Engineering reference charts.
Lookup tables for working engineers. Torque values by bolt grade, hardness across every common scale, surface finish achievable by each manufacturing process. Cited values per ISO and ASTM standards. Free, no signup.
Live charts
Bolt torque chart by grade and lubrication
Metric (M5–M30) and imperial (1/4"–1") bolt torque tables for ISO grades 4.8 / 5.8 / 8.8 / 10.9 / 12.9 and SAE Grades 2 / 5 / 8. Dry, lubricated, and stainless variants. Computed from T = K × D × F per ISO 898-1.
Drill size chart — tap drill, clearance, ANSI/ISO
Metric tap drill (M1–M48 coarse and fine), UNC and UNF tap drill, clearance drill per ISO 273 (close/normal/loose), number drills #1–#80, letter drills A–Z, NPT pipe tap drill, Helicoil tap drill.
Hardness conversion chart
Rockwell C, Rockwell B, Vickers, Brinell, Knoop, and approximate tensile strength conversions per ASTM E140. Steel ranges, non-ferrous metals, and Indian engineering grades (EN8, EN24, EN36, EN9, EN353) production hardness.
ISO 286 fits chart — H7/g6, h6, k6, n6, p6, r6, s6
Hole-basis and shaft-basis fit values with worst-case clearance and interference per ISO 286-1. Tolerance grades IT5–IT11, achievable IT by manufacturing process, and 12-fit selection guide by application.
ISO 286 fits visualizer (interactive)
Drag the diameter slider, click any fit preset (H7/g6, H7/k6, H7/p6, etc.), watch shaft and hole tolerance bands shift live on an SVG diagram. Live worst-case clearance / interference readout and fit-category verdict pill.
Drill and tap failure troubleshooter
Tap broke? Oversize threads? Chip welding? Decision-tree walks symptom → context → diagnosis. Material-specific fixes for stainless, aluminium, mild steel, hardened steel. Covers 8 failure modes that account for 90%+ of shop-floor drilling/tapping problems.
6g vs 6h thread tolerance comparison
External thread classes 6g (with allowance, for plated production fasteners) vs 6h (zero allowance, for ground threads and gauges). Side-by-side comparison, fundamental deviation table M3–M30, standard combination guide, common mistakes.
Surface finish by process
Typical and best-achievable Ra values for every major process — casting, forging, milling, turning, drilling, grinding, honing, lapping, EDM, electropolishing. ISO N grades (N1–N12) and Ra-to-Rz conversion factors.
In progress
Aluminium alloy properties comparison
Tensile, yield, hardness, density, machinability, weldability, corrosion resistance for 1100, 2024, 5052, 6061, 6063, 7075 — the most-used wrought aluminium alloys in Indian manufacturing.
Steel grade comparison — Indian, SAE, ISO
Cross-reference for EN8, EN9, EN19, EN24, EN36, EN353 vs SAE 1045, 4140, 4340, 8620, ISO equivalents. Heat treatment, hardness, applications, machinability.