/25mm dresses down to a minimum thickness of 19mm (just a touch below 3/4", in imperial measurements), and; 3/4" dresses down to 12mm. There is nothing in the standard stopping a mill from dressing their 1" rough sawn to 20mm or 21mm, providing the face is adequately dressed. However, for convenience, mills set their machines at the same setting, usually to meet the minimum standard to avoid changing settings every board. (on some hardwoods, the setting may be 43 - 44mm as the boards are routinely dressed by the time this amount has been taken off the board and to take any more off the board is a waste of time and money)
These standard thicknesses may be different in the US.
I'm happy to post the complete table of rough sawn size vs. dressed size when I get back to work and have details in front of me, if it's of any use. Pls advise.
Cheers, Eddie
Edited 8/9/2002 10:36:50 PM ET by eddie
Ken, Sgian explains it well. 4/4 is actually 4 quarters. Since an inch is divided into quarters then 4/4 is actually a full inch. I think your confusion may be that you are trying to relate this with wood grades. These are actual wood measurements that the lumber mill uses when they cut the wood for the first time. This is what is referred to as rough sawn as Sgian states.
Lumber grades are ratings that the lumber mill assigns to the wood after it has been rough sawn. For hardwoods these grades are First and Seconds, ( FAS=highest grades), Selects, which is one side equal to FAS and one side No. 1 common and No. 1 common (Thrift).
Softwoods are graded as C Select and Better, D Select, 3rd Clear, No. 1 Shop, No. 2 and No. 3.
I have seen these ratings differ by locale but these are what the National Hardwood association and the Western Wood Products Association have designated.
You may also be asking yourself why when you go to the lumber yard and ask for a 1x4 you get a piece of wood that measures 3/4" x 3 1/2". This is because unless you use the correct terminology it will be assumed that you want milled lumber that has been surfaced on four sides, (S4S). The loss is due to the milling of a piece of wood that started out as 4/4 x 4". It will cost more because you are being charged for the rough sawn size of the wood plus the milling.
To confuse the matter of 4/4 they also cut wood differently. There is plain-sawn, quarter-sawn, live-sawn and rift-sawn. None of these terms have anything to do with final cut dimmensions but can affect quality. If you want more info on these terms I suggest you check out books at your local library on wood and wood products. The pictures will help you understand it much better than I could ever explain it.
Hope this is in someway helpful.
This forum post is now archived. Commenting has been disabled