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.

PFA Coating's chemical resistance

Chemical name Temperature
(℃)		 PFA Coating
SNHS-HTF（Hex Head Screws - PFA Coating for Head）
SWS-HTF（Seal Washers - PFA 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 〇
50 〇
Carbon tetrachloride
 25 〇
50 〇
95％ ethyl alcohol 25 ◎
50 ◎
Ethyl Acetate
 25 〇
50 〇
Toluene
 25 〇
50 〇
Benzene
 78 〇
  • ◎：No erosion confirmed
  • 〇：Slight erosion confirmed

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 〇 ×
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 〇 ×
Sodium chloride
 10 - 40 ◎ 〇
Calcium chloride
 50 ◎ 〇
Ammonium chloride
 40 ◎ -
Magnesium chloride
 40 ◎ 〇
Ferrous sulfate
 10 - 50 ◎ 〇
Ammonia
 10 - 30 ◎ ◎
Sodium hydroxide
 50 ◎ ◎
Sodium carbonate
 10 ◎ ◎
Hydrogen sulfide
 Dry gas
◎ △
Moist gas
 ◎ 〇
Chlorine
 Dry gas
× -
Moist gas
 ◎ -
Sulfurous acid gas
 Dry gas
◎ -
Moist gas
 ◎ -
Seawater
 High flow rate
 ◎ -
Formic acid
 10 - 50 〇 〇
Lactic acid
 50 ◎ 〇
Oxalic acid
 20 × -
Citric acid
 10 - 50 ◎ 〇

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 〇
60% hydrofluoric acid 20℃ 24 hours △
10% potassium hydroxide 80℃ 7 days
 ◎
Potassium hydroxide
 500℃(boiling) 24 hours △
Sodium hydroxide
 500℃(boiling) 24 hours 〇
Sodium carbonate
 900℃(boiling) 24 hours 〇
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 〇 〇 〇 〇 〇 〇 × 〇 〇 〇
10％ sulfuric acid 〇 〇 〇 〇 〇 〇 × 〇 〇 〇
50％sulfuric acid 〇 × × △ × 〇 × △ - 〇
10％ nitric acid 〇 〇 △ △ 〇 〇 × 〇 〇 〇
50％ nitric acid 〇 × × × × △ × △ - 〇
10％ hydrofluoric acid 〇 - △ △ △ △ × 〇 〇 〇
50％ hydrofluoric acid 〇 × × × × △ × △ △ △
Phosphoric acid
 〇 〇 - - △ 〇 × 〇 〇 〇
Formic acid
 〇 △ △ △ 〇 △ × 〇 〇 〇
Acetic acid
 〇 〇 〇 〇 〇 〇 × 〇 〇 〇
Citric acid
 〇 〇 〇 〇 〇 〇 △ 〇 〇 〇
Chromic acid
 〇 〇 - - △ 〇 × 〇 〇 〇
Boric acid
 〇 〇 〇 〇 〇 〇 △ 〇 〇 〇
Methyl alcohol
 〇 〇 △ △ 〇 〇 - △ - 〇
Glycol
 〇 〇 〇 〇 〇 - - 〇 - -
Ammonia
 〇 〇 × △ 〇 〇 〇 × 〇 〇
10％ sodium hydroxide 〇 〇 × △ 〇 〇 〇 - 〇 〇
10％ potassium hydroxide 〇 〇 × △ △ 〇 〇 × 〇 〇
Calcium hydroxide
 〇 〇 - - △ 〇 × 〇 〇 〇
Water
〇 〇 〇 〇 〇 〇 △ 〇 〇 〇
Hydrogen sulfide (gas)
 〇 〇 - - 〇 - 〇 〇 〇 〇
Sulfur dioxide
 〇 〇 - - △ - 〇 〇 〇 -
Ammonium nitrate
 〇 〇 - - 〇 - 〇 〇 〇 〇
Sodium nitrate
 〇 〇 - - 〇 - 〇 × 〇 〇
Calcium carbonate
 〇 〇 - - 〇 - 〇 × 〇 〇
Calcium chloride
 〇 〇 - - 〇 〇 〇 〇 〇 〇
Magnesium chloride
 〇 〇 - - 〇 〇 〇 〇 〇 〇
Magnesium sulfate
 〇 〇 - - 〇 - 〇 〇 〇 〇
Zinc sulfate
 〇 〇 - - 〇 - 〇 〇 〇 〇
Hydrogen peroxide
 〇 〇 △ △ △ 〇 △ 〇 〇 〇
  • 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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