Kevin asks,
Is there an industry-standard tolerance that would be applied to the assembled dimensions (Length, Width, Depth) of a 2pc carton? I would question whether multiple processes should lead to alternate tolerances when compared to a single process 1-piece carton. I would also wonder how carton size would play into the tolerance and if there are any steadfast rules and/or guidelines throughout the industry.
The particular carton I am trying to apply tolerance to is a 2pc Partial Overlap Top, HSC bottom where the width panels are die cut and the other scoring off of a press and then offset stitched within the length panel for reference. I am trying to hold +/- 1/8” on all dimensions now. These tend to be around 76 x 32 x 50” with 2” POL.
According to the Joint PMMI/FBA publication PMMI B155-TR2.2-2011, the tolerance of a RSC panels are +/- 1/16 inch per panel with an overall blank tolerance of +/- 1/8 inch for both length and width. Also, I believe there is a TAPPI publication of dimensional accuracy which may make reference to tolerance.
Slot depth should be within 1/8 inch from the center line of the corrugator score. Slots should also be centered within 1/16 inch of the aligning scores.
No allowance is given for carton size, caliper, substrate or complexity of design in this specification.
I haven’t found any reference to multiple piece cartons which would lead me to believe that there would be an additional allowance for a multi-piece carton.
So, based in this information, it would make sense that the overall assembled dimensions (interior and exterior) should be within, and controlled by, the +/- 1/8 inch overall tolerance of the RSC or die-cut blank.
One other note to toss in here. While the PMMI/FBA publication above may note that +/- 1/8 inch over all is acceptable, today’s customers are typically demanding something closer. With today’s drive and anvil technology +/- 1/16 inch (1/8 total) may generally be considered the norm, but more and more customers are demanding closer tolerances and expecting little to no variation.
— Ralph
askralph 
March 22, 2018 at 7:13 am
Just a note regarding the FBA/PMMI document Ralph referenced. It is very important to understand the scope of the document. It was developed to establish bench mark tolerances that box makers and packaging machinery manufacturers agreed we could consistently make and they could consistently run on their machines.
Section 2 the Scope identifies specific styles, sizes and board grades that fall within the scope. The particular package referenced above does not fall within the scope of the Technical Report.