ASME B18.2.3.9M:2001 Metric Hex Head Flange Heavy Bolt combines a heavy hex head, flange bearing surface, and full-body shank design for metric joints that require high load capacity and dependable contact support.
The heavy head supports higher tightening force, the flange increases bearing area, and the shank contributes to joint rigidity and shear performance. This bolt is suitable for heavy machinery, construction equipment, steel-structure accessories, and high-load bracket fixing.
Grip thickness, hole clearance, surface hardness, and matching hardware should be considered together. Depending on corrosion exposure, zinc plating, hot-dip galvanizing, or other protective coatings can be selected to extend service life.

Dimensions unit: mm
| Thread size d | M5 | M6 | M8 | M10 | M12 | M14 | M16 | M20 | |
| P | Pitch | 0.8 | 1 | 1.25 | 1.5 | 1.75 | 2 | 2 | 2.5 |
| ds | Max. | 5 | 6 | 8 | 10 | 12 | 14 | 16 | 20 |
| Min. | 4.82 | 5.82 | 7.78 | 9.78 | 11.73 | 13.73 | 15.73 | 19.67 | |
| s | Max. | 8 | 10 | 13 | 15 | 18 | 21 | 24 | 30 |
| Min. | 7.64 | 9.64 | 12.57 | 14.57 | 17.57 | 20.16 | 23.16 | 29.16 | |
| e | Max. | 9.24 | 11.55 | 15.01 | 17.32 | 20.78 | 24.25 | 27.71 | 34.64 |
| Min. | 8.56 | 10.8 | 14.08 | 16.32 | 19.68 | 22.58 | 25.94 | 32.66 | |
| dc | Max. | 11.8 | 14.2 | 18 | 22.3 | 26.6 | 30.5 | 35 | 43 |
| c | Min. | 1 | 1.1 | 1.2 | 1.5 | 1.8 | 2.1 | 2.4 | 3 |
| k | Max. | 5.8 | 6.6 | 8.1 | 10.4 | 11.8 | 13.7 | 15.4 | 18.9 |
| b | L≤125 | 16 | 18 | 22 | 26 | 30 | 34 | 38 | 46 |
| 125<L≤200 | 22 | 24 | 28 | 32 | 36 | 40 | 44 | 52 | |
| L>200 | 35 | 37 | 41 | 45 | 49 | 53 | 57 | 65 | |
| Thread length b | - | - | - | - | - | - | - | - | |
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Better Fastener is a professional fastener enterprise specializing in the manufacturing of steel washers, stainless steel washers, spring washers and sealingwashers. Founded in 2001 as a washer factory, the company expanded into a comprehensive enterprise integrating washers, nuts, bolts, spring nuts and other fastener products in 2010.
The company positions itself as a provider of comprehensive one-stop services for customers, relying on technological R&D, industrial investment and trade distribution.
With an experienced professional team and a sound sales network, Better Fastener has achieved excellent sales performance in both domestic and foreign markets,and has grown into one of the competitive manufacturers and suppliers in China's industrial fastener industry.
Better Fastener is committed to becoming a trusted fastener supplier for customers with reliable product quality, reasonable prices and on-time delivery
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