Plywood question

[Scott Loven]

What is an acceptable thickness tolerence for 1/4" AC plywood?

I had some delivered today that measures .20".

Scott

[john bateman]

I've bought and used expensive mahogany ply that was the same thickness. It was used as the panel in frame and panel doors, and there were (a few) router bit sets that cut the slot for a perfect fit. So I'd guess it's not that unusual.
Although that doesn't really answer your question.

[Jamie Buxton]

Dunno about construction plywood, but .20" thick is pretty much what hardwood plywoods run these days.

[Scott Loven]

the 1/2" measured .49, the 3/4" measured .75, both of which I find acceptable given the nature of plywood. .2 is 20% off! An undersized plywood bit is 15/64", this piece is around 13/64th!
Scott

[Curt Harms]

the 1/2" measured .49, the 3/4" measured .75, both of which I find acceptable given the nature of plywood. .2 is 20% off! An undersized plywood bit is 15/64", this piece is around 13/64th!
Scott

5.5 mm seems a common size for "1/4" ply. 5.5 mm=.2165" 5.0 mm=.1968" Pick one.

Curt

[Cliff Rohrabacher]

Judging from some of the garbage I've got from the BORG lately the manufacturing tolerance on 1/4" ply is:
+0.0" / -0.250"

On 1/2" ply it's +0.0" / - 0.500"
Etc.

[glenn bradley]

Since you had it delivered, I'm assuming a bulk supplier. Sounds like you got metric stuff there.

[David DeCristoforo]

The "problem" is that what you are buying is not 1/4" plywood but 5mm plywood. Most ply made "overseas" is made to metric measurements. If you want "true" 1/4" ply, you need to find a source of "domestic" ply. This problem is exacerbated by the fact that most cope and stick cutters still use a 1/4" groover. Some can be ordered with "optional" 5 mm groovers but not all. And, needless to say, the groovers on one piece cutters are not interchangeable.

[Don Naples]

I have a project that uses 1/4" plywood. The only true .250 plywood I found is Apple Ply. It is from a domestic source. Depending on your needs, you can get C2 if you need the full sheet or when it is available buy shop grade if you can work around the flaws.

[David DeCristoforo]

Actually, all of the 1/4" hardwood veneered material I have gotten in the several years has been "composition" core (AKA (yecch) MDF). Don't like it at all but it seems that true 1/4" plywood is on the endangered list....

[Peter Quinn]

Last time I picked up a piece of 1/4" MDF for a small annoying job for a family member (any job involving MDF tends towards annoying) it measured .1875". Coincidence? 3/16"? Oddly the 1/4" MDF at my usual supplier mics exactly .250". I'd expect a 1/32" under on plywood, or possibly 5.5 or 5 millimeter, but 3/16"?

I have cutters to deal with 5mm and 5.5mm, but I didn't think to get one in .1875". I think the Borg may actually be cheating people 1/16" at a time!

[David DeCristoforo]

It seems like the only thing that does not get smaller is the price....

[Karl Brogger]

Solid is still a choice for panels. I use MDF core most of the time for flat panel doors. Is it the dust that bothers people about MDF?

[Blake Holton]

What is an acceptable thickness tolerence for 1/4" AC plywood?

I had some delivered today that measures .20".

Scott

Scott:

For domestically manufactured plywood certified to the ANSI/HPVA HP-1-2004 standard the allowable thickness tolerance for a panel 1/4" or thicker is plus 0", minus 3/64". So, for a 1/4" panel the acceptable thickness range would be 0.203 - 0.250".

It also follows that the acceptable thickness range for a 3/4" panel is 0.703 - 0.750". Most manufactures offer products produced with a "blank" or "platform" (interchangeable terminology) that are specifically designed to be very consistent in thickness (low variability) and often measure closer to the upper range of the thickness specification.

Regards,

Blake