CNC Reference Tables & Conversion Charts
The numbers you reach for every day. Every table cross-checks at least two independent sources (usually ISO + ASTM + a national standard like GB or JIS). If a value disagrees across sources we say so, and explain which one to use when.
How to use this section.
These are look-up pages, not articles. Open one, find your row, take the number. Each page lists its source standard at the top so you can cite it in your own drawing, quote, or report.
Hardness & Material Properties
- Hardness Conversion Table (HRC / HB / HV / HRA / HRB)Side-by-side equivalent values per ASTM E140 and ISO 18265, with notes on which conversions are exact vs. approximate
- Material Density TableDensity of 80+ common CNC materials (steel, aluminum, titanium, copper, plastics), g/cm³ and lb/in³
- Young’s Modulus, Poisson Ratio & CTEElastic modulus, ν, and coefficient of thermal expansion for structural and tooling materials
Threads & Fasteners
- Tap Drill Sizes (Metric & UNC/UNF)M1.6–M48, #0–1″, full tap drill with cut vs form tap columns per ASME B1.1 and ISO 2306
- Pipe Threads (NPT, BSPT, BSPP)Taper vs parallel, sealant rules, cross-reference between ASME B1.20.1 and ISO 7 / ISO 228
- Fastener Torque Chart (8.8 / 10.9 / 12.9)Recommended tightening torque by size and grade, dry vs lubricated, per ISO 898-1 and VDI 2230
- Wire & Sheet Gauge (AWG / SWG / BWG ↔ mm)Conversion table for wire and sheet metal gauge numbers, including the differences between American, Imperial, and Birmingham systems
Surface, Tolerance & Fit
- Surface Roughness Ra / Rz / N-GradeRa in μm and μin, Rz conversion, ISO 1302 N1–N12 grade numbers, typical process capability
- IT Tolerance Grades (IT01–IT18)ISO 286 fundamental deviations, IT5–IT12 numerical values by nominal size
- Common ISO Fits (H7/g6, H7/h6, H7/p6...)Clearance, transition, and interference fits — deviation tables and which application each one suits
- Process-achievable TolerancesEconomic precision for turning, milling, drilling, grinding, EDM — what each process can hold in normal production
Grade Equivalents
- Steel Grade Equivalents (GB / ASTM / EN / JIS)Chinese GB, US ASTM/SAE, European EN, and Japanese JIS designations for common carbon, alloy, stainless, and tool steels
- Aluminum Grade EquivalentsAA / ISO / EN / GB / JIS designation equivalents for 6061, 7075, 2024, 5052, and other CNC alloys
- Copper & Brass Grade Equivalents (CDA / EN / GB / JIS)C11000, C36000, C17200 designations across the major naming systems
Unit Conversion
Source hierarchy.
When sources disagree, our order of preference is: ISO → ASTM/ASME → regional (DIN, JIS, GB) → manufacturer datasheet → textbook. We document every disagreement inline so you can decide for your application.