Timber Bolt Joint Designer to AS 1720.1

Verified by the CalcTree engineering team on August 21, 2024
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This calculator designs timber bolt joint connections. It checks the capacity of bolt joints connecting two timber members, subject to applied shear or tension forces in the bolts.
All calculations are performed in accordance with AS 1720.1-2010.
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CalculationAssumptions
Timber Member Properties
Joint Configuration
Modification factors
Design Capacity
﻿﻿Phi
:0.80​
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Capacity reduction factor
﻿﻿Q_sk
:9180N​
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Characteristic strength per joint 
﻿﻿N*
:20 kN​
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﻿﻿N_d,j
:22.62kN​
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﻿﻿Utilisation
:88%​
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﻿﻿Check
:✅ ​
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Bolt joint capacity
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ExplanationThe strength of bolted timber joint connections is largely dependent on the effective timber thickness, ﻿beff​
.
Code Parameters and EquationsAS 1720.1 categorises a connection type into either "type 1" or "type 2" for the purpose of design. The code also prescribes minimum dimensions for the bolt set-out.
👉Unlike nails and screws, bolts are fastened on both sides and therefore bolts are only used in "side grain" (not "end grain") applications.
Type 1 Joint
Type 2 Joint
Minimum Spacing, Edge and End Distance
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Related ResourcesTimber Nailed Joint Designer to AS 1720.1
Timber Screwed Joint Designer to AS 1720.1
Timber Beam Calculator to AS1720.1
Timber Column Calculator to AS1720.1
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