EN 14399-10 (CS Bolt):2018 High Strength Preload HRC System Tension Control Countersunk Head Bolt is used where structural joints require controlled preload, low head projection, and high load capacity at the same time.
The HRC tension-control system supports more controlled installation results, while the countersunk head reduces protrusion. It is suitable for steel structures, bridge components, platform panels, and nodes requiring clearance or surface flatness.
This product is usually managed as part of a matched assembly, so consistency among bolts, nuts, and washers is important. Installation should consider friction-surface preparation, tightening sequence, and final inspection to ensure preload and structural safety.

Dimensions unit: mm
| Thread size d | M12 | M16 | M20 | M22 | M24 | M27 | M30 | M36 | |
| P | Pitch | 1.75 | 2 | 2.5 | 2.5 | 3 | 3 | 3.5 | 4 |
| b | L≤125 | 30 | 38 | 46 | 50 | 54 | 60 | 66 | 78 |
| 125<L≤200 | - | 44 | 52 | 56 | 60 | 66 | 72 | 84 | |
| L>200 | - | - | 65 | 69 | 73 | 79 | 85 | 97 | |
| ds | Max. | 12.7 | 16.7 | 20.84 | 22.84 | 24.84 | 27.84 | 30.84 | 37 |
| Min. | 11.3 | 15.3 | 19.16 | 21.16 | 23.16 | 26.16 | 29.16 | 35 | |
| dk | Max. | 24 | 32 | 40 | 44 | 48 | 54 | 60 | 72 |
| Min. | 23.16 | 31.16 | 39 | 43 | 47 | 53 | 58.8 | 70.8 | |
| k | Nominal | 8 | 10 | 13 | 14 | 16 | 17.5 | 19.5 | 23 |
| Max. | 8.75 | 10.75 | 13.9 | 14.9 | 16.9 | 18.4 | 20.55 | 24.05 | |
| Min. | 7.25 | 9.25 | 12.1 | 13.1 | 15.1 | 16.6 | 18.45 | 21.95 | |
| r | Max. | 1.6 | 1.6 | 2 | 2 | 2 | 2.5 | 2.5 | 2.5 |
| Min. | 1.2 | 1.2 | 1.5 | 1.5 | 1.5 | 2 | 2 | 2 | |
| db | Nominal | 7.7 | 11.3 | 14.1 | 15.4 | 16.8 | 19 | 21.1 | 25.4 |
| Max. | 8 | 11.6 | 14.4 | 15.7 | 17.1 | 19.3 | 21.4 | 25.7 | |
| Min. | 7.4 | 11 | 13.8 | 15.1 | 16.5 | 18.7 | 20.8 | 25.1 | |
| dc | Min. | 8.36 | 12.43 | 15.6 | 17.06 | 18.65 | 21.13 | 23.5 | 28.5 |
| F1 | Min. | 11 | 13 | 15 | 15.5 | 16 | 19 | 21 | 25 |
| F2 | Max. | 16 | 18 | 20 | 21 | 21.5 | 24 | 26 | 31 |
| Lg Max. | - | - | - | - | - | - | - | - | |
| Thread length b | - | - | - | - | - | - | - | - | |
ABOUT US
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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