Qingdao Haosail Machinery Co., Ltd.

1. Raw Material Inspection

Quality starts with the material.

Before production, incoming steel materials are checked according to the required specifications. Material grade, dimensions and relevant documentation are verified before the material enters the production process.

Using consistent raw materials helps us maintain stable mechanical performance and product quality from batch to batch.

2. Controlled Forging

Forging is one of the most important stages in shackle manufacturing.

During the forging process, the steel is formed under controlled conditions to achieve the required shape and structural integrity. Proper forging helps reduce potential defects and ensures that the shackle body has a consistent structure.

Our production team pays close attention to the forging process so that different batches can maintain consistent quality.

3. Heat Treatment

After forging, heat treatment plays a critical role in achieving the required mechanical properties.

The heat treatment process is carefully controlled according to the product requirements. Proper treatment helps the shackle achieve the necessary combination of strength and toughness for lifting applications.

This stage is essential because the performance of a shackle cannot be judged by appearance alone.

4. Precision Machining

After heat treatment, key components are machined to the required dimensions.

Critical areas such as holes, threads, pin dimensions and contact surfaces are checked to ensure proper dimensional accuracy. Good machining quality is important not only for assembly, but also for the correct operation of the finished shackle.

5. Surface Treatment

Surface quality is another important part of our inspection process.

After the required surface treatment, shackles are checked for visible defects, surface condition and overall appearance. The appropriate surface finish also helps protect the product during storage, transportation and use.

6. Assembly & Marking

Before final inspection, the shackle body and pin are assembled and checked for proper fit.

Product markings are also verified. Important information such as size, Working Load Limit (WLL) and other required identification marks should be clear and consistent with the product specifications.

Clear marking helps customers identify and use the product correctly.

7. Final Inspection & Testing

Final inspection is the last checkpoint before shipment.

Our QC team checks key dimensions, appearance, assembly and markings. Depending on the product specification and customer requirements, relevant testing and inspection documents can also be provided.

The purpose is not simply to find defective products, but to confirm that the finished shackles meet the required specifications before they leave our facility.

8. Careful Packing Before Shipment

Quality control does not stop after inspection.

Once the products have passed QC, shackles are properly sorted and packed according to size and order requirements. Good packing helps reduce the risk of damage during transportation and makes it easier for customers to receive, count and store their products.

Quality Is a Process, Not a Final Check

For us, quality is not created at the final inspection stage. It is built step by step—from raw material selection and forging to heat treatment, machining, testing and packing.

By controlling each stage of production, we aim to provide shackles with consistent quality and reliable performance for our customers around the world.