Inside the app
A closer look.
About this app
Made for a clear purpose.
Boltspan: Joint Design is a focused, fully on-device app. A transparent bolted-joint calculator for preload scatter, torque, joint stiffness, load fraction, separation, proof margin, fatigue, and tightening sequences.
KEY FEATURES - Metric thread stress-area library - Torque-preload scatter envelope - Bolt/joint stiffness model - Separation and proof margins - Sequence and inspection worksheet - Editable complete sample and local project persistence - CSV input plus local PDF and data export - Fifty-two original offline reference plates
ONE-TIME AND PRIVATE - One paid download; no subscription or in-app purchase - No account, advertising, analytics, tracking, or developer-operated backend - Core features and bundled content work offline - Work remains on device unless you deliberately share or export it through an Apple system interface
Engineering screening only. Confirm material, lubrication, thread engagement, embedment, temperature and governing code.
