Steel · Connections: bolts & welds

T-stub in tension with prying (Thornton) calculator

Available bolt tension of a T-stub flange including prying; thickness for no prying, α′ and Q.

Standard: AISC Steel Construction Manual Part 9 prying model (φ = 0.9)

Inputs in the worked example

The live calculator starts with these values; change any of them and every result, check and diagram updates instantly.

Result	Value	Unit
b′ = b − d/2	35.00	mm
a′ = min(a, 1.25b) + d/2	50.00	mm
ρ = b′/a′	0.700
δ = 1 − d′/p	0.756
tc = √(4 B b′/(φ p Fu))	25.60	mm
α′ = ((tc/t)² − 1)/(δ(1 + ρ))	1.21
Q	0.686
Available tension per bolt B·Q	111.8	kN

Diagram for the worked example

b′ = b − d/2 = 45-20/2 = 35 mm
a′ = min(a, 1.25b) + d/2 = MIN(40,1.25*45)+20/2 = 50 mm
ρ = b′/a′ = 35/50 = 0.7
δ = 1 − d′/p = 1-(20+2)/90 = 0.75556
tc = √(4 B b′/(φ p Fu)) = SQRT(4*163*1000*35/(0.9*90*430)) = 25.597 mm
α′ = ((tc/t)² − 1)/(δ(1 + ρ)) = ((25.597/16)^2-1)/(0.75556*(1+0.7)) = 1.214
Q = IF(1.214<0,1,IF(1.214<=1,(16/25.597)^2*(1+0.75556*1.214),(16/25.597)^2*(1+0.75556))) = 0.68595
Available tension per bolt B·Q = 163*0.68595 = 111.81 kN

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For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.