Looking for a generally accepted specification and/or standard for bow across a wood top. I remember (I think) seeing something that an 1/8 inch is allowed across a 36 inch top. Can anyone direct me in the right direction. Thanks in advance!

The accepted standard that I am aware of is 6mm of bow is allowed over a 3 meter top.

Or approx. 1/4 inch of a bow is allowed over a 10 foot (120 inch) top.

Or as you stated closely, 1/8 inch of bow is allowed across a 60 inch top.

Hope this helps........

I had e-mailed Frank( not sure Frank is still with us) on this and am awaiting a response. Does anyone know from what standard this comes from. Someone said that it was a design standard. Any help would be appreciated. Thanks in advance.

I had e-mailed Frank( not sure Frank is still with us) on this and am awaiting a response. Does anyone know from what standard this comes from. Someone said that it was a design standard. Any help would be appreciated. Thanks in advance.
I'm aware of at least one Standard, but I do not have a copy, nor have I ever read through one:

EN324-2:1993
Title of Standard:
Wood-based panels.
Determination of dimensions of boards.
Determination of squareness and edge straightness
Panels, Wood products, Wood based sheet materials,
Boards, Straightness measurement,

This is a Standard used in the European Union and such Standards are usually available through BSI, who can probably tell you if there is an international or USA comparable one.

Thanks Wes. A Customer was wanting to know if there was a standard or if it was ours and wanted a copy of the standard,if one existed.

Have been striking out. The EN and its American counterpart does not address allowable bow/flatness/warp. I searched the net over but found nothing. Any other takers on the question before I leave you alone!

Have been striking out. The EN and its American counterpart does not address allowable bow/flatness/warp. I searched the net over but found nothing. Any other takers on the question before I leave you alone!

I'm a little late to the dance, but I notice that in your initial post, you say you're looking for a "standard for bow across a wood top." Top of what? If we know more about your application, we might be able to provide better answers.

I'm a little late to the dance, but I notice that in your initial post, you say you're looking for a "standard for bow across a wood top." Top of what? If we know more about your application, we might be able to provide better answers.

Jim, I learn a lot from your responses. ;) esp. your eye for minute details :applause:

Wood desk top 18x54.

Wood desk top 18x54.
In what market? For example, if it's office furniture you're dealing with, you might be able to get some information from BIFMA (http://www.bifma.org/index.html). Tell us more about what you're doing, and why you're looking for standards.

office furniture. We have a field issue and sales insist there is a standard. I contacted BIFMA they have nothing. I have contacted our suppliers and they know of nothing. They have their own allowable tolerances and if I can find no standard, we will incorporate theirs.

office furniture. We have a field issue and sales insist there is a standard. I contacted BIFMA they have nothing. I have contacted our suppliers and they know of nothing. They have their own allowable tolerances and if I can find no standard, we will incorporate theirs.

No standard has any standing unless it's referenced in the contract. Unless you and your customer have agreed to a standard, there isn't one. As far as your field issue is concerned, if you have an unhappy customer, it's best to do what you can to make them happy, unless they're being very unreasonable. I would think that you might want to work with your suppliers, and trace things as far back as possible--to the mills, e.g., in order to find out what standards are being used.

To close this I would just like to thank everyone for their response. I have concluded that there is no standard or generally accepted specification for cup, warp or twist and it is basically a contractual agreement with both parties. There is a document that tells you how to measure cup, warp and twist. If anyone is interested it is a Composite Panel Association: Standard Method For Measurement Of Warp In Composite Panels-August 15,1996-last reprint October 9,2003.