Threaded Bolts - Stress Area
Calculate the tensile stress area in bolts according to UN/UNR or ISO 898-1 standards. The stressed area represents the weakest point in a bolt at the thread root.
UN and UNR Bolts Tensile Stress Area
Calculate stressed area using:
A = (π / 4) × (dn - 0.9743 / n)²
Where:
- A = stressed area (in²)
- dn = nominal bolt diameter (in)
- n = threads per inch (TPI)
ISO 898 Bolts Tensile Stress Area
Calculate stressed area using:
As,nom = (π / 4) × ((d2 + d3) / 2)²
Where:
- As,nom = nominal stress area (mm²)
- d2 = pitch diameter (mm)
- d3 = minor diameter (mm)