General of Project
The client sent us the drawing/Design, we will realize the design.
Quantity
200pcs
Material
35CrMo
Surface
Dacromet coating by NOF Metal Coating company, the salt spray test should be more than 500 hours.
Process
Forging+Machining+Word Stamping+Coating
The difficulty of the manufacturing:
- It is a big bolt, the head diameter is 50mm, the length is more than 150 mm, weight is higher than 1.2 kg.
- The word stamping on the surface should be very clear.
- The surface should be perfectly smooth without defects. This causes the problem of the hanging process of the coating, which needs a special hanging tool.
- All the tolerance should be within the scope of design, it is precision.
Project Process of the Batch
Stage 1: Sampling for one piece without surface coating
We protected the thread in this picture.
We sent these non-coating ball bolts and also the coated bolts for clients to check the size.
We found the problem, that the words are not in the right direction of the drawing.
The word’s direction should be 90 degrees off the flat surface, see above.
There is a dark mark on the top surface.
Stage 2: Correct the word direction
The order quantity is 200pcs. We manufacture all the quantity 200pcs of the forging screw ball bolt body. It is difficult to forge only a few sample quantities because of the material problem.
When we manufacture the forging body of all the ball screw bolts, we predicted that it may have some problems in future. So we make the plus tolerance of the height.
This gives us the possibility to correct the wrong word direction.
If we have the height margin, we remove the words directly and stamp again.
For some heights in which size is not enough, we can not use the above method. We will weld the material to fill the words, and then polish again. After the coating, there will be no appearance difference.
Stage 3- Resolve the Coating Mark problem
We also find the dark tint problem on the surface at the area of “3.5t”. It is the hanging fixture mark when we do the dacromat coating.
We improved the coating craft to resolve the problem.
Stage 4: The word “5mm” area is not clear!
After all, 200pcs is coated, and we found some of the bolts had a new problem. The word 5mm area is not clear.
We use the method mentioned above to do the work. We correct it for one process.
Finally!
This project lasted four months. Thanks to our Production Team(forging+coating+stamping), Technical Team, Quality Control Team and our Service Team. Because of you, we got a very nice job!
Perfect! Nice job!
