Single-disc force and stack force/travel per DIN 2092 Almen-Laszlo formula
Almen-Laszlo formula per DIN 2092: F = (4E/(1−ν²)) · (t⁴/(K1·De²)) · (s/t) · [(h0/t − s/t)(h0/t − s/2t) + 1], with K1 = (1/π) · ((δ−1)/δ)² / [((δ+1)/(δ−1)) − 2/lnδ] and δ = De/Di. h0 = l0 − t is the cone height. Working deflection limited to 75% of h0 per DIN 2093. Parallel nesting multiplies force; series stacking multiplies travel. E ≈ 206000 MPa, ν ≈ 0.3 for spring steel (51CrV4).