Ply T

[dicktimber]

Is it me or does anyone else have problems getting consistent thickness ply wood?
I usually use 6mm for drawer bottoms rebated into the drawer sides and front.
The first sheets I bought were 6.1 mm and I purchased a 6.4mm cutter which worked fine.
The next few sheets I purchased have come in at 5.0 mm.
When i queried this, the buyer said they purchase on the order 5.5mm which seems to be the norm when I rand round.
They couldn't tell me what the tolerance range was for the thichness.
Now, this means that at 5.00mm thick I am loosing over 1 mm in thickness, which does make a big difference in stiffness on a mid size drawer, making the drawer bottom flex more,...plus I have to buy a new cutter.
Is this normal?
What tolerances are used by manufacturers on ply thickness?

 

[Digit]

About the same accuracy as the country man's mile I find Dick.

Roy.

 

[Argus]

.



Funny you should say that......

I have always had to run a side rebate plane up and down drawer grooves to get ordinary "1/4" inch ply to fit.

I thought it was just me.... ply tolerances are all over the place.



.

 

[Digit]

Even across a sheet in my recent experience.

Roy.

 

[trousers]

Here you go for Finnish birch ply satisfying the EU315 standard for tolerance:

5mm (3ply) 4.7 - 5.3
9mm (5ply) 8.8 - 9.5
12mm (7ply) 11.5 - 12.5
15mm (7ply) 14.3 - 15.3
18mm (9ply) 17.1 - 18.1
21mm (9ply) 20.0 - 20.9
24mm (11ply) 22.9 - 23.7

I'm fairly sure inferior grades of ply have a wider tolerance.

 

[wobblycogs]

So to meet the specification 21mm and 24mm ply can never actually be as thick as the name would imply? Very weird. Why do I get the feeling that some droid that has never done any woodwork came up with that spec.

 

[flounder]

To go off on an ever so slight tangent :roll: what are my chances of successfully edge jointing some 6mm marine ply? I have some in 7" strips that I want to utilise to make some drawer bottoms with. I intend to employ a central munting to help with the load.
Cheers and sorry(ish) for hijacking the thread!

 

[big soft moose]

minimal i would suspect 6mm is too thin to take a biscuit.

what you could do is plane them up to butt joint then put a couple of strips accoss the tother way (on what will be the drawer bottom) to help hold it all together.

but that said 6mm ply isnt expensive so why risk spoiling the ship for a ha'p'worth of tar