Steel · Connections: moment & splices

Extended end plate (4-bolt unstiffened) calculator

Bolt rows either side of the tension flange share the flange force; plate checked as a T-stub; compression-side bolts take shear.

Standard: AS 4100 Cl 9.3 · plastic bolt-row distribution (simplified)

Inputs in the worked example

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

Input	Value	Unit
Design moment M*	260	kNm
Design shear V*	120	kN
Beam (or haunch) depth	460	mm
Beam flange thickness	14.5	mm
Bolt centre to flange face pf	45	mm
Fillet weld leg	10	mm
Effective plate width per bolt p	90	mm
Bolt size	M24
Bolt category	8.8/TB
Plate grade	Grade 250 plate
End plate thickness	25	mm

Result	Value	Unit
Bolt diameter df	24.00	mm
Bolt tensile strength fuf	830.0	MPa
Tensile stress area As	353.0	mm²
Core area Ac (threads)	324.0	mm²
Shank area Ao	452.0	mm²
Plate yield stress fy (AS/NZS 3678)	250.0	MPa
Plate tensile strength fu	410.0	MPa
Outer row lever arm d − tf/2 + pf + tf/2	497.8	mm
Inner row lever arm d − 1.5tf − pf	393.3	mm
Bolt tension M/(2(h0 + h1))	145.9	kN
φNtf	234.4	kN
Effective bending length m = pf − 0.8 s	37.00	mm
Plate thickness required √(2 T m/(φ fy p))	23.09	mm
Shear per compression-side bolt	60.00	kN
φVf	133.4	kN

Diagram for the worked example

Bolt diameter df = CHOOSE(4,12,16,20,24,30,36) = 24 mm
Bolt tensile strength fuf = IF(3=1,400,830) = 830 MPa
Tensile stress area As = CHOOSE(4,84.3,157,245,353,561,817) = 353 mm²
Core area Ac (threads) = CHOOSE(4,76.2,144,225,324,519,759) = 324 mm²
Shank area Ao = CHOOSE(4,113,201,314,452,707,1018) = 452 mm²
Plate yield stress fy (AS/NZS 3678) = CHOOSE(1,IF(25<=8,280,IF(25<=12,260,250)),IF(25<=8,320,IF(25<=12,310,IF(25<=20,300,280))),IF(25<=12,360,IF(25<=20,350,340))) = 250 MPa
Plate tensile strength fu = CHOOSE(1,410,430,450) = 410 MPa
Outer row lever arm d − tf/2 + pf + tf/2 = 460+45-14.5/2 = 497.75 mm
Inner row lever arm d − 1.5tf − pf = 460-1.5*14.5-45 = 393.25 mm
Bolt tension M/(2(h0 + h1)) = 260*1000/(2*(497.75+393.25)) = 145.9 kN
φNtf = 0.8*353*830/1000 = 234.39 kN
Effective bending length m = pf − 0.8 s = 45-0.8*10 = 37 mm
Plate thickness required √(2 T m/(φ fy p)) = SQRT(2*145.9*1000*37/(0.9*250*90)) = 23.091 mm
Shear per compression-side bolt = 120/2 = 60 kN
φVf = 0.8*0.62*830*324/1000 = 133.38 kN

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