AISI 304 Stainless Steel Wire

AISI 304 Stainless Steel Wire is the general-purpose stainless fill, supplied straight, crimped or twisted for wheel, cup, end, roller and bore brushes. It resists ordinary corrosion and will not transfer carbon steel onto the workpiece.

AISI 304 stainless steel wire is a chromium-nickel austenitic brush filament for general wet cleaning, food equipment, metal finishing, tube cleaning, and corrosion-resistant brush constructions where chloride exposure is limited.

Where a project stalls on material choice, the comparison is normally against AISI 316 Stainless Steel Wire, Carbon Steel Wire and Brass Wire, and it turns on working temperature.

Use AISI 316 stainless steel wire for chloride, marine, dairy, beverage, chemical washdown, or higher pitting-resistance requirements. Use carbon steel for dry aggressive cutting and brass or abrasive nylon for lower marking risk.

AISI 304 Stainless Steel Wire is rockwell B 70–95 is typical for annealed to cold-worked brush-wire conditions; final stiffness is geometry-dependent, and AISI 304 wire produces firm tip contact. Finer wire, longer trim, and crimped form improve conformity; coarser wire, shorter trim, higher density, and higher motion increase cutting action and surface risk.

The published filament ranges, set against the grades it competes with. These are filament figures, not finished-brush values.

The part people get wrong: the number that decides scrubbing pressure is diameter over trim length, not the grade name. Two brushes in this material can behave nothing alike.

AISI 304 wire absorbs no water at all; its wet-service question is whether the passive layer holds in the actual chemistry.

Zero water absorption; corrosion resistance depends on chloride level, crevices, contamination, passivation, and the holder alloy.

What this means for your application: dry and wet contact pressure are identical, because nothing swells. What varies with the fluid is corrosion, and 304 is the grade that starts to struggle once chlorides are involved.

A practical check: expose a sample to the real solution at the real temperature for a shift and look for pitting or tea-staining, not for movement in the trim.

AISI 304 alloy data show capability at elevated temperature, but that is not a finished-brush service rating. For a brush, wire temper, anchoring, adhesive, hub, atmosphere, speed, and contact load set the usable temperature.

Design to that answer rather than to a raw-material datasheet figure: a brush rating already accounts for wire working under load rather than bare wire held at temperature with nothing pushing on it.

Where it stops working: validate with a sample if the process sits near the top of that band. A permanent bend under load means the answer is a higher-temperature filament family, not a heavier trim.

The usable limit also moves with diameter, trim and contact pressure. A fine filament under light load tolerates more than a thick one under heavy scrubbing.

Good general corrosion resistance. More susceptible than AISI 316 to chloride pitting and crevice corrosion; not the preferred grade for marine salt, brine, hypochlorite, or persistent chloride washdown.

The same cleaner can be harmless or destructive depending on how strong it is, how hot it runs and how long it sits. Quote the concentration and the dwell time, not just the product name.

Before you commit to a quantity: Specify AISI 304 / UNS S30400 / EN 1.4301 / JIS SUS304, wire diameter, straight or crimped form, temper, passivation condition, operating temperature, chemical exposure, mounting material, and required material certificate.

About 0.03 mm. Below that the filament turns fragile and breaks under ordinary contact pressure, so 0.03–1.00 mm is the working range.

Free trim runs 3–200 mm, and the two interact: a finer filament needs a shorter trim to keep useful stiffness, while a thicker one carries a longer trim and still lands pressure on the tip.

Split the range by duty: roughly 0.03–0.27 mm for light wiping, dusting and surfaces that mark easily, and 0.27–1.00 mm where residue is packed on and point pressure matters more than surface risk.

Tip treatments available on this filament: straight or crimped wire, pickled and passivated, electropolished and degreased.

In practical brush terms: reaching deep into a bore or crevice is a diameter problem before it is a length problem. A thicker filament on a moderate trim pushes further in before the tips fold over.

General wet industrial cleaning, food-equipment cleaning with controlled chemistry, weld and scale removal, tube cleaning, and corrosion-resistant strip or wheel brushes.

The cleaning work it is specified for most often:

• Heat Exchanger Tube Cleaning
• Pipe Robot Brush Attachment Use
• Hose Cleaning
• Tube & Pipe Cleaning
• Steel Rust Removal
• CPAP Hose Cleaning

Brush types built with this fill:

• Custom Tube & Pipe Bore Brushes
• Custom Handheld Detail Brushes
• Custom Cup Brushes
• Custom Spring Brushes

The trade-off: Avoid using AISI 304 as the default in marine, brine, hypochlorite, and persistent chloride environments; use AISI 316 when higher pitting and crevice-corrosion resistance is required.

A usable specification carries the construction, the filament diameter and free trim, the density and contact setting, and the service conditions: wet or dry, temperature, and what the cleaner actually is.

The mistakes that most often send a sample back:

• Selecting Stainless Steel Wire from the material name alone without setting filament diameter, trim length, and density
• Using dry stiffness to predict wet behavior without checking moisture absorption or liquid exposure
• Ignoring trapped abrasive particles, chemical concentration, temperature, or contact motion when assessing surface risk

Reference standards behind the figures on this page: ISO 6892-1; ASTM E8/E8M; ASTM B117; ASTM A580/A580M.

Source: Alleima — Sanmac 304/304L Material Datasheet. Alleima supports the alloy corrosion and elevated-temperature behavior. Do not convert alloy gas-corrosion limits directly into a universal brush assembly limit.