High Strength Anchor Bolt
Wind turbine anchor bolt raw material is 42CrMoA and other equivalent materials. It is purchased from large and qualified steel mills. Each steel round bar went through ultrasonic flaw detection before delivery. According to GB/T 4162 standard, reaches Class A level. LongTeng guarantee high strength anchor bolts supplied can meet or even higher than the technical specifications required in bidding documents.
Our high strength anchor bolts for wind turbine are manufactured following strict standard production process: anchor bolt is heat treated and then threaded: anchor bolt is tested after heat treatment, then peeled and drawing is processed to the specified medium diameter size. Peeling process can remove oxide scale and decarburization layer generated during heat treatment; and the last is screw thread.
Note: The middle part of wind turbine anchor bolt is not machined, it is one-time forming and thread precision is better.
Patent for High Strength Anchor Bolt
High Strength Wind Turbine Anchor Bolt Production Process:
Production Process Flow
Purchase raw materials according to plan (designated steel mill materials and grades) → Raw material Inspection → rough straightening → heat treatment (medium frequency induction heat treatment) → inspection (performance test) → peeling and fine alignment (100% ultrasonic flaw detection, fluorescent magnetic particle inspection, etc.) →Unloading→Machining (Chamfering)→Coded→Thread Rolling→Inspection (Threading Precision Gauge, Medium Diameter Micrometer, etc.)→ Anchor Bolt Tension Detection→ Anchor Bolt Anticorrosion Treatment (Dakro, coated according to customer requirements) Grease + heat shrinkable tube, etc.) → inspection → packaging → storage.
Anchor Bolt Test after Production:
Tensile Test: We make 100% tensile test to steel bars according to client’s request, tensile strength is 70% of the yield strength.(A bit higher than actual tensile strength).The elongation or re-condensation within ≤±0.02mm/m.
Anti-Corrosion Test: We use anti-corrosion grease+anti-corrosion belt +PVC tube+sealing nut to achieve the purpose. After 1000 hours’ salt spray test, there will be no corrosion on the products’ surface.
Anchor Cage Bolt Assembly Parts:
Dimension of Class 10.9 Anchor Bolt - Longteng
|Anchor BOLT Grade 10.9|
|D Nom||Diameter at smooth part||Pitch||Cross Section||Yield force||Ultimate force|
Dimension of Class 8.8 Anchor Bolt - Longteng
|Anchor BOLT Grade 8.8|
|D Nom||Diameter at smooth part||Pitch||Cross Section||Yield force||Ultimate force||Weight/meter|
Mechanical Properties of Available Anchor Bolt Grades
|Grade||Dia||Tensile Strength Rm/MPa||2% Elongation Limit RP 0.2/MPa||Stress Under Proof Load SPf/MPa||Elongation after fracture A/%||Reduction oF Area after Fracture Z/%||Rockwell Hardness /HRC||Bolt Length mm||-40 ℃ Impact Absorb Energy K/J|
Our anchor bolt products have super high yield strength(up to 1100 MPa) and tensile strength(up tp 1220 MPa). Regarding impact energy, our grade 8.8 anchor bolt everages 60J , grade 10.9 everages 35J which means our products performance much higher than standard requirements.
Recognized Steel Grades for Anchor Cage Bolts
|Anchor Bolt Steel Standard||Steel Grade&Tensile Strength|
|ISO 4014||Grade 8.8|
|ASTM A615 / A615M||Grade 75 (690 MPa [100 ksi] minimum tensile strength)|
|ASTM A722 / A722M||(1035 MPa [150 ksi] minimum tensile strength)|
|ASTM A193 / A193M||Grade B7 (860 MPa [125 ksi] minimum tensile strength)|
Chemical Composition Comparsion of Anchor Cage Bolt Rod
|Country||Chemical Composition Comparsion of Anchor Cage Bolt Raw Material|