China high tensile hex bolt factory wholesale

High Strength Hexagon Bolts

Product Parameters

Product name: High Strength Hexagon Bolts

Material: Carbon Steel, Alloy Steel, Stainless Steel

Standard: ASME/ANSI B 18.2.1, IFI149,DIN931, DIN933, DIN960, DIN961, DIN558, ISO4014, ISO4017,

  ISO8765, ISO8676, JIS B1180

Measurement system: INCH, Metric

Size: 1/4”-3”, M5-M64 

Grade / Class: SAE J429 Gr.2, 5,8; ASTM A307Gr.A, Class 4.8, 5.8, 6.8, 8.8, 10.9, 12.9

Thread: M, UNC, UNF

Finish: Black Oxide, Zinc Plated(Clear/Blue/Yellow/Black),  H.D.G.  Y.Z.P.  Plain, Nickel,  Chrome

Description

High tensile steel bolts

Grade 8.8 high tensile steel is often referred to as the structural grade for bolts. It is the most common form of high tensile material and is usually stocked in plain finish or zinc. It can be plated in many other coatings.For high tensile steel grade 8.8, a torque wrench will be required for the tightening of said product. These products are built to last and work optimally under harsh usage and should be easily identifiable via a permanent marking on the head to allow the customer to differentiate them.

Grade 10.9 bolts are typically used in automotive applications and for bolting large, forged parts and are often made using carbon steel and boron steel. Socket and Countersunk buttons are commonly manufactured in this grade.

Grade 12.9 bolts, fasteners and fixings are for some of the heaviest jobs, such as securing engines and ensuring that drives are tamper proof.

The grade of the fastener doesn’t just determine how much stress that they can withstand, but also the kind of tool needed to be able to tighten them.

High-strength hex head screws cause lockup:

Internal cause analysis

1. When the bolts and nuts produced by the same material are assembled, the probability of thread locking increases.

2. The influence of thread precision, the external thread grade 6H and the internal thread 6H will increase the friction force. (Excessive fit) The external thread produced by our company adopts 6g (gap fit), and the large diameter of the thread is within the tolerance range. Lower limit.

3. The higher the content of copper Cu in the material composition, the higher the thread and the locking probability, but some fasteners have to use the material with higher copper content due to the deformation of the cold pier. The materials used by our company will cause the thread to lock the probability of locking from large to small; 302HQ≧304HC≧304

External cause analysis

1. If the product is not properly selected, make sure that the mechanical properties of the product meet the requirements of use (such as the tensile strength of the screw and the safe load of the nut) before use. In addition, the length of the screw should be selected properly, so that it is better to expose the nut to 1-3 thread after tightening.

2. The tooth pattern is rough or there is foreign matter sticking. If there are solder joints and other metal chips caught between the thread, it often leads to locking.

3. Excessive force or locking speed is too fast. Use torque wrench or socket wrench as much as possible to avoid using adjustable wrench or electric wrench. Because electric wrench often causes the locking speed to be too fast, the temperature rises rapidly and locks up.

4. The angle of the force application direction is unreasonable. The nut must be screwed perpendicular to the axis of the screw. Do not tilt.

Production equipment

Testing Equipment

Packaging details

Warehouse