MechRef: Threads & Machining

MechRef is the mechanical engineering reference you carry in your pocket. Standards tables and calculators to solve problems on the shop floor, in the design office, or in class — without opening a manual.

WORKS OFFLINE. All data and calculations live inside the app: in the plant basement, on site, or wherever there's no signal, MechRef still works.

━━━ FREE MODULES ━━━
▸ THREADS
ISO metric coarse (M1–M76) and fine (M2–M64), plus UNC (#1–3") and UNF (#0–1-1/2").
Tolerance class 6g external and 6H internal.
For each size: nominal diameter, pitch, pitch diameter, minor diameter, thread depth and stress area.
Includes TAP DRILL: theoretical value and recommended for ≈75% engagement. No more hunting for a tap drill chart.
Based on ISO 724 and ISO 261.

▸ FITS & TOLERANCES
ISO 286-1 hole-basis system. Preset fits: H7/f7 running, H7/g6 sliding, H7/k6 transition, H7/p6 press, H8/f7 loose running and H11/c11 slack.
Enter the nominal diameter and get IT grade, ES/EI and es/ei deviations, max/min hole and shaft sizes, and maximum clearance or interference. With a tolerance diagram to see the fit at a glance.

▸ UNIT CONVERTER & CONSTANTS
Converter organized by discipline (Physics and Mechanics): pressure (Pa, bar, psi, atm), energy (J, kJ, kWh, BTU) and power (W, kW, hp, BTU/h), among others. 180+ conversions plus 65 physics and mechanics constants.

▸ AREAS & VOLUMES
Geometry for circle, rectangle, triangle, sphere, cylinder, cone and prism. Each shape with its diagram, input parameters and area, perimeter and volume results. Work in mm, m or inches.

━━━ PRO MODULES ━━━
▸ MORE THREAD STANDARDS
British: Whitworth BSW (1/4"–2") and BSF (3/16"–1-1/2"). Pipe: BSPP/G, BSPT/R (1/16–2) and NPT (1/16"–4"). Power screws: ISO trapezoidal (Tr 8–Tr 100), ACME (1/4"–3") and Stub ACME (1/2"–3").

▸ MACHINING — Milling, drilling and turning
Calculate cutting speed (Vc), RPM (N), feed per tooth (fz) or per rev (f), table feed (Vf), material removal rate (MRR) and cutting power (Pc).
Pick the workpiece and tool material and the app returns the recommended range. Includes cutting-speed tables by material (aluminum, mild steel, carbon steel, stainless steel, cast iron, brass, copper, titanium, Delrin, Teflon) and by tool (HSS, HSS-Co, carbide, coated carbide, CBN and ceramic). Work in mm or inches.

▸ GEARS — Module, pitch and gear ratios.
▸ SPRINGS — Compression, extension, torsion and leaf.
▸ SHAFTS & KEYS — Design by torque and bending, keys & keyways.
▸ BELTS & CHAINS — V-belt, flat belt, roller chain and timing belt: power and tensions.
▸ GEOMETRY & TRIGONOMETRY — Triangles, arc & sector, functions and polygons.
▸ PRO CONVERTER — Fluid mechanics and thermodynamics, with density and specific volume.

━━━ TRY PRO FREE FOR 7 DAYS ━━━
Start the trial from inside the app and use every Pro module for 7 days. No payment, no card, no auto-renewal: when it ends, Pro modules lock again and nothing is charged.

After that, Pro is a one-time purchase. No subscription, no monthly payments, no ads.

━━━ WHO IT'S FOR ━━━
- Lathe/mill operators and CNC machinists
- Toolmakers and industrial maintenance staff
- Design engineers and technical drafters
- Mechanical engineering and technical-school students

━━━ ALSO ━━━
- Smart search: type a term or size (M10, H7, cutting speed) to jump to the right module
- Reference-standards list (ISO, ASME, BS, DIN) by module
- "How to use" guide in every module
- History of your previous lookups and calculations
- Copy any result with one tap
- Light and dark themes

Developed by HRSoftware. Also available for Windows. Learn more at hrsoftware.ar/mechref