Gang-saw blades do not cut with a sharp edge — they reciprocate through the block while a fed abrasive slurry does the actual material removal by rolling/rubbing loose grit against the stone (three-body abrasion). The removal rate follows the same form as Preston's equation, widely used for lapping and abrasive machining:
dh/dt = Kp · P · V · g(grit)
P = F / (kerf · L) — contact pressure, MPa
V = 2 · Lstroke · f / 60 — mean reciprocating blade speed, m/s
g(grit) = sqrt(80 / mesh) — coarser grit (lower mesh #) removes stone faster
Blade wear follows the analogous Archard adhesive/abrasive wear law, wear rate ∝ P·V, so higher downforce and coarser grit that speed up cutting also burn through blades faster — the real trade-off a gang-saw operator balances. The saw's steel frame sags very slightly under load, so blades nearer the edge of the gang see a little less downforce than the centre blade (a documented effect in industrial gang sawing); the per-blade depth graph on the right shows that small spread.
- Blade spacing sets slab thickness directly: thickness = spacing − kerf. Tighter spacing yields thinner (more, but slower to cut) slabs.
- Grit size trades cutting speed against surface finish and blade life — coarse grit (#46) cuts fast and wears blades hard; fine grit (#220) is slow but gentle.
- Time is shown in "shift-hours" of simulated machine operation — the clock runs about 3600× faster than real time so a full pass finishes within a viewable demo.