BOLTS MATERIAL

ASTM defined the material grades for stud bolts. The most common grades are ASTM A193 for thread rods and ASTM A194 for the nuts:

  • ASTM A193 covers alloy and stainless steel bolting material for pressure vessels, valves, flanges, and fittings for high temperature or high pressure service, or other special purpose applications.
     
  • ASTM A194 covers a variety of carbon, alloy, and martensitic and austenitic stainless steel nuts. These nuts are intended for high-pressure or high-temperature service, or both.

 

 Stud bolts materials.pdf

 

DESIGN
TEMPERATURE
GRADE FLANGES GRADE BOLT GRADE NUTS
-195° to 102°C ASTM A 182 Gr. F304, F304L, F316, F316L, F321, F347 A320 Gr. B8 Class 2 A194 Gr. 8A
-101° to -47°C ASTM A 350 Gr. LF3 A 320 Gr. L7 A 194 Gr. 7
-46° to -30°C ASTM A 350 Gr. LF2 A 320 Gr. L7 A 194 Gr. 7
-29° to 427°C ASTM A 105 A 193 Gr. B7 A 194 Gr. 2H
428° to 537°C ASTM A 182 Gr. F11, F22 A 193 Gr. B16 A 194 Gr. 2H
538° to 648°C ASTM A182 Gr. F11, F22 A 193 Gr. B8 Class 1 A 194 Gr. 8A
649° to 815°C ASTM A182 Gr. F304 H, F316 H A 193 Gr. B8 Class 1 A 194 Gr. 8A

 

 

MECHANICAL PROPERTIES OF STUD BOLTS

Stud bolts mechanical requirements

(Source Trouvay & Cauvin - Piping equipment "Blue book")

 

TYPICAL COATINGS FOR STUD BOLTS

  • Special coatings: PTFE (Teflon), UBE look electrofilm, Molykote, Delta Shield)
  • Chemical bath: Phospathing, hot dip galvanizing, Daromet, Deltatone, Nicke electroless
  • Electroplating: Zinc, copper, nickel, silver
  • Flouro carbon: Xylan and Xylar

 

 

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