Date Published:May. 10. 2016

Chemical Resistance of Chemical-proof Screws

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Chemical Resistance of Chemical-proof Screws

  • A test piece was used to acquire the test data.
  • Chemical resistance changes with performance conditions.
    Always carry out tests under performance conditions similar to actual conditions in advance.

Teflon*coating's chemical resistance

Chemical name Temperature
(℃)
Teflon*coating
SNSS-TF(Hex Socket Head Cap Screws - Teflon Coating)
SNHS-HTF(Hex Head Screws - Teflon Coating for Head)
SWS-HTF(Seal Washers - Teflon Coating)
10% hydrochloric acid 25
50
75
10% nitric acid 25
70
30% sulfuric acid 25
70
10% sodium hydroxide 25
70
10% ammonium hydroxide 25
70
Acetone
25
50
Carbon tetrachloride
25
50
95% ethyl alcohol 25
50
Ethyl Acetate
25
50
Toluene
25
50
Benzene
78
  • ◎:No erosion confirmed
  • 〇:Slight erosion confirmed

*Teflon is a registered trademark of DuPont.

Chemical resistance of Inconel*, Hastelloy**, and nickel

Chemical name
Temperature
Inconel* Hastelloy** Nickel
Dilute sulfuric acid
Room temperature 
A AA A
Boiling point
D A D
Concentrated sulfuric acid
Room temperature 
C AA C
Boiling point
D D D
Dilute hydrochloric acid
Room temperature 
B AA A
Boiling point
D D D
Concentrated hydrochloric acid
Room temperature 
D AA D
Boiling point
D B D
Dilute nitric acid
Room temperature 
D AA D
Boiling point
AA D
Concentrated nitric acid
Room temperature 
A AA D
Boiling point
D D
Dilute phosphoric acid
Room temperature 
AA AA AA
Boiling point
AA D
Concentrated phosphoric acid
Room temperature 
AA AA AA
Boiling point
B D
Sodium hydroxide (weak)
Room temperature Boiling point
AA AA
Boiling point
C AA
Sodium hydroxide (concentrated)
Room temperature 
AA AA
Boiling point
C AA
  • AA : Highly Excellent
  •  A : Very Good
  •  B : Satisfactory
  •  C : Limit
  •  D : Not satisfactory

Screws of special materials including Inconel*, Hastelloy** and nickel are available.
* Inconel is a registered trademark of Special Metals Corporation.
**Hastelloy is a registered trademark of Haynes.

Titanium's chemical resistance

Chemical name
Composition (%) Corrosion-resistant
Pure Titanium
SUS304
Hydrochloric acid
10 ×
30 × ×
Sulfuric acid
10 -
50 × ×
Nitric acid
10
50
Aqua regia
(HCI:HNO3)
3:1 ×
Chromic acid
5 -
Hydrofluoric acid
5 × ×
Phosphoric acid
50(ventilation)
Ferric chloride
10 - 30 ×
Copper chloride
10 - 30 ×
Sodium chloride
10 - 40
Calcium chloride
50
Ammonium chloride
40 -
Magnesium chloride
40
Ferrous sulfate
10 - 50
Ammonia
10 - 30
Sodium hydroxide
50
Sodium carbonate
10
Hydrogen sulfide
Dry gas
Moist gas
Chlorine
Dry gas
× -
Moist gas
-
Sulfurous acid gas
Dry gas
-
Moist gas
-
Seawater
High flow rate
-
Formic acid
10 - 50
Lactic acid
50
Oxalic acid
20 × -
Citric acid
10 - 50

Test temperature: Normal temperature

  • ◎:<0.127 mm/year
  • 〇:0.127 - 0.508 mm/year
  • △:0.508 - 1.27 mm/year
  • ×:>1.27 mm/year

Titanium screws are available.


 

Ceramic's chemical resistance

Chemical name
Temperature
Time
Effect
35% hydrochloric acid Boiling
30 minutes
70% nitric acid Boiling
30 minutes
98% sulfuric acid Boiling
30 minutes
90% phosphoric acid Boiling
30 minutes
60% hydrofluoric acid 20℃ 24 hours
10% potassium hydroxide 80℃ 7 days
Potassium hydroxide
500℃(boiling) 24 hours
Sodium hydroxide
500℃(boiling) 24 hours
Sodium carbonate
900℃(boiling) 24 hours
Sodium sulfate
1000℃(boiling) 24 hours
Potassium fluoride
90℃(boiling) 4 hours
×
  • ◎:No erosion confirmed
  • 〇:Minor erosion
  • △:Medium erosion
  • ×:Major erosion

Ceramic screws are available.


 

Resin's chemical resistance

Chemical name
PTFE PEEK VESPEL®
SP-1
VESPEL®
SCP-5000
PPS H-PVC RENY PC PP PVDF
10% hydrochloric acid ×
10% sulfuric acid ×
50%sulfuric acid × × × × -
10% nitric acid ×
50% nitric acid × × × × × -
10% hydrofluoric acid - ×
50% hydrofluoric acid × × × × ×
Phosphoric acid
- - ×
Formic acid
×
Acetic acid
×
Citric acid
Chromic acid
- - ×
Boric acid
Methyl alcohol
- -
Glycol
- - - -
Ammonia
× ×
10% sodium hydroxide × -
10% potassium hydroxide × ×
Calcium hydroxide
- - ×
Water
Hydrogen sulfide (gas)
- - -
Sulfur dioxide
- - - -
Ammonium nitrate
- - -
Sodium nitrate
- - - ×
Calcium carbonate
- - - ×
Calcium chloride
- -
Magnesium chloride
- -
Magnesium sulfate
- - -
Zinc sulfate
- - -
Hydrogen peroxide
  • 〇:Available
  • △:Available depending on the conditions
  • ×: Cannot be used

This is test data with a specimen used at room temperature (23°C).
Plastic screws of various chemical-resistant materials are available.



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