🔧 Welding & Machining Tools

RPM, feed rate and material removal for milling — including the radial chip thinning correction most calculators leave out entirely.

Tap drill sizes for UNC, UNF and metric threads — with the form tap hole, the torque cost, and why 75% thread is a convention rather than a target.

Torque specs for SAE and metric bolts from proof load — and what lubrication does to the answer, which is more than the grade does.

ISO 286 hole and shaft limits for the preferred fits — plus the thermal expansion term that quietly destroys interference fits and is in no fit table.

Flat patterns for sheet metal — bend allowance, deduction, tonnage and springback, with the K-factor tracking your radius instead of being guessed once.

Whether your brake and tooling can make the part — tonnage, tooling limits, off-centre derating, and the minimum flange that stops most jobs first.

Weight of bar, tube, plate and standard sections in 23 alloys — using published section masses, because the rectangle method loses the root fillets.

Duty cycle at any current, the amps your machine runs all day, cylinder life in arc hours, and the gas your hose dumps at every arc start.

Arc energy and net heat input against the limit for your material, plus deposition rate — and why slowing down reduces penetration rather than adding it.

Preheat and interpass temperature from carbon equivalent and COMBINED thickness — the number that makes a 12 mm fillet behave like 36 mm plate.

Throat, capacity and weld metal for fillet welds — and why rounding a size up buys 33% more strength for 78% more metal.

Build a weld symbol and read it back in plain English — including why the same symbol means opposite faces under AWS and ISO System A.

Tick what you can see and get the likely defects — with the pairs that look alike and need opposite fixes flagged before you make it worse.

Identify an unknown thread from a diameter and a pitch across UNC, UNF, metric and pipe — including why a half-inch NPT measures 0.840 inches.

Hole positions on a bolt circle and gauge block stacks for a sine bar — with the odd-count measuring problem and the accuracy that vanishes above 45°.

Gauge to thickness for steel, galvanised, stainless, aluminium and wire — and why 16 gauge spans a quarter depending on which metal you meant.

Why an uncompensated tab-and-slot joint is loose by twice the kerf, not once — and why the sheet usually varies more than the beam does.

Generates a kerf-compensated box as downloadable SVG — and shows why narrower fingers give more glue area, not less.

A power-by-speed grid is a third repeats, because the result depends on P/v — so cut a diagonal sweep instead, and get a real answer.

Packs your parts onto sheets and exports SVG — mixing sizes in a row saves a third of the material, rotation only 3.6 per cent.

Your bit is not what bends — the machine outflexes it 150 to one. What bit choice actually buys is chipload, through flute count.

What never to put in a laser and why — the rule behind the blacklist is chlorine, and you can test for it with a copper wire.