Summary
- SS 304 is rated better with
- Phenols (+100 points); Organic acids (+62 points); Mineral acids (+58 points); Alkalis (+24 points); Oxidising agents and halogens (+23 points); Amines and nitrogen compounds (+21 points); Salts and salt solutions (+17 points); Esters and ethers (+12 points)
- Within 10 points of each other
- Alcohols and glycols; Ketones and aldehydes; Aromatic hydrocarbons; Fuels, mineral oils and aliphatic hydrocarbons; Vegetable and animal oils, fats, essential oils; Halogenated hydrocarbons; Foods and beverages
Points are the difference in the share of rows rated A or B.
The two materials
Acetal (POM)
Polyoxymethylene (acetal)
Acetal (POM) resists many organic solvents and fuels. Strong acids and oxidising agents degrade it.
Rated rows: 956. A 41 %, B 32 %, C 12 %, D 15 %
SS 304
Stainless steel 1.4301 (AISI 304)
Stainless steel 304 (1.4301) resists oxidising acids and most organic chemicals. Chlorides cause pitting and stress-corrosion cracking.
Rated rows: 865. A 88 %, B 5 %, C 2 %, D 5 %
Share of rows rated A or B, by chemical class
How often the two ratings agree
Chemical classes were assigned by this site, not by the source. Mixtures and trade products without a clear class are not counted.
By chemical class
| Chemical class | Acetal (POM): rated A or B | SS 304: rated A or B |
|---|---|---|
| Mineral acids | 5 % (63 rows) | 63 % (60 rows) |
| Organic acids | 34 % (64 rows) | 96 % (53 rows) |
| Alkalis | 76 % (21 rows) | 100 % (22 rows) |
| Salts and salt solutions | 76 % (197 rows) | 93 % (175 rows) |
| Oxidising agents and halogens | 43 % (63 rows) | 66 % (56 rows) |
| Alcohols and glycols | 96 % (57 rows) | 100 % (58 rows) |
| Phenols | 0 % (14 rows) | 100 % (11 rows) |
| Ketones and aldehydes | 91 % (35 rows) | 100 % (33 rows) |
| Esters and ethers | 88 % (68 rows) | 100 % (69 rows) |
| Amines and nitrogen compounds | 74 % (38 rows) | 95 % (38 rows) |
| Aromatic hydrocarbons | 100 % (14 rows) | 100 % (14 rows) |
| Fuels, mineral oils and aliphatic hydrocarbons | 96 % (73 rows) | 100 % (76 rows) |
| Vegetable and animal oils, fats, essential oils | 100 % (45 rows) | 100 % (48 rows) |
| Halogenated hydrocarbons | 80 % (70 rows) | 88 % (24 rows) |
| Foods and beverages | 100 % (46 rows) | 100 % (46 rows) |
Where the ratings differ most
Rows where the two ratings at 20 °C are at least two grades apart: 177 in total, the first 40 shown.
| Chemical | Concentration | Acetal (POM) | SS 304 |
|---|---|---|---|
| Acetic Acid | 100 % | D | A |
| Acetic Acid | 90 % | D | A |
| Acetyl Chloride | 100 % | D | A |
| Ammonium Bifluoride | 50 % | D | A |
| Arsenic Acid | D | A | |
| Arsenic Acid | aqueous | D | A |
| Arsenic Pentoxide | D | A | |
| Bisulfite Liquor | D | A | |
| Bisulfite Liquor with SO2 | saturated | D | A |
| Butylphenol | 100 % | D | A |
| Butyric Acid | D | A | |
| Calcium Bisulfite | saturated | D | A |
| Calcium Bisulfite | aqueous | D | A |
| Chlorine | 97 % | D | A |
| Chlorine Gas | D | A | |
| Chloroform | 100 % | D | A |
| Chromic Acid | 10 % | D | A |
| Cresol | D | A | |
| Dichloroethylene | technical grade | D | A |
| Formic Acid | 50 % | D | A |
| Formic Acid | 98-100 % | D | A |
| Gear Oil, EP (Hypoid), 110°C | D | A | |
| Hydrocyanic Acid (Hydrogen Cyanide) | technical grade | D | A |
| Hydrocyanic Acid (Hydrogen Cyanide) | aqueous | D | A |
| Hydrogen Peroxide | 100 % | D | A |
| Hydrogen Peroxide | 30 % | D | A |
| Hydrogen Peroxide | 90 % | D | A |
| Nitric Acid | 1-10 % | D | A |
| Nitric Acid | 50 % | D | A |
| Nitric Acid | 66 % | D | A |
| Nitric Acid | 70 % | D | A |
| Nitrogen Tetroxide | D | A | |
| Nitrous Exhaust Gases | low concentration | D | A |
| Nitrous Gases | dilute | D | A |
| Oleum (Fuming Sulfuric Acid) | 10 % SO3 | D | A |
| Oleum Vapors | low concentration | D | A |
| p-tert-Butylphenol | technical grade | D | A |
| Phenol | 10 % | D | A |
| Phenol | 100 % | D | A |
| Phosphoric Acid | 20 % | D | A |
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.
More comparisons
Frequently Asked Questions
Is Acetal (POM) or SS 304 more chemical-resistant?
Of 845 chemicals rated for both materials at 20 °C, Acetal (POM) and SS 304 share the same rating in 377 rows (45 %). Acetal (POM) is rated better in 27 rows and SS 304 in 441 rows.
How do Acetal (POM) and SS 304 compare for chemical resistance?
Based on 845 chemicals tested for both: Acetal (POM) is rated better with –. SS 304 is rated better with Phenols, Organic acids, Mineral acids, Alkalis. They perform similarly with Alcohols and glycols, Ketones and aldehydes, Aromatic hydrocarbons, Fuels, mineral oils and aliphatic hydrocarbons.
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.