Sewer and Drain pipe is defined in ASTM standards and while they are a thickness standard, they also are a standard that prohibits pressurized flow -- they are intended for gravity flow only. Schedule 40 and 80 are presure pipe standards and their walls are much thicker than needed for dust collection ducting.
The six inch D2729 has a 3" long bell end, wall thickness of 0.100" and an outside diameter of 6.275". The specification also defines the perforated and solid versions -- it is always white in color. (The pipe also comes in 3" and 4" versions)
The six inch D3034 bell end pipe has a 5" long bell end, wall thickness of .180 while retaining the outside diameter of 6.275" It is pale green in color and comes in 4", 6", 8" and 12" sizes. You will also here this pipe referred to as SDR-35. The same specification covers a gasketed version suitable for permanent sewer lines.
Because the majority of fittings involve female ends to accept a cut piece of pipe, most are marked D2729 and D3034 since both pipe specs have the same outside diameter and they both fit these fittings. D3034 has a smaller inside diameter and is lots more expensive and heavier than D2729. My local Lowe's carries the D3034 in both the gasketed and slip-on bell end versions in 6" size, but they run about $35 per 10-foot length. While harder to find, D2729 in 6" diameter runs about $15-20 per 10-foot length. Most Lowe's stores carry 6" x 6" x 6" wyes (~$22), 22-1/2 and 45 degree els (<$10), slip couplings and a few other six-inch fittings (do not use 6" tees). Better prices can often be found at wholesale plumbing or irrigation supply stores.
I paid $15.85/10-foot length about 18 months ago at a plumbing supply house in upstate SC.