THE FOUR-CORNER WORKSHOP
Clampcraft
Tighten in passes. Keep the cover together.
Choose four identical bolts and a wrench setting. Tap a corner to bring it to that torque. The flexible cover relaxes the two neighboring bolts, so revisit corners in a diagonal sequence. Pass the proof test with enough clamp and grip, even preload, and no overstressed bolt.
First job: M6, grade 8.8, 8 Nm. Try A → C → B → D, then repeat until the spread is below 12%. A single pass will not suffice.
Parts & wrench
Changing the bolt set rebuilds the cover. Each click sets the selected bolt to the wrench torque; it does not add that torque.
Model, units & source
Torque-to-preload uses EngiCalc’s schraube thread geometry, friction and combined tensile/torsional utilization. Its reference torque is Nmm, converted to Nm here. Applied torque scales the reference preload linearly at fixed thread friction; peak utilization records every tightening, including an over-tightening later undone only with Undo or a rebuild.
Neighbor relaxation is an original simplified game rule, not an engineering prediction. Each added preload removes the stated fraction from adjacent corners. External corner loads subtract directly from clamp; grip is interface friction times positive remaining clamp. This omits gasket creep, joint stiffness, fatigue and bolt-load sharing. Educational puzzle, not a joint design certification.
Source: EngiCalc Core, MIT, 0 stars observed, October 2026 commit. Actual maschinenelemente.js retained with globalThis wrapper adaptation. Original jobs and GPT metal/gasket/workbench materials. License.