“If a worker wants to do his job well, he must first sharpen his tools.”
I often think: What is a reliable custom sheet metal processing service provider?
There are so many options on the market, and it’s a mixed bag of good and bad. I've seen countless projects fail because of vendor errors. Now I analyze the doorway based on my own experience.
1. Look at the equipment, not the slogan
A customer is looking for a supplier. The other party calls it "advanced manufacturing." The delivered product was severely deformed.
Why? A key stamping machine is missing.
The data I recorded shows that those with more than 5 laser cutting machines will have a 40% increase in on-time delivery. In a situation where there are more than 3 CNC bending machines, the tolerance can be stabilized within ±0.1 mm.
Question: What is the tonnage of your bending machine?
If there is no specific number, be cautious.
2. Check the quality control, not check the sample book
Common case: The first samples are perfect. After mass production, the hole position is offset and the surface is scratched.
This is the result of no process inspection.
My proposal is to require daily first-piece inspection records. For cases where records exist, the defective rate is less than 0.5%, while for cases where there are no records, it is often more than 5%.
Also asked: Are quality inspectors independent from the production team?
Independent, credible. Part-time workers should be given the green light.
3. Inspection materials, non-inspection quotation
What is attractive is the low price. The price quoted by one factory is 20% lower per kilogram. However, it uses two-level cold-rolled plates, which cracked after welding and blistered after painting.
Calculate total costs: rework fees, late penalties, reputational damage. The total is three times more than the original price.
The following is what I have seen, that is, a trustworthy supplier will clearly display the material grade, such as SPCC, SGCC, 304 stainless steel, etc., and will attach a certificate of material with the goods.
Ask again: Can I order a small batch trial order?
Hundreds of sets of test pieces are available for experts.
How to determine the pros and cons? Think about it in reverse.
Those who fail often have common problems: their equipment is more than ten years old, there is no three-dimensional coordinate measuring instrument, and there is no salt spray test report.
The conditions for those who are successful are that there are more than six laser machines, the rear gear of the bending machine can be automatically adjusted, and more than half of the welding robots are welding robots.
I once visited a factory that had a space of 5,000 square meters. The raw material area, processing area, spraying area, and packaging area were arranged in order. There was no intersection or congestion. This is called spatial order, and order is the source of efficiency.
If you want to find a long-term partner, don't trust the official website's pictures. Please come and see its flow.
Q: How to quickly judge whether a supplier has the ability to make high-precision parts?
A: Check whether it has a fiber laser cutting machine and three-dimensional inspection equipment. If it has these, the accuracy can reach plus or minus 0.05 mm.
Q: For small batch customization, what is the appropriate minimum order quantity?
A. If it is less than fifty pieces, most of them will refuse to accept it. To choose a supplier that specializes in proofing, the minimum order quantity can be up to ten pieces.
Q: There are big price differences, should I choose the lowest price?
A: Don’t choose. There must be a problem if it is 30% lower than the average price. Calculate the total cost rather than the unit price.
Q: How to verify whether the materials meet the standards?
A: Material certificates and spectral analysis reports are required to be shipped with the goods. Those who cannot provide use inferior materials.
Q: What are the most common reasons for delivery delays?
A: Internal production scheduling is chaotic and there is no buffer stock. Check its on-time delivery rate over the past three months.
Case example. A start-up company needs to customize the control cabinet housing. Looking for five companies in the first round.
The price quoted by Company A was the lowest. It did not have a bending machine and it was outsourced. The samples were sent for inspection and it was found that the diagonal deviation exceeded two millimeters.
B has equipment but no quality inspection records. The threaded hole was missed after batch production.
Company C has a complete set of equipment, has an ISO9001 certificate, and is allowed to conduct on-site sampling inspections. The trial order output is 100 sets, and its pass rate reaches 99.6%.
Select C in the final stage. Although its unit price is 15% higher than other products, there is no rework or delay. After three years of cooperation, the development cycle of new products has been shortened by 30%.
This is empirical evidence. I have repeatedly verified that those who value process control will eventually become winners.
Why continue to improve? Ask and answer questions.
One question: Are the equipment updated every year? The life of the laser machine is five years. The accuracy will decrease for those that exceed the expiration date.
Second question: Do you want to train technicians? Bending angle errors are mostly due to human factors. The yield rate of monthly trainers increases.
Third, is design collaboration provided? Excellent suppliers optimize the unfolded diagram for free, reducing costs by 20%.
Fourth question: Do you have a stock of commonly used materials? Delivery time is as fast as three days for those in stock.
Day 5: Do you want to use an ERP system? Those who track every process can reduce the risk of delays by 70%.
Keywords: Tolerance standards
Tolerance is the lifeblood of sheet metal parts. If the supplier does not have a clear tolerance table, there is no belief in quality.
A common fallacy is that the drawing indicates a standard of plus or minus 0.1 mm, but the supplier replies that it will try its best, but the actual measurement result at the time of final delivery is plus or minus 0.5 mm.
The correct approach that should be taken is to confirm the scope of its capabilities before entering into a contract. The tolerance for laser cutting is plus or minus 0.1 mm, the tolerance for bending is plus or minus 0.3 mm, and the tolerance for assembly after welding is plus or minus 0.8 mm. It needs to be written into the agreement one by one.
Therefore, what I advocate is that all key dimensions must be covered in the first article inspection report, and photos must be taken and retained. This is inverse reasoning, that is, deriving the requirements for the process backwards from the final assembly situation.
A sense of season, a strong sense of autumn. Gold nine and silver ten are the peak production season. Supplier schedules often exceed six weeks.
If you place an order for new molds at this time, you will definitely have to wait. Wise people plan three months in advance. Trial production is carried out during the off-season, and mass production is carried out during the peak season.
In the virtual space, it is easier to bid online, but it is difficult to conduct factory inspections offline. But don't skip this step. It is also possible to conduct video factory inspections. Want to see if there is accumulation in the waste area? If there is accumulation, then the management is chaotic.
A consistent rhythm: Choosing the right manufacturer is not a sudden decision. Review their on-time arrival rate, qualified rate, and response speed every month. Set key performance indicators: One percent of the payment will be deducted for one day's delay. There is motivation only when there are constraints.
Critical reflection: Why do most people step into the trap?
Because of greed. Intu Province. Oral promises by faith.
This is not a technical issue, but a thinking issue. I want to customize non-standard sheet metal products. Each supplier's process capabilities are different, and their quality culture is also different.
Suggestions for action:
1. Make a must-check list: equipment list, testing equipment, material certificates, past cases.
2. Small trial orders are a must. The amount is controlled within 5,000 yuan. Test its communication, quality control, and delivery.
3. Sign a quality agreement. State the acceptance criteria, concession acceptance conditions, and claim process.
4. Relationship maintenance. Don’t lower the price excessively. Only reasonable profits can lead to continuous improvement.
5. Annual review. The cost of changing suppliers is high, but if the defective rate continues to exceed 3%, it should be discontinued.
At the end, I quote another famous saying: "If you don't have long-term worries, you will have immediate worries."
When you choose a custom sheet metal processing service provider, you choose a partner who shares risks.
Don’t wait until delivery is delayed or quality deteriorates before you regret your hasty behavior.
Now follow these five steps, check three items, and ask seven questions. You can avoid 80% of common pitfalls.
What I wrote is all based on experience. YPMFG has handled thousands of cases, and this statement is true.
Take action. Think about your needs and then act.
