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Product Overview
Metric Grade 8.8 bolts are high-strength carbon steel fasteners manufactured to ISO 898-1 and EN 15048 standards. These bolts are quenched and tempered to achieve a minimum tensile strength of 800 MPa and a yield strength of 640 MPa, making them the industry standard for structural and machinery bolting in general engineering, construction, and automotive applications.
Grade 8.8 bolts are widely specified for their balance of strength, ductility, and cost-effectiveness. They are available in a wide range of diameters and lengths, with thread forms conforming to ISO metric coarse and fine series. Surface finishes include plain, zinc-plated, hot-dip galvanized, and black oxide for corrosion protection in various environments.
| Material | Carbon Steel, Quenched & Tempered |
| Grade | 8.8 |
| Material Standard | ISO 898-1 / EN 15048 |
| Bolt Standard (Metric) | DIN 931 / DIN 933 / ISO 4014 / ISO 4017 |
| Bolt Standard (Inch) | BS 3692 (for inch series) |
| Thread Form | ISO Metric Coarse / Fine |
| Diameter Range | M5-M72 |
| Tensile Strength | 800 MPa min |
| Yield Strength | 640 MPa min |
| Hardness | 22-34 HRC |
Complete the Fastener Set
Technical Data
| Size (M) | Pitch (mm) | A/F (mm) | Head Ht (mm) | Min L (mm) | Max L (mm) |
|---|---|---|---|---|---|
| M6 | 1.0 | 10 | 4.0 | 10 | 200 |
| M8 | 1.25 | 13 | 5.3 | 12 | 250 |
| M10 | 1.5 | 17 | 6.4 | 16 | 300 |
| M12 | 1.75 | 19 | 7.5 | 20 | 400 |
| M16 | 2.0 | 24 | 10.0 | 25 | 500 |
| M20 | 2.5 | 30 | 12.5 | 30 | 600 |
| M24 | 3.0 | 36 | 15.0 | 40 | 600 |
| M30 | 3.5 | 46 | 18.7 | 50 | 800 |
| M36 | 4.0 | 55 | 22.5 | 60 | 1000 |
| M42 | 4.5 | 65 | 26.0 | 80 | 1000 |
| M48 | 5.0 | 75 | 30.0 | 100 | 1200 |
| M56 | 5.5 | 85 | 35.0 | 120 | 1500 |
| M64 | 6.0 | 95 | 40.0 | 140 | 2000 |
| M72 | 6.0 | 105 | 45.0 | 160 | 2000 |
| Standard | Covers | Thread |
|---|---|---|
| DIN 931 | Hex bolts, partial thread | Metric |
| DIN 933 | Hex bolts, full thread | Metric |
| ISO 4014 | Hex head screws, partial | Metric |
| ISO 4017 | Hex head screws, full | Metric |
| BS 3692 | Hex bolts, inch series | Inch |
| EN 15048 | Non-preloaded structural bolts | Metric |
| Material Standard | Requirement |
|---|---|
| ISO 898-1 | Mechanical properties |
| EN 10204 3.1 | Mill test certificate |
| EN 15048 | CE marking for structural |
| ISO 4042 | Surface coatings |
Material Chemistry
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.25-0.55 |
| Manganese (Mn) | 0.50-1.65 |
| Phosphorus (P) | 0.035 max |
| Sulfur (S) | 0.035 max |
| Boron (B) | 0.003 max |
| Iron (Fe) | Balance |
Fastener Performance
| Bolt Size | Dry (Nm) | Lubricated (Nm) | Clamp Load (kN) |
|---|---|---|---|
| M12 | 81 | 65 | 45 |
| M16 | 200 | 160 | 90 |
| M20 | 400 | 320 | 140 |
| M24 | 690 | 550 | 205 |
| M30 | 1350 | 1080 | 320 |
| M36 | 2350 | 1880 | 460 |
| M42 | 3600 | 2880 | 630 |
| M48 | 5200 | 4160 | 830 |
Industry Applications
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