Large Flat Metal Washers

The dimensional accuracy and flatness of Large Flat Metal Washers directly affect the distribution uniformity of bolt pretightening force. According to the ISO 2768 fine-level tolerance standard, for gaskets with an outer diameter greater than 100 mm, the outer diameter size deviation is controlled within plus or minus 0.3 mm, and the flatness does not exceed 0.05 mm to ensure that the large-area supporting surface is fully attached to the base material and avoid stress concentration caused by local bulges. At the same time, according to the ASTM E9 normal temperature compression test, when this type of gasket is subjected to a compressive stress of 200 MPa, the permanent deformation in the thickness direction is less than 0.01 millimeter. The corresponding elastic compression per square millimeter area can absorb an assembly gap of about 50 microns. This characteristic enables it to effectively compensate for the microscopic unevenness of the flange surface, thereby reducing the bolt bending stress and extending the fatigue life of the connecting pair.

 

 

In terms of installation torque control, the surface coating of large metal flat washers is closely related to the friction coefficient. According to the VDI 2230 systematic calculation criteria, when the gasket is treated with Dacromet coating, the friction coefficient with the steel bolt bearing surface is stable in the range of 0.10 to 0.15, which is about 40% lower than the 0.18 to 0.25 of ordinary phosphating treatment, so that the M20 bolt can obtain an axial pretightening force of about 110 kN when the tightening torque is 280 Nm. The data is verified through the torque-pretightening force measurement calibration. In addition, according to the ISO 9227 neutral salt spray accelerated corrosion test, the Dacromet coating has no red rust on the base after 800 hours of exposure, and the corrosion resistance life is more than double that of ordinary galvanized layers. It is especially suitable for heavy-duty steel structure connections in offshore or high-humidity environments, effectively reducing the frequency and cost of regular maintenance.

 

 

 

 

 

 

 

Obtain drawings from clients or produce drawings based on their samples or specifications.

The drawings, product raw materials, surface treatment, and other details are attested to by both parties.

 

 

 

 

 

Provide a quote, ensure that the order quantity is accurate, and include all relevant details,

such as the terms of payment, the terms of trade, the type of packaging, etc.

 

 

 

Follow the original drawings and samples exactly when producing the goods.

It was carefully packaged and delivered to the clients following a final inspection.

 

 

 

 

 

 

 

 

 

 

 

 

 

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