High-Strength Twisted Shear Round Head Bolts - China Factory Suppliers for Steel Structures
Production parameter
| 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 |
| dk | Min | 21 | 27 | 34 | 38.5 | 43 | 48 | 52 | 66 |
| k | nominal | 8 | 10 | 13 | 14 | 15 | 17 | 19 | 23 |
| Max | 8.8 | 10.8 | 13.9 | 14.9 | 15.9 | 17.9 | 20 | 24 | |
| Min | 7.2 | 9.2 | 12.1 | 13.1 | 14.1 | 16.1 | 18 | 22 | |
| 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 | |
| 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 |
| Max | 16 | 18 | 21 | 21.5 | 24 | 26 | 31 | - | |
| r | Min | 1.2 | 1.2 | 1.5 | 1.5 | 1.5 | 2 | 2 | 2 |
| R | nominal | 18 | 20 | 22 | 23 | 25 | 27 | 30 | 36 |
| Lg Max | - | - | - | - | - | - | - | - | |
Production description
Steel structure torsion shear bolt is a high-strength bolt and also a type of standard component. Steel structural bolts are divided into torsion shear high-strength bolts and large hexagonal high-strength bolts. Large hexagonal high-strength bolts belong to the high-strength grade of ordinary screws, while torsion shear high-strength bolts are an improved type of large hexagonal high-strength bolts for better construction. The large hexagonal steel structural bolt consists of one bolt, one nut, and two washers. Twist shear steel structural bolts consist of one bolt, one nut, and one washer. On general steel structures, the required steel structural bolts are grade 8.8 or above, as well as grades 10.9 and 12.9, all of which are high-strength steel structural bolts. Sometimes, bolts on steel structures do not require electroplating.
The length of a torsion shear high-strength bolt is the length from the lower support surface of the screw head to the cut at the end of the screw. The torsion shear high-strength bolt has a plum blossom head at the tail of the screw, and a special wrench is used to tighten the nut during construction. The torque when the plum blossom head is broken is the standard torque. They all belong to friction type high-strength bolts and can be replaced, but torsion shear type high-strength bolts do not require torque calculation and are easy to ensure torque, which can avoid the phenomenon of inability to ensure final tightening torque due to calculation errors or using ordinary wrenches instead of torque wrenches.
The size of the hexagonal head of the steel structure large hexagonal bolt connection pair is different from that of the general outer hexagonal bolt connection pair. The size of the hexagonal head of the steel structure large hexagonal bolt connection pair is larger than that of the ordinary hexagonal bolt product. Therefore, the steel structure large hexagonal bolt connection pair can also be called the steel structure large hexagonal bolt connection pair. The steel structure large hexagonal bolt connection pair is mainly used for the construction of industrial and civil buildings, railway bridges, highway bridges, pipeline bridges, tower and mast structures, boiler frames, boiler steel structures, large-span industrial plants, high-rise civil buildings, various towers, light steel structures, lifting machinery, and other steel structure connection buildings.
Each set of steel structure large hexagonal bolt connection pair includes one high-strength steel structure large hexagonal bolt connection pair GB/T 1228, one high-strength nut GB/T1229 for steel structures, and two high-strength washers GB/T1230 for steel structures, all of which are manufactured in the same batch. The standards for large hexagonal bolt connection pairs in steel structures include: GB/T1228-2006 Steel Structure Large Hexagonal Bolt Connection Pairs, GB/T1229-2006 High Strength Large Hexagonal Nuts for Steel Structures, GB/T1230-2006 High Strength Washers for Steel Structures, and GB/T1231-2006 Technical Conditions for Large Hexagonal Bolt Connection Pairs, Large Hexagonal Nuts, and Washers for Steel Structures.
When assembling the connecting pair of large hexagonal bolts in steel structures, the chamfered side of the washer under the bolt head should face the bolt head; When constructing the connection pair of large hexagonal bolts in steel structures, a torque wrench is required, which requires a large operating space and needs to be completed in two parts: initial tightening and final tightening. The construction is relatively more complicated compared to torsion shear bolts; Quality inspection also requires torque inspection, requiring professional equipment and quality inspectors.