Materials
316L Stainless vs C-22 Hastelloy vs Acrylic: Choosing a Column Material
The body material of a process column shapes its chemical compatibility, pressure capability, cleanability, visibility, and cost. Here's how 316L stainless steel, C-22 Hastelloy, and acrylic compare, and how to pick the right one.
6 min read · Updated June 12, 2026
The short version
Most GMP process columns are built in 316L stainless steel. You move to C-22 Hastelloy when the chemistry is aggressive enough to attack stainless, and to acrylic when seeing the bed matters more than pressure or harsh-chemical resistance.
Side-by-side comparison
| Factor | 316L stainless | C-22 Hastelloy | Acrylic |
|---|---|---|---|
| Chemical resistance | Excellent for most buffers and CIP | Best — handles high chloride, low pH, aggressive CIP | Limited — sensitive to solvents and some chemicals |
| Pressure capability | High | High | Lower (visual / pilot pressures) |
| Visibility | Opaque | Opaque | Transparent — watch the bed directly |
| Cleanliness / GMP | Electropolished, GMP-ready | Electropolished, GMP-ready | Good, but softer surface |
| Relative cost | Moderate | Premium | Lowest |
| Typical use | Most pilot-to-production GMP columns | Corrosive or chloride-heavy processes | Pilot, teaching, and visibility-critical work |
316L stainless steel — the workhorse
316L is the default for a reason: it holds pressure, electropolishes to a clean, low-hold-up surface, stands up to standard buffers and clean-in-place chemistries, and is cost-effective at scale. For the large majority of pilot-to-production GMP separations, it’s the right call.
C-22 Hastelloy — for aggressive chemistries
When a process involves high chloride concentrations, low pH, or especially harsh cleaning regimes, stainless can be at risk of pitting or corrosion over time. C-22 Hastelloy offers markedly better corrosion resistance in those conditions. It carries a premium, so it’s chosen deliberately where the chemistry demands it rather than by default.
Acrylic — when you need to see the bed
Transparent acrylic lets operators watch the packed bed directly, which is valuable for pilot work, method development, training, and any process where visual confirmation of the bed matters. The trade-offs are lower pressure capability and narrower chemical compatibility, so it suits visibility-critical and lower-pressure applications.
How to choose
- Standard GMP process? Start with 316L stainless.
- Chloride-heavy, low-pH, or harsh CIP? Specify C-22 Hastelloy.
- Need to see the bed, lower pressures? Consider acrylic.
Once material is settled, the rest is geometry — see how to size an industrial chromatography column. Mann Welding builds in all three materials, ASME-coded and made in the USA, so the choice can be driven by your process rather than a catalog.
Talk to an engineer about your column
Tell us your process and constraints and we’ll help you spec the right column.