Bolt Shear Stress
Calculate the shear stress in transversely loaded bolts, τ = F ÷ (n·A), from the total shear force F (N), the number of bolts (or shear planes) n and each bolt's area A (mm²). Unlike tensioned joints (where the bolt is tightened and the load is axial), in SHEAR joints the bolts resist a transverse force tending to slide one part over another (as in steel structural connections, splice plates, flanges under lateral load). The force is distributed among the bolts and each works in shear — hence the stress is force divided by the number of bolts times the area. There can be SINGLE shear (one shear plane) or DOUBLE shear (two planes, when the bolt passes through three plates), doubling capacity. The area used depends on whether the shear plane passes through the threaded part (use the tensile area) or the smooth shank (nominal-diameter area). Shear stress is compared with the bolt material's shear strength (typically ~0.6 of tensile strength). In structures, bearing-type (bolt in shear/bearing) and slip-critical (preload friction transmits load without bolt shear) connections are distinguished — this formula covers shear resistance. Enter the shear force, the number of bolts and the area.
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Tensão de cisalhamento em parafuso
A tensão de cisalhamento em parafusos solicitados transversalmente é τ = F ÷ (n·A), a partir da força cortante total F, do número de parafusos (ou planos de corte) n e da área de cada parafuso A. Diferente das uniões tracionadas (em que o parafuso é apertado e a carga é axial), em uniões de cisalhamento os parafusos resistem a uma força transversal que tende a deslizar uma peça sobre a outra (como em ligações estruturais de aço, talas de emenda, flanges sob carga lateral). A força é distribuída entre os parafusos e cada um trabalha ao corte — daí a tensão ser a força dividida pelo número de parafusos vezes a área. Pode haver corte simples (um plano de cisalhamento) ou duplo (dois planos, quando o parafuso atravessa três chapas), o que dobra a capacidade. A área usada depende de se o plano de corte passa pela parte rosqueada (usa-se a área de tensão) ou pela parte lisa do corpo (área do diâmetro nominal). A tensão de cisalhamento é comparada com a resistência ao cisalhamento do material do parafuso (tipicamente ~0,6 da resistência à tração). Em estruturas, distinguem-se ligações por contato (o parafuso trabalha ao corte/esmagamento) e por atrito (a pré-carga gera atrito que transmite a carga sem o parafuso cisalhar) — esta fórmula trata da resistência ao corte. Informe a força cortante, o número de parafusos e a área.
Related Tools
Bolt Count for Shear
Calculate the number of bolts needed to resist a shear force, n = F ÷ (A·τ_adm), from the total shear force to transmit F (N), each bolt's area A (mm²) and the material's allowable shear stress τ_adm (MPa). In structural and mechanical connections loaded in shear (beam splices, truss connections, flanges under lateral load, splice plates), the force is distributed among several bolts, each working in shear. The number needed is the total force divided by one bolt's shear capacity (area × allowable stress). The result is rounded up, and in practice a quantity is adopted that also meets minimum bolt spacing, edge distance and connection symmetry criteria. This calculation is the basis of designing bolted connections in steel structures (where it competes with welding) and in machines: it sets how many bolts and of what diameter are needed. There are other checks in the same connection: plate BEARING (contact pressure on the hole wall, which can tear the plate before the bolt shears), edge tear-out and the plate's own net-section strength (minus the holes). But bolt shear is the starting point. Enter the shear force, each bolt's area and the allowable stress.
Bolt Tensile Stress
Calculate the tensile stress in a bolt, σ = F_b ÷ A_t, from the total bolt tensile force F_b (N) and the tensile stress area A_t (mm²). It is the basic strength check of a tensioned bolt: the acting stress (force over resisting area) must be below the material strength with a safety margin. The force F_b is the total load the bolt carries — in a preloaded joint, the preload plus the fraction of external load reaching the bolt (F_i + C·P). The resulting stress is compared with the proof strength S_p (the limit up to which the bolt can be loaded without permanent deformation — typically 85-90% of yield) or the ultimate strength, per the criterion. The bolt strength class (marked on the head: 8.8, 10.9, 12.9 metric; or SAE grades 2, 5, 8) sets these allowable stresses — a class 8.8 bolt has a proof strength of 580-600 MPa, a 12.9 reaches ~970 MPa. Verifying σ does not exceed the allowable, considering preload and service load, is essential: overloaded bolts yield (losing preload) or break. With the fatigue and separation checks, it defines the tensioned joint's safety. Enter the total bolt force and the tensile area.
Beam Shear Stress
Computes max shear stress for a rectangular beam under a shear force.
The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.