ASTM A453 Grade 660 Class C

High Temperature Stainless Steel Bolting Material

ASTM A453 Grade 660 Class C Fasteners

ASTM A453 Grade 660 Chemical Composition

Elements Content, % Allowable Variation, Over or Under, %
Carbon 0.08 max 0.01 over
Manganese 2.00 max 0.04
Phosphorus 0.04 max 0.005 over
Sulfur 0.03 max 0.005 over
Silicon 1.00 max 0.05
Nickel 24.00 – 27.00 0.20
Chromium 13.50 – 16.00 0.20
Molybdenum 1.00 – 1.50 0.05
Titanium 1.90 – 2.35 0.05
Aluminum 0.35 max 0.05 over
Vanadium 0.10 – 0.50 0.03
Boron 0.001 – 0.010 0.0004 under to 0.001 over

ASTM A453 Grade 660 Class C Mechanical Properties

Tensile Class Tensile Strength, min Yield Strength,(0.2% offset), min Elongation in 4D, min, % Reduction of Area, min, %
ksi Mpa ksi Mpa
C 130 895 85 585 15 18

ASTM A453 Grade 660 Class C Hardness

Brinell Hardness Number Approximate Rockwell Hardness
min max
248 - 341 24 HRC 27 HRC

ASTM A453 Grade 660 Class C Stress Rupture Requirements

Tensile Class Test Temperature ºF [ºC] Stress, min Time to Rupture, min, h [Note] Elongation, min, %
ksi Mpa
C 1200 [650] 56 385 100 5

Note : The combination bar specimen shall be tested continuously at the temperature and at the minimum stress specified or at a greater stress and shall rupture in a time not less than that specified.