Work it out.
Calculators
Spindle speed from cutting speed
Skæredata (n = Vc·1000 / π·d)
Table feed and cutting time (milling)
Skæredata (Vf = fz·z·n)
Mass of round bar (stock blank)
Geometri + densitet (m = ρ·π·r²·L)
Drilling time (incl. point allowance)
Skæredata + borgeometri (DIN 338/345, spidshøjde ≈ 0,3·d)
Surface roughness Ra in turning
Fagteori.dk — teoretisk Ra ved drejning (Ra = f²/32r)
Minor diameter and drill size for tapping (metric)
ISO 68-1 / DIN 13 — metrisk ISO-gevind (60°)
Material removal rate in turning
Skæredata (Q = ap·f·Vc)
Thermal measurement uncertainty in precision measurement
DS/EN ISO 1 (referencetemperatur 20°C) + længdeudvidelseskoefficient
Tolerance zone (IT grade) to ISO 286
ISO 286-1:2010 (IT-tolerancegrader)
Number of passes in rough turning/milling
Geometri/planlægning (antal snit = radiel afvirkning ÷ maks. snitdybde)
Batch production time (setup + unit time)
Definition — produktionsplanlægning (T = T_opstilling + n·T_stk)
Mixing cutting oil (emulsion)
Producentdata (typisk 5–8% arbejdskoncentration, kontrolleres med refraktometer)
Chip weight and scrap value
IJ Recycling ApS — dagspris jernspåner (01/07-2026)
Taper angle/conicity in taper work
Geometri (konicitet C = (D−d)/L)
Tightening torque for a machine screw
VDI 2230 / bolte.dk — nøglefaktor K (vejledende)
Tank and vessel
Exact flat pattern
Funnel and hopper
Exact flat pattern
Bent bracket
Exact flat pattern
Edge-bent panel
Exact flat pattern
Rectangular elbow
Exact flat pattern
Square-to-round transition
Approximate flat pattern
Rectangle-to-rectangle transition
Exact flat pattern
Truncated cone and reducer
Exact flat pattern
Nozzle in a shell
Exact flat pattern
Dished end cap
Approximate flat pattern
Tee and lateral
Exact flat pattern
Breeches piece
Exact flat pattern
Segmented pipe elbow
Exact flat pattern
Screw conveyor flight
Approximate flat pattern
Flat plate, flange and blank
Exact flat pattern
Tank support — saddle, legs and skirt
Exact flat pattern
Rectangular duct, straight section
Exact flat pattern
Cooker hood and process extraction hood
Exact flat pattern
Tub with fall and drain
Exact flat pattern
Channel and trough with fall
Exact flat pattern
Part-cylindrical jacket
Exact flat pattern
Stair stringer
Exact flat pattern
Wheel arch repair panel
Exact flat pattern
Two-part valve cover
Exact flat pattern
Flange box
Exact flat pattern
Nozzle with tab collar on a flat wall
Exact flat pattern
Strip layout for a stamping die
Exact flat pattern
Cyclone and dust separator
Exact flat pattern
Five-pointed star
Exact flat pattern
Archimedean spiral
Exact flat pattern
Elliptical cone
Approximate flat pattern
Pipe-to-square transition
Approximate flat pattern
Orange-peel sphere
Approximate flat pattern
Spiral staircase
Exact flat pattern
Square tube cross
Exact flat pattern
Cable tray
Exact flat pattern
Box and tray
Exact flat pattern
Tools that work in all subjects
Whatever your programme is called, these tools calculate the same — Pythagoras, area, percentages and units are not tied to one trade.
- Pythagorasa² + b² = c²Find the missing side, set out a right angle, check whether a room is square, and find the space diagonal.
- Area and perimeterm²Rectangle, triangle, trapezium, circle and composite shapes — area and perimeter.
- Volume and surface aream³ · lBox, cylinder, cone, sphere, pyramid, prism, pipe and frustum — also in litres.
- Percent%Percentage of, how many per cent, percentage change, discount and VAT.
- Scale and ratios1 : 50From drawing to reality, area and volume to scale, the rule of three and dividing in a ratio.
- Unit convertermm ↔ mFrom mm to km, Pa to bar and kB to GB — with the unit staircase.
- Time calculations and the clockt : minTime between two clock times, add time, and 1.75 h = 1 h 45 min for the timesheet.
- Slope and fall% · ° · 1:xFall from level to level, in per cent, per mille, degrees and mm per metre — and the height difference.
- Material consumption including wastem² + %Boards, paint, battens at c/c spacing and packs — for a composite surface or a whole room, with waste.