全球紧固件标准完整比较。了解国际贸昜中螺栓、螺母、螺丝和垫圈的DIN、ISO、ASTM、ANSI和BS标准。
Understanding Fastener Standards Systems
Different regions use different fastener standards, which can cause confusion in international trade: DIN (Deutsche Industrie Norm): German standard, widely used in Europe and adopted internationally. Now largely harmonized with ISO standards. ISO (International Organization for Standardization): Global standard, adopted by most countries. ISO standards are the most widely recognized internationally. ASTM (American Society for Testing and Materials): American standard, primarily used in North America but recognized worldwide. ANSI (American National Standards Institute): Coordinates American standards, often adopts ASME/ANSI standards for fasteners. BS (British Standards): British standard, now largely aligned with European EN standards.
Head Marking Comparison
Head markings indicate fastener grade and manufacturer: Metric Hex Bolts (ISO/DIN): - 8.8: Two radial lines below grade marking - 10.9: Three radial lines - 12.9: Three radial lines with higher contrast Inch Hex Bolts (ASTM/ANSI): - Grade 5: Three radial lines - Grade 8: Six radial lines - Grade ASTM A325: 'A325' marking Understanding markings helps verify fastener grade at delivery.
| Metric Grade | Tensile Strength (MPa) | Equivalent ASTM Grade | Head Marking |
|---|---|---|---|
| 4.8 | 400 | Grade 2 | None or 4.8 |
| 8.8 | 800 | Grade 5 | 8.8 |
| 10.9 | 1000 | Grade 8 | 10.9 |
| 12.9 | 1200 | Grade B | 12.9 |
Thread Standards: Metric vs UNC/UNF
Thread standards differ between metric and inch systems: Metric Threads (ISO/DIN): - Designation: M + nominal diameter (e.g., M10) - Thread pitch: Distance between threads (e.g., M10x1.5) - Angle: 60 degrees Inch Threads (UNC/UNF/UNEF): - UNC: Unified National Coarse (standard for general use) - UNF: Unified National Fine (higher strength applications) - UNEF: Unified National Extra Fine (special applications) - Thread count: Threads per inch (e.g., 3/4"-10 UNC) China manufacturers typically produce metric threads as standard but can produce UNC/UNF upon request.
Common Standard Equivalents
Common fastener standards and their equivalents: Hex Bolts: - DIN 933 = ISO 4017 (full thread) - DIN 931 = ISO 4014 (partial thread) - ASTM A325 = ISO 4014 (high strength) Hex Nuts: - DIN 934 = ISO 4032 (standard hex nut) - DIN 985 = ISO 10511 (nylon insert lock nut) Washers: - DIN 125 = ISO 7089 (flat washer) - DIN 127 = ISO 7092 (spring lock washer) When ordering, specify the standard you require - most Chinese manufacturers can produce to any standard specification.