Reamer & conduit bundle size calculator
What size to backream a bore for your product — a single pipe or a bundle of conduits. Enter the pipe size (and how many), pick your backream factor, and get the hole size to ream.
A bigger hole pulls easier but uses more fluid and makes more spoil, so most crews ream about 1.5× the product envelope and step up for long shots, rock, or tight-clay swell. Bundle sizes assume the conduits pull as a tight cluster; a loose or oddly-shaped bundle needs a bit more room.
Common questions
A common rule is about 1.5 times the outside diameter of what you are pulling — so a single 2 inch product reams to roughly 3 inches. Step up toward 2 times for long shots, rock, or tight clay that swells, and hold nearer 1.25 to 1.5 in clean, stable soil where you want to save fluid and spoil.
For equal conduits pulled as a tight cluster, the bundle diameter is a fixed multiple of one conduit's OD: two side by side is 2 times, three is about 2.15 times, four is about 2.41 times, and seven (a hex around a center) is 3 times. The calculator uses these packing ratios, then applies your backream factor to that envelope.
Friction and clearance. A hole cut to the exact product size binds — the pipe has nowhere to move and the drilling fluid has no annulus to carry cuttings out. Over-reaming gives room for the pull and for spoil to flow back, which is what keeps the product from getting stuck.
Easier, but not free. A larger hole lowers pull friction, but it also uses more drilling fluid, makes more spoil to manage, and takes longer to ream. The 1.5 times rule is the usual balance; go bigger only when the pull length or ground calls for it.
TrackOver's FiberOps tracks footage, reels, 811 mark-outs, permits, splices, and a bore log with depth of cover — plus crew-readable route maps from your KMZ designs and a live build link for the prime.