#sheet-metal

Riveted-joint strength maths as an API, computed locally and deterministically — the shear, bearing and rivet-count numbers a structural, sheet-metal or aircraft fitter checks a riveted connection by. The shear-capacity endpoint gives the load a rivet group carries across its shanks = the rivet area (π/4·d²) × the shear strength × the number of rivets × the shear planes — a rivet in single shear is cut on one plane, in double shear (the centre plate of a butt joint with cover plates) on two, so it carries twice. The bearing-capacity endpoint gives the load the rivets can press against the sides of their holes before the plate crushes = the projected contact area (diameter × plate thickness) × the bearing strength × the number of rivets; thin plates fail in bearing long before the rivet shears, which is exactly why both must be checked — the joint strength is the lesser of the two. The rivets-required endpoint inverts it: the rivets a design load needs = the load ÷ the allowable load per rivet (area × allowable shear × planes), rounded up to a whole rivet, using the working shear (strength ÷ safety factor) not the raw value. Everything is computed locally and deterministically, so it is instant and private. Ideal for structural and sheet-metal estimating, mechanical-design and fastener tools, and engineering calculators. Pure local computation — no key, no third-party service, instant. Shank-shear and bearing only — also confirm edge tear-out and minimum pitch. 3 compute endpoints. For bolt preload and torque use a bolt-torque API; for thread geometry a thread API; for welded joints a welding API.

api.oanor.com/rivet-api

Sheet-metal bending maths as an API, computed locally and deterministically. The bend-allowance endpoint computes the bend allowance, bend deduction and outside setback for a single bend from the material thickness, the inside bend radius, the bend angle and the K-factor: the bend allowance is BA = θ·(r + K·t), the outside setback is OSSB = (r + t)·tan(θ/2) and the bend deduction is BD = 2·OSSB − BA, with the neutral-axis position reported too. The flat-length endpoint computes the flat blank length you need to cut: from a list of outside (mold-line) flange lengths, or two flanges, or a total, it subtracts the bend deduction for each bend. The kfactor endpoint lists typical K-factors by material — aluminium around 0.33, mild steel 0.44, stainless 0.45 — and estimates a K-factor from the inside-radius-to-thickness ratio. The K-factor can be given directly or chosen by material, and if the inside radius is omitted it defaults to the thickness. Lengths are unit-agnostic — the output matches whatever unit you supply. Everything is computed locally and deterministically, so it is instant and private. Ideal for sheet-metal CAD/CAM and press-brake tools, fabrication and unfolding apps, maker and prototyping projects, and manufacturing calculators. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is sheet-metal bend development; for the weight of the blank use a metal-weight API.

api.oanor.com/sheetmetal-api