9/8 scale

[Patrick NC]

I'm familiar with 4/4, 5/4, 8/4 etc...
My new mill has 9/8. Has anyone seen this before and why would you use it? 

 

[Don P]

Typically 4/4 is sawn at 1-1/8".

[Southside]

Yup, hardwood 4/4, just marked in a hipster sort of way. 

[Patrick NC]

So 9/8 would give me true 4/4? I wonder why they didn't factor that into the 4/4 scale? 

[Southside]

In hardwood, yes that would be true 4/4. I don't see a 4/4 scale on there as such, just a true 1", which would be a pine 4/4 scale, so maybe it was their way of making it easier to read. 

[Patrick NC]

That makes it a little less confusing. Thanks 

[Ianab]

If you saw set at exactly 1"+ kerf, and get ANY wave in the board, even 1/16", it's now under size, and technically a reject. If you saw at 1 1/8", you can have up to 1/8" variation, it's still "in spec". Not a great board, but it's still measured as a 4/4.  

In an ideal world the saw would always track dead on, and the log would never move due to internal tension. But back in the real world, there are knots, grain run-out, tension in the log etc and ANY mill can get a little variation sometimes. 

[Haleiwa]

Pallet mills sometimes specify 9/8 coming from a circle mill (usually jackets from making ties) so that they can split the board with a vertical bandmill and have two half inch pieces for the pallet deck.