Why is it easy for stainless steel wire mesh to break during production?

During the production of stainless steel expanded metal, wire breakage often occurs, rendering the product unusable. Every expanded metal factory has likely experienced this; it's not exclusive to stainless steel, as carbon steel, aluminum, and other materials can also suffer from this issue, although it's relatively more common with stainless steel. Why does wire breakage occur in stainless steel expanded metal?

Anyone who has purchased expanded metal knows it's a mesh-like metal sheet. Each sheet's four sides are connected by rectangular metal bars. These bars forming the mesh are what we call the wires of the expanded metal, and their breakage results in quality issues. The raw materials for expanded metal can be stainless steel, aluminum, carbon steel, galvanized steel, copper, etc. Mesh openings are often diamond-shaped, but also include other shapes such as fish scale, hexagonal, and fish mouth. Regardless of the material or hole type, the wire is a crucial element. Based on years of production experience, several key reasons for wire breakage during stainless steel expanded metal production include:

1. Material

Even with stainless steel, 201 grade is completely unsuitable for producing expanded metal, while 304, 316, and 430 grades are suitable. This is because the different elemental content in stainless steel results in variations in rigidity and ductility, impacting the outcome. The diamond-shaped hole ratio is typically 2:1; exceeding this ratio generally makes stainless steel expanded metal production impossible.

2. Dies

Dies are the cutting tools. Expanded metal can be thought of as using a tool to cut the steel sheet into individual bars, which are connected. Newly made dies are in optimal condition. After some use, cutting becomes difficult, mainly manifesting as wire breakage. This is due to wear and dulling of the dies. The solution is to replace the dies or resharpen them. It's similar to kitchen knives; when they become dull, they need sharpening or replacing. Continuing to use them is inefficient, unsafe, and may lead to deformed cuts.

3. Wire Size

During production, the numerical control (NC) console requires inputting the dimensions of the feedstock, i.e., the wire width of the finished expanded metal. This dimension directly affects the weight and Price of the expanded metal. Larger feedstock requires greater pressure during punching and shearing, and even greater force to stretch the material into the desired position. This forceful mechanical action on the steel sheet may exceed its limit, leading to wire breakage.

4. Raw Material Thickness

Steel punching machines, or expanded metal machines, come in different tonnage capacities, such as 63T or 100T, representing the impact force. Different tonnage capacities handle different material thickness ranges. Thicker steel requires greater impact force. For the same machine, thicker steel makes production more strenuous. Sometimes, significant machine vibrations are noticeable, increasing the likelihood of wire breakage.

5. Mesh Opening Size

Mesh opening size is relative to wire size. Excessive size in either direction can cause wire breakage. For example, using a 40*20mm die to punch 1.0mm thick 304 stainless steel, achieving a 2.0mm wire width is extremely difficult without breakage. However, adjusting to 1.5mm, a difference of only 0.5mm, significantly improves the feasibility.

In summary, multiple factors can contribute to wire breakage in expanded metal production. These factors are not independent and are often relative. Theoretically, it's not simply one or two factors causing this. A comprehensive consideration is required. However, for products with determined Specification, one or two factors might be the primary cause. Paying attention to these points ensures smooth production.