What RoHS for PCBA means ?

How to choose a Chinese supplier ?

Since 2010, China is the world’s main manufacturing hub. Almost all manufactured parts are made with components at least partially produced in China. The fact that so many companies do work with Chinese suppliers doesn’t make it easier to identify reliable ones.

Is China still a good place to buy from ?

Cost of manufacturing in China

In spite of the increase in production costs, China has succeeded in keeping an overall cost advantage over other countries. This resilience is partially due to the fierce competition between Chinese suppliers.

For a given product, there will be tenths or hundreds of Chinese suppliers, often located close to one another and with very similar products, as the last factories to open where often opened by former employees of the first ones.

Naturally, the exacerbated competition is good for buyers that can use it to pressure down on supplier’s prices. The downside of it is that it is hard to identify which one will be the best match if you are not only looking for price but also for quality. This difficulty is enhanced by the plethora of offers by trading companies (also more commercially active and English speaking) that tops the offer of the already numerous factories.

Cost of shipping between China and Europe

Since the sanitary crisis logistics costs between China and Europe have soared, in some cases by more that 1000% ! It cannot be denied that this increase have an impact for the sourcing of low added value manufacturing parts. Nonetheless, logistics costs increase also impacted all other countries in the World, while China relied on the high productivity of it’s ports to contain this increase. The result being that China was able to keep logistic costs competitiveness compared to other countries closer to Europe.

In these conditions, how can I be sure to have access to the good Chinese supplier for my product ?

It is important to act according to a methodology, which we propose in three phases:

  1. – Supplier research phase
  2. – Comparison & pre-selection phase
  3. – Suppliers Background Checking & final choice

The supplier research phase is rather simple, as one just need to browse what one is looking for, use specialized websites (Alibaba, made-in-china, global sources…), or search specialized fair listings where one can always find a fair share of Chinese suppliers.

The next step is to compare the known technical offer/ capabilities of suppliers, their pricing and response time. Following this comparison, a short list of 2 to 3 suppliers at max should emerge.

You  then need to evaluate the credit you can give to this suppliers with background checking : documents (license),  address, factory or trading company, percentage of production sub-contracted. It is here quite convenient to use a standard questionnaire and then conduct some verification. You may also require 2/3 of them to provide samples to check quality and reactivity, Even if a little costly, it may be worth it and prepare you for a backup plan.

In which language can I communicate with a Chinese supplier ?

Surprisingly, many Chinese while having very poor oral English communication skills are able to communicate in relative good English by written. They are indeed relying on online translation tools, but most of them can also understand and write a simple English. We so advise simple written English communication, avoiding long and complex sentences and double-checking that information is well understood.

Supports for choosing good suppliers in China.

Needless to say, following this procedure takes time and a little bit of knowledge about doing business in China is needed in order to avoid usual Chinese suppliers tricks. Furthermore, if the size of the order or the complexity of the parts needs it, supplier visit or third party audit/inspection should be considered seriously. Read more

Incoterm: What do you need to know?

How to use International Commerce Terms (Incoterms)? You just got an offer from a supplier based abroad. And the transportation conditions mention DAP, DDP, EXW… or similar terms? What does that mean, and how to deal with it? What are the Incoterms? Suppose your company trades internationally or ships or receives shipments from an overseas […]

What is an OEM?

What is the meaning of MOQ?

What is the difference between PCB and PCBA ?

Lost Wax Casting Products

Lost wax casting, also known as water glass investment casting or ‘cire perdue’ (French), is a process that involves pouring metal alloys into a wax mold to create a pattern. Silver, gold, brass, and bronze are the most common metals used in this process. It is one of the oldest metal-forming techniques, dating back 6000 years, and is still commonly used for making jewelry, dental implants, and sculptures. Investment casting, in its industrial form, is a popular way to make precision metal parts and prototypes in engineering and manufacturing. Lost wax casting provides precision parts in the order of a tenth of a millimeter.

Advantages of Lost Wax Casting

  1. Lost Wax Casting can manufacture and render thin-wall, complex shapes, near net-shapes, delicate floral forms, difficult-to-machine materials, multi-working procedures, and multiple components into one piece.
  2. Any material can be used in investment casting, and production capability is more versatile. Aluminum, titanium alloys, magnesium alloys, copper alloys, cobalt, steels of all kinds, and nickel-based heat-resistant alloys, and hard materials are all acceptable casting materials.
  3. In comparison to other casting methods, investment casting can achieve the goal of a short working time and low cost by avoiding the need for numerous working procedures, large mechanical processes, and low productivity and material waste to produce high-cost components.
  4. Material waste and mass production can be reduced by lost wax casting.
  5. Only lost wax casting allows for the production of a wide range of products across various industries. An example of a larger-scale product that can be manufactured using investment casting is turbine blades with complex shapes for the power generation industry. Another example is the firearm industry, where investment casting is used for smaller precision parts such as firearm triggers, receivers, and hammers.

The Process

  1. An original model is made from wax, clay, or other material.
  2. This model is then cast and polished to produce a master pattern.
  3. The mold is filled with molten wax through injection or pouring.
  4. Sprues are added to the wax and joined to create a tree-like structure that allows molten metal to fill the cavity later.
  5. Then it is dipped in a silica slurry or placed in a flask of liquid investment plaster.
  6. The flask is put upside down in a kiln after the investment material has dried, melting the wax and leaving a negative cavity in the form of the original model.
  7. Melted metal is then poured into the cavity, with the metal being drawn in by gravity or vacuum pressure.
  8. The investment mold is quenched in water to remove the refractory plaster after the molten metal has cooled somewhat.

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Lost Wax Foundry

The lost wax casting subcontracting from China uses carbon steel, stainless steel, aluminum, and nonferrous metals. 3-4 axis machining centers, surface treatment centers with custom packing facilities are included in the services. For the production of relatively simple parts of metals, sand casting foundries are also functional. The shell foundry helps to optimize the production of small and medium-series precision parts. Customers can manufacture parts in China to save money while maintaining a high level of quality.

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Shell Foundry Parts

7 steps guide for buying technical parts from China

CNC machining center workshop

Based on our 20 years experience, you’ll find our guide to purchase techincal parts from China.

Some tools, tips and process to follow for successfull subcontracting in China written by our General Manager. Read more