Rating
| Concentration | 20 °C | 50 °C | Remark |
|---|---|---|---|
| 1-5 % | A | A | |
| 20 % | A | B | |
| 30 % | A | B | |
| 85 % | A | C |
Material comparison at 20 °C
Resistance overview
SS 316 shows excellent resistance to Phosphoric Acid across all 4 tested concentrations (1-5 %, 20 %, 30 %, 85 %) at 20 °C, making it a reliable choice for storage, transfer, and handling applications involving this chemical at any of the tested strengths. However, at 50 °C the resistance rating drops, indicating that temperature must be factored into the design. For heated applications, additional testing under actual service conditions is strongly recommended.
Application context
Phosphoric Acid is commonly encountered in metal finishing and laboratory work. SS 316 (Stainless steel 1.4401 (AISI 316)) is a metal typically used for vessels, heat exchangers, fittings and structural components. Because Phosphoric Acid is classified as corrosive, the choice of containment material is especially critical to prevent leaks, equipment damage, and safety hazards.
Practical recommendation
SS 316 can be used with confidence for Phosphoric Acid containment and handling. The A rating indicates that the material shows no significant change in weight, dimensions, or mechanical properties after prolonged contact under test conditions. At elevated temperatures (50 °C), some reduction in resistance occurs, so periodic inspection is advisable for heated applications. Always verify performance under actual operating conditions before committing to a design.
Did you know?
The ratings shown here apply to pure Phosphoric Acid in contact with the base metal. In real-world applications, additives, pigments, and fillers in the material can shift resistance in either direction.
Materials rated A or B at 20 °C
Based on the row for 85 %, 20 °C.
- Thermoplastics
- HDPE A, PP A, PVC Rigid A, LDPE A, Polycarbonate A, PVC Flexible A, Polystyrene A, Polysulfone A, PMP A, SAN A
- Fluoropolymers
- PTFE A, PVDF A, FEP A, ECTFE/ETFE A
- Elastomers
- Viton (FPM) A
- Metals
- SS 304 B
About SS 316
Stainless steel 316 (1.4401) contains molybdenum, which improves resistance to chlorides over 304. Hydrochloric acid and other halide acids still cause pitting.
Rating scale
- A very good resistance
- B good resistance
- C limited resistance
- D not resistant
- – no data
- K no general statement possible
A rating marked * is an estimate in the source, not a test result. An estimate is given as one value without a temperature.
About this data
The ratings come from the chemical resistance list published by Bürkle GmbH, which compiled them from raw-material manufacturers’ data. They describe laboratory tests on the raw material at 20 °C and 50 °C.
A finished part also sees pressure, mechanical stress, welds and mixtures that a laboratory test does not. Treat the rating as a first filter and test under your own conditions before relying on it.