NBK logo

Date Published:May. 10. 2016 Date Updated:Oct. 07. 2024

Chemical Resistance of Chemical-proof Screws

PDF
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＊1, Hastelloy＊2, and nickel

Chemical name
 Temperature
 Inconel＊1 Hastelloy＊2 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＊1, Hastelloy＊2 and nickel are available.


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®＊3
SP-1		 VESPEL®＊3
SCP-5000		 PPS H-PVC RENYTM＊4 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.


＊1： Inconel is a registered trademark of Special Metals Corporation.
＊2： Hastelloy is a registered trademark of Haynes International, Inc.
＊3： VESPEL is a registered trademark of DuPont.
＊4： RENYTM is a trademark or registered trademark of Mitsubishi Gas Chemical Company, Inc.



Engineering Tips HINTS for NEW IDEAS

Examples to help you resolve any issues you may have.

Technical Data Others Machine Tools Semiconductor Manufacturing Equipment Food Machinery Automotive Manufacturing Process Medical Equipment FA Devices Technical Data Special Screws