Introduction of High strength bolts:
High-strength bolts are a type of fastener commonly used in the construction of steel structures, such as bridges, buildings, and industrial facilities. These bolts are designed to provide a strong, reliable connection between structural steel members, ensuring the overall stability and integrity of the structure.
High strength bolts transmit external forces by applying pretension and friction.
High strength bolts are generally used for permanent connections.
High-strength bolt connection has the advantages of simple construction, good mechanical performance, disassembly, fatigue resistance, and no loosening under dynamic load, so it is a promising connection method.
Class 8.8 high strength bolt construction torque value reference table | ||||||||
S.Q | Bolt specification | Bolt performance class | Standard value of construction pre-tension (KN) | Torque coefficient (standard deviation less than or equal to 0.010) | Initial torque (N*m) | Final torque (N*m) | Measured torque coefficient | Final torque (N*m) |
1 | M16 | 8.8s | 75 | 0.11~0.15 | 78 | 132~180 | 0.121 | 145 |
2 | M20 | 8.8s | 120 | 0.11~0.15 | 156 | 264~360 | 0.123 | 295 |
3 | M22 | 8.8s | 150 | 0.11~0.15 | 215 | 363~495 | 0.125 | 413 |
4 | M24 | 8.8s | 170 | 0.11~0.15 | 265 | 448.8~612 | 0.125 | 510 |
5 | M27 | 8.8s | 225 | 0.11~0.15 | 395 | 668.3~911.3 | 0.125 | 759 |
6 | M30 | 8.8s | 275 | 0.11~0.15 | 536 | 907.5~1237.5 | 0.125 | 1031 |
Class 10.9 high strength bolt construction torque value reference table | ||||||||
S.Q | Bolt specification | Bolt performance class | Standard value of construction pre-tension (KN) | Torque coefficient (standard deviation less than or equal to 0.010) | Initial torque (N*m) | Final torque (N*m) | Measured torque coefficient | Final torque (N*m) |
1 | M16 | 10.9s | 110 | 0.11~0.15 | 114 | 193.6~264 | 0.122 | 215 |
2 | M20 | 10.9s | 170 | 0.11~0.15 | 221 | 374~510 | 0.12 | 408 |
3 | M22 | 10.9s | 210 | 0.11~0.15 | 300 | 508.2~693 | 0.126 | 582 |
4 | M24 | 10.9s | 250 | 0.11~0.15 | 390 | 660~900 | 0.125 | 750 |
5 | M27 | 10.9s | 320 | 0.11~0.15 | 562 | 950.4~1296 | 0.125 | 1080 |
6 | M30 | 10.9s | 390 | 0.11~0.15 | 761 | 1287~1755 | 0.125 | 1463 |
Features of high-strength bolts:
Material Composition:
High-strength bolts are typically made of alloy steel, such as ASTM A325 or ASTM A490 steel, which have higher tensile strengths compared to standard mild steel bolts.
The higher strength steel allows the bolts to withstand greater loads and stresses without compromising the connection.
Tensile Strength:
High-strength bolts have a minimum tensile strength of 120 ksi (825 MPa) for ASTM A325 bolts and 150 ksi (1035 MPa) for ASTM A490 bolts.
Evercross Steel Bridges Overview :
EVERCROSS STEEL BRIDGE SPECIFICATION | ||
EVERCROSS STEEL BRIDGE | Bailey bridge(Compact-200, Compact-100, LSB, PB100, China-321,BSB) Modular bridge( GWD, Delta, 450-type,etc), Truss Bridge,Warren bridge, Arch bridge, Plate bridge,Beam bridge,Box girder bridge, Suspension bridge,Cable-stayed bridge, Floating bridge,etc | |
DESIGN SPANS | 10M TO 300M Single span | |
CARRIAGE WAY | SINGLE LANE, DOUBLE LANES,MULTILANE,WALKWAY,ETC | |
LOADING CAPACITY | AASHTO HL93.HS15-44,HS20-44,HS25-44, BS5400 HA+20HB,HA+30HB, AS5100 Truck-T44, IRC 70R Class A/B, NATO STANAG MLC80/MLC110. Truck-60T,Trailer-80/100Ton,etc | |
STEEL GRADE | EN10025 S355JR S355J0/EN10219 S460J0/EN10113 S460N/BS4360 Grade 55C AS/NZS3678/3679/1163/Grade 350, ASTM A572/A572M GR50/GR65 GB1591 GB355B/C/D/460C,etc | |
CERTIFICATES | ISO9001, ISO14001,ISO45001,EN1090,CIDB,COC,PVOC,SONCAP,etc | |
WELDING | AWS D1.1/AWS D1.5 AS/NZS 1554 or equivalent | |
BOLTS | ISO898,AS/NZS1252,BS3692 or equivalent | |
GALVANIZATION CODE | ISO1461 AS/NZS 4680 ASTM-A123, BS1706 or equivalent |