Material weight
Rectangular bar, plate, or blank. Pick the alloy and enter the envelope.
Enter the three dimensions.
Volume × density. Ignores radii, holes, and machining allowance.Calculators
Quick answers for early decisions.
Metric
Imperial
Unit conversion
The conversions that come up most often reading a shop drawing.
Enter a value.
Exact factors: 25.4 mm/in, 0.45359237 kg/lb, 6894.757 Pa/psi.Bolt torque
Target tightening torque from bolt size, preload, and thread condition.
Enter diameter and preload.
T = K · D · F. The K factor is empirical and scatters widely — treat the result as a starting point, not a specification.Sheet metal bend allowance
Arc length through the bend, for laying out a flat pattern.
Enter angle, radius, and thickness.
BA = (π/180) · A · (R + K·T). Always confirm the K factor against your fabricator’s own test bends.Thin-wall hoop stress
Circumferential stress in a cylinder under internal pressure.
Enter pressure, diameter, and wall.
σ = P·D / 2t, valid only where D/t > 20. Not a code calculation — pressure equipment must be designed to ASME VIII or the governing code.Beam deflection
Mid-span deflection of a simply supported rectangular beam under a centre point load.
Enter load, span, and section.
δ = FL³/48EI, I = bh³/12. Elastic only, self-weight excluded, solid rectangle.Reference
Numbers worth not looking up twice.
| Material | kg/m³ | lb/in³ |
|---|---|---|
| Mild steel | 7850 | 0.284 |
| Stainless 304 | 8000 | 0.289 |
| Cast iron | 7200 | 0.260 |
| Aluminium 6061 | 2700 | 0.098 |
| Brass | 8500 | 0.307 |
| Copper | 8960 | 0.324 |
| Titanium Gr. 5 | 4430 | 0.160 |
| UHMW polyethylene | 940 | 0.034 |
| Thread | Pitch | Tap drill | Clearance |
|---|---|---|---|
| M3 | 0.50 | 2.50 | 3.4 |
| M4 | 0.70 | 3.30 | 4.5 |
| M5 | 0.80 | 4.20 | 5.5 |
| M6 | 1.00 | 5.00 | 6.6 |
| M8 | 1.25 | 6.80 | 9.0 |
| M10 | 1.50 | 8.50 | 11.0 |
| M12 | 1.75 | 10.20 | 13.5 |
| M16 | 2.00 | 14.00 | 17.5 |
| M20 | 2.50 | 17.50 | 22.0 |
Use these as planning estimates, not design verification. Every calculator here uses a simplified textbook model, with its assumptions stated underneath it. They are good for sizing a first idea, sanity-checking a supplier quote, or deciding whether something is worth modelling properly. They are not a substitute for code calculations, finite element analysis, or review by the engineer of record on your project. If a number here is going to be relied on, send us the case and we will check it properly.
Project intake checklist
What to send for a faster quote.
Photos
Overall views, closeups, interfaces, labels, and failure points.
Measurements
Critical dimensions, bolt patterns, clearances, and known tolerances.
Existing files
PDFs, DWG, STEP, STL, sketches, manuals, and old drawings.
Deadline
Tell us what decision or fabrication date the design must support.
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