A stainless steel wire mesh filter looks simple, but a reliable one is the result of a controlled, multi-step process. Every step affects whether the finished part holds its rating, seals against bypass and survives in service. Understanding how these parts are made helps buyers write better specifications and judge supplier quality. Here is the journey from raw mesh to finished filter.
1. Material selection
It starts with the right stainless wire — typically 304 for general use or 316L where corrosion resistance matters. The wire is woven into cloth at a defined mesh count, wire diameter and weave (plain, twill or Dutch), or supplied as perforated or expanded sheet for coarser forms. The weave and wire diameter — not just the mesh number — determine the true opening, so a good part starts with a fully specified cloth backed by a material certificate.
2. Cleaning
Woven mesh carries drawing lubricant and metal fines left over from weaving. Quality manufacturers ultrasonically clean the cloth before fabrication so these contaminants are not trapped in the finished filter — a critical step for fuel, hydraulic, food and pharmaceutical applications where any shed particle is a defect.
3. Cutting to shape
Blanks are cut with CNC or fiber-laser equipment for dimensional repeatability. Laser cutting gives clean, burr-light edges on discs, strips and complex profiles and seals the cut edge so fine wires do not fray. Stamping with dedicated tooling is used for high-volume identical parts.
4. Forming
Flat blanks become three-dimensional parts. Cloth is rolled into cylinders and tubes, stamped into filter discs and caps, pleated to increase filtration area, or pressed into strainer baskets using dedicated tooling. Forming has to hold tight dimensions so the finished element fits its housing without gaps that would let fluid bypass.
5. Welding
Seams and end fittings are joined by resistance spot welding, seam welding, TIG or plasma welding depending on the design. Simple screens may be spot-welded; leak-critical elements use continuous seam, TIG or laser welds for a durable, sealed joint. Consistent, validated weld parameters are what keep a filter from bypassing under pressure — a weak weld is the most common cause of field failure.
6. Sintering (for rigid multi-layer parts)
When maximum strength and a fixed pore structure are required, stacked mesh layers are diffusion-bonded in a vacuum furnace into a single rigid plate. Sintered mesh can then be cut, pleated and welded without changing its rating, which is why it is used in high-pressure hydraulic and polymer-melt filters.
7. Finishing and passivation
Edges are deburred, and where required the part is passivated (typically to ASTM A967, using citric or nitric acid) to remove free iron and restore the chromium-oxide layer that gives stainless its corrosion resistance. Electropolishing is added for medical, food and marine parts that need an ultra-clean, smooth surface.
8. Inspection and documentation
Finished parts are checked for dimensions, mesh integrity and weld quality using calipers, micrometers, height gauges and, where the rating is critical, bubble-point testing to verify the actual pore size. For OEM programs this is backed by ISO 9001 process control, material certificates (e.g. EN 10204 3.1), full dimensional reports and PPAP submissions. See our Capabilities and Quality & Certifications pages.
How to judge a supplier
Ask how they clean the cloth, how they validate welds, whether they can passivate and document material traceability, and whether they can supply first-article and PPAP paperwork. A shop that can answer all of these clearly is one that will deliver a consistent, leak-tight filter batch after batch.
Frequently Asked Questions
How is a leak-tight filter cylinder made?
By TIG, laser or seam welding the longitudinal seam and end caps, then inspecting each weld — resistance spot welds alone can bypass under high pressure.
Why does cleaning matter so much?
Residual lubricant or metal fines can shed into the filtered fluid; ultrasonic cleaning before assembly prevents this and is essential for fuel, food and pharma parts.
What documentation can you provide?
Material certificates, dimensional inspection reports, and full PPAP submissions for OEM programs.
Can you make parts to our drawing?
Yes — from a single prototype to mass production, built to your drawing with full documentation.
Have a custom filter to make? Send your drawing or sample and we will quote it. Request a quote →