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FEP vs SS 316: Chemical Resistance Compared

Of 821 source rows rated for both materials at 20 °C, 741 (90 %) have the same rating. FEP is rated better in 77 rows and SS 316 in 3. A row is one chemical at one concentration.

Summary

FEP is rated better with
Mineral acids (+35 points); Oxidising agents and halogens (+21 points)
Within 10 points of each other
Organic acids; Alkalis; Salts and salt solutions; Alcohols and glycols; Phenols; Ketones and aldehydes; Esters and ethers; Amines and nitrogen compounds; 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

FEP

Fluorinated ethylene propylene

FEP has nearly the chemical resistance of PTFE and can be melt-processed. Its service temperature, about 200 °C, is lower than that of PTFE.

Rated rows: 908. A 99 %, B 0 %, C 1 %, D 0 %

All chemicals for FEP

SS 316

Stainless steel 1.4401 (AISI 316)

Stainless steel 316 (1.4401) contains molybdenum, which improves resistance to chlorides over 304. Hydrochloric acid and other halide acids still cause pitting.

Rated rows: 868. A 89 %, B 4 %, C 2 %, D 4 %

All chemicals for SS 316

Share of rows rated A or B, by chemical class

FEP, SS 316: Share of rows rated A or B, by chemical classMineral acids: FEP 100 %, SS 316 65 %. Organic acids: FEP 100 %, SS 316 98 %. Alkalis: FEP 100 %, SS 316 100 %. Salts and salt solutions: FEP 100 %, SS 316 93 %. Oxidising agents and halogens: FEP 100 %, SS 316 79 %. Alcohols and glycols: FEP 100 %, SS 316 100 %. Phenols: FEP 100 %, SS 316 100 %. Ketones and aldehydes: FEP 100 %, SS 316 100 %. Esters and ethers: FEP 100 %, SS 316 100 %. Amines and nitrogen compounds: FEP 100 %, SS 316 95 %. Aromatic hydrocarbons: FEP 100 %, SS 316 100 %. Fuels, mineral oils and aliphatic hydrocarbons: FEP 100 %, SS 316 100 %. Vegetable and animal oils, fats, essential oils: FEP 100 %, SS 316 100 %. Halogenated hydrocarbons: FEP 90 %, SS 316 88 %. Foods and beverages: FEP 100 %, SS 316 100 %.Mineral acidsMineral acids, FEP: 100 % (55)100 %Mineral acids, SS 316: 65 % (60)65 %Organic acidsOrganic acids, FEP: 100 % (64)100 %Organic acids, SS 316: 98 % (55)98 %AlkalisAlkalis, FEP: 100 % (18)100 %Alkalis, SS 316: 100 % (22)100 %Salts and salt solutionsSalts and salt solutions, FEP: 100 % (197)100 %Salts and salt solutions, SS 316: 93 % (175)93 %Oxidising agents and halogensOxidising agents and halogens, FEP: 100 % (52)100 %Oxidising agents and halogens, SS 316: 79 % (57)79 %Alcohols and glycolsAlcohols and glycols, FEP: 100 % (57)100 %Alcohols and glycols, SS 316: 100 % (58)100 %PhenolsPhenols, FEP: 100 % (14)100 %Phenols, SS 316: 100 % (11)100 %Ketones and aldehydesKetones and aldehydes, FEP: 100 % (33)100 %Ketones and aldehydes, SS 316: 100 % (33)100 %Esters and ethersEsters and ethers, FEP: 100 % (69)100 %Esters and ethers, SS 316: 100 % (69)100 %Amines and nitrogen compoundsAmines and nitrogen compounds, FEP: 100 % (38)100 %Amines and nitrogen compounds, SS 316: 95 % (38)95 %Aromatic hydrocarbonsAromatic hydrocarbons, FEP: 100 % (14)100 %Aromatic hydrocarbons, SS 316: 100 % (14)100 %Fuels, mineral oils and aliphatic hydrocarbonsFuels, mineral oils and aliphatic hydrocarbons, FEP: 100 % (74)100 %Fuels, mineral oils and aliphatic hydrocarbons, SS 316: 100 % (76)100 %Vegetable and animal oils, fats, essential oilsVegetable and animal oils, fats, essential oils, FEP: 100 % (47)100 %Vegetable and animal oils, fats, essential oils, SS 316: 100 % (48)100 %Halogenated hydrocarbonsHalogenated hydrocarbons, FEP: 90 % (49)90 %Halogenated hydrocarbons, SS 316: 88 % (24)88 %Foods and beveragesFoods and beverages, FEP: 100 % (46)100 %Foods and beverages, SS 316: 100 % (46)100 %
FEPSS 316
Rating at 20 °C. Only classes with at least 8 rated rows for both materials are shown.

How often the two ratings agree

FEP, SS 316: How often the two ratings agreeFEP A, SS 316 A: 741; FEP A, SS 316 B: 35; FEP A, SS 316 C: 15; FEP A, SS 316 D: 26; FEP B, SS 316 A: 3; FEP B, SS 316 D: 1.SS 316ABCDFEPAFEP A, SS 316 A: 741741FEP A, SS 316 B: 3535FEP A, SS 316 C: 1515FEP A, SS 316 D: 2626BFEP B, SS 316 A: 33FEP B, SS 316 B: 00FEP B, SS 316 C: 00FEP B, SS 316 D: 11CFEP C, SS 316 A: 00FEP C, SS 316 B: 00FEP C, SS 316 C: 00FEP C, SS 316 D: 00DFEP D, SS 316 A: 00FEP D, SS 316 B: 00FEP D, SS 316 C: 00FEP D, SS 316 D: 00
Number of source rows for each pair of ratings at 20 °C. Outlined cells are rows where both materials have the same rating.

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 classFEP: rated A or BSS 316: rated A or B
Mineral acids100 % (55 rows)65 % (60 rows)
Organic acids100 % (64 rows)98 % (55 rows)
Alkalis100 % (18 rows)100 % (22 rows)
Salts and salt solutions100 % (197 rows)93 % (175 rows)
Oxidising agents and halogens100 % (52 rows)79 % (57 rows)
Alcohols and glycols100 % (57 rows)100 % (58 rows)
Phenols100 % (14 rows)100 % (11 rows)
Ketones and aldehydes100 % (33 rows)100 % (33 rows)
Esters and ethers100 % (69 rows)100 % (69 rows)
Amines and nitrogen compounds100 % (38 rows)95 % (38 rows)
Aromatic hydrocarbons100 % (14 rows)100 % (14 rows)
Fuels, mineral oils and aliphatic hydrocarbons100 % (74 rows)100 % (76 rows)
Vegetable and animal oils, fats, essential oils100 % (47 rows)100 % (48 rows)
Halogenated hydrocarbons90 % (49 rows)88 % (24 rows)
Foods and beverages100 % (46 rows)100 % (46 rows)

Where the ratings differ most

Rows where the two ratings at 20 °C are at least two grades apart: 42 in total, the first 40 shown.

ChemicalConcentrationFEPSS 316
Aniline HydrochloridesaturatedAD
Antimony Trichloride90 %AD
Antimony TrichlorideaqueousAD
BromineAD
Bromine VaporsAD
Chlorine10 % wetAD
Chloroacetic AcidAD
Copper(I) ChlorideaqueousAD
Copper(II) ChloridesaturatedAD
FluorineAD
Hydrobromic Acid40 %AD
Hydrobromic Acid50 %AD
Hydrobromic AciddiluteAD
Hydrochloric Acid1-5 %AD
Hydrochloric Acid20 %AD
Hydrochloric Acid35 %AD
Hydrochloric AcidconcentratedAD
Hydrofluoric Acid50 %AD
Hydrofluoric Acid70 %AD
Ferric Chloride (Iron(III) Chloride)saturatedAD
Mercury(II) ChlorideaqueousAD
Phenylhydrazine HydrochlorideAD
Potassium BisulfateAD
Potassium BisulfateaqueousAD
Sulfuric Acid40 %AD
Sulfuric Acid80 %AD
Aluminum Chloride10 %AC
Aluminum ChloridesaturatedAC
Ammonium PersulfatesaturatedAC
Ammonium PersulfateaqueousAC
Amyl ChlorideAC
Aqua RegiaBD
Hydrofluoric Acid100 %AC
Hydrogen FluorideanhydrousAC
PhosgeneliquidAC
PhosgenegaseousAC
Sodium ChloritediluteAC
Sodium Iodideany concentrationAC
Sulfuric Acid60 %AC
Tin(II) ChloridesaturatedAC

Rating scale

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

HDPE vs FEPHDPE vs SS 316LDPE vs FEPLDPE vs SS 316PP vs FEPPP vs SS 316PVC Rigid vs FEPPVC Rigid vs SS 316PVC Flexible vs FEPPVC Flexible vs SS 316PMP vs FEPPMP vs SS 316Polystyrene vs FEPPolystyrene vs SS 316SAN vs FEPSAN vs SS 316Polycarbonate vs FEPPolycarbonate vs SS 316PETG vs FEPPETG vs SS 316

Frequently Asked Questions

Is FEP or SS 316 more chemical-resistant?

Of 821 chemicals rated for both materials at 20 °C, FEP and SS 316 share the same rating in 741 rows (90 %). FEP is rated better in 77 rows and SS 316 in 3 rows.

How do FEP and SS 316 compare for chemical resistance?

Based on 821 chemicals tested for both: FEP is rated better with Mineral acids, Oxidising agents and halogens. SS 316 is rated better with –. They perform similarly with Organic acids, Alkalis, Salts and salt solutions, Alcohols and glycols.

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.