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ISO 14644-1

Cleanroom Furniture in Stainless Steel - Why 1.4301 or 1.4404?

Stainless steel is the default material for cleanrooms because it is low-particle, corrosion-resistant and withstands disinfection. This guide explains the difference between 1.4301 and 1.4404, what matters for surface finish, crevice-free design and castors, and how to match furniture to your ISO cleanroom class.

5 minStand: 2026-07Geprüft: Technical editors
View cleanroom furniture
1.4404
acid-resistant 316L
Ra < 0.8 µm
recommended roughness
ISO 14644-1
cleanroom classes
crevice-free
welded construction
Inhalt
  1. Material choice
  2. Surface and Ra
  3. Crevice-free design
  4. Castors and mobility
  5. Frequently asked questions

1.4301 or 1.4404 - which stainless steel fits?

Cleanroom furniture almost always uses austenitic chromium-nickel steels. 1.4301 (AISI 304) is the standard grade for dry areas, while 1.4404 (AISI 316L) adds molybdenum and resists chlorides and aggressive disinfectants far better.

For electronics and general assembly, 1.4301 usually suffices. In pharma, biotech and semiconductor areas with frequent wipe disinfection or ultra-pure water, 1.4404 is required, because molybdenum prevents pitting corrosion and stabilises the passive layer.

The L in 316L means low carbon: the reduced carbon content prevents chromium-carbide formation at weld seams and thus intergranular corrosion - important for welded furniture.

Why does surface finish matter so much?

The smoother the surface, the fewer particles and microbes adhere and the easier it is to clean. The key figure is the mean roughness Ra in micrometres. A guideline for cleanroom furniture is Ra < 0.8 µm; GMP areas often specify electropolished surfaces with Ra < 0.5 µm.

  • Ground (grit 240): standard for 304 work surfaces, Ra about 0.4 to 0.8 µm.
  • Electropolished: removes micro-peaks, smooths the passive layer, Ra < 0.4 µm.
  • Avoid matt-brushed finishes: open grooves trap particles and hinder disinfection.
  • Edges deburred and radiused, no sharp corners acting as particle traps.
Electropolishing does more than improve looks: it enriches chromium at the surface and measurably raises corrosion resistance - ideal for the highest cleanroom class.
Cleanroom workstation

How to plan the complete low-particle workstation.

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What does crevice-free construction mean?

Every gap, screw and dead corner is a reservoir for particles and microorganisms that cannot be wiped clean. Cleanroom furniture is therefore built as closed and smooth as possible, with continuously ground-flush weld seams.

  • Fully closed, welded frames instead of bolted profiles.
  • Ground-flush, crevice-free weld seams instead of silicone joints.
  • Open frames without horizontal ledges so dust cannot settle.
  • Height-adjustable feet or castors without open cavities.
Perforated or grid shelves are often better than solid ones in a cleanroom: the laminar downflow (LAF) from above can carry particles downward unobstructed.

Which castors belong in a cleanroom?

Standard castors with plastic housings and open bearings generate abrasion and shed particles. Cleanroom castors are made of stainless steel with sealed bearings, quiet polyurethane treads and no open threads or grease nipples.

  • Stainless steel fork 1.4301/1.4404, no painted or galvanised parts.
  • Sealed, maintenance-free bearings with no grease escape.
  • Low-abrasion PU or elastomer tread, non-marking and quiet.
  • Conductive (ESD) castors when handling electronic components.
  • Brakes with a smooth, cleanable surface instead of open mechanics.
In ESD-relevant cleanrooms, castors and furniture should be dissipative (resistance typically 10⁶ to 10⁹ Ω) so static charge drains in a controlled way and particles are not attracted electrostatically.
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How to combine ESD protection with low-particle design.

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Frequently asked questions

When is 1.4301 enough and when do I need 1.4404?

1.4301 (304) is fine in dry, neutral areas such as electronics assembly. As soon as chloride-bearing or aggressive disinfectants are used frequently, for example in pharma and biotech, 1.4404 (316L) with molybdenum is the right choice.

What surface roughness should cleanroom furniture have?

A guideline is Ra below 0.8 µm. GMP and high-end cleanrooms recommend electropolished surfaces with Ra below 0.5 µm, because smoother surfaces bind fewer particles and are easier to disinfect.

Why is furniture welded rather than bolted?

Bolted joints create crevices where particles and microbes collect and that cannot be wiped clean. Fully welded, ground-flush constructions are crevice-free and therefore cleanroom-compatible.

Are ordinary furniture castors allowed in a cleanroom?

No. Standard castors shed particles through abrasion and open bearings. Cleanrooms use stainless steel castors with sealed bearings and low-abrasion PU treads, dissipative if needed.

Looking for stainless cleanroom furniture?

We supply tables, trolleys, cabinets and seating in 1.4301 and 1.4404 - crevice-free welded, electropolished and with cleanroom-grade castors.

304 and 316L

Stainless steel 1.4301 and 1.4404 for every cleanroom class.

Smooth surfaces

Ground or electropolished, Ra below 0.8 µm.

Crevice-free build

Welded, cleanable construction with no particle traps.

Expert advice

Our specialists help with grade and equipment.

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