ASTM F1544 Grade 55 is a standard material specification for straight, bent, headed, headless anchor bolts and all-thread anchor rods, made of low yield carbon steel. ASTM F1554 Grade 55 anchors bolts are designated with minimum yield strength value of 55 ksi or 380 MPa. These Grade 55 anchors bolts or anchor rods are intended for anchoring structural supports to concrete foundations. Such structural supports include building columns, column supports for highway signs, street lighting and traffic signals, steel bearing plates, and similar applications.
Supplementary requirements are included to provide for grade 55 weldable steel, permanent manufacturers and grade identification marking, and impact properties for grade 55.
Grade Classification
Type |
Descriptions |
Tensile Strength, ksi (MPa) |
Yield Strength, min, ksi (MPa) |
Diameter, Range, Inch. |
Grade 55 |
High strength, low alloy, 55 ksi yield steel anchor bolts |
75 - 95 (517 - 665) |
55 (380) |
1/2 - 4 |
(For other grades, please visit ASTM F1554)
Chemical Composition
Element |
Composition, % |
Grades 55 |
All Diameters |
Carbon, max |
Heat |
- |
Product |
- |
Manganese |
Heat |
- |
Product |
- |
Phosphorus, max |
Heat |
0.04 |
Product |
0.048 |
Sulfur, max |
Heat |
0.05 |
Product |
0.058 |
Copper, min (when specified) |
Heat |
0.20 |
Product |
0.18 |
Mechanical Properties
[Bar & Machined Specimen]
Property |
Grade 55 |
Tensile Strength, ksi |
75 - 95 |
Yield Strength, min, ksi (0.2% Offset) |
55 |
Elongation in 8 inch, min, % [Note A] |
18 |
Elongation in 2 inch, min, % [Note A] |
21 |
Reduction of Area, min, % |
30 |
Note A:Elongation in 8 Inch applies to bars. Elongation in 2 inch applies to machined specimens.
Protective Coatings
- Zinc, Hot Dip or Mechanically Deposited:
- When zinc-coated anchor bolts are required, the purchaser
shall specify the coating process, for example, hot dip,
mechanically deposited, or no preference. When no preference
is specified, the supplier may furnish bolts coated with either
process. The supplier’s option is limited to one process per
item, with no mixed processes in a lot.
- When hot-dip zinc coated anchor bolts are specified,
the anchor bolts and nuts shall be zinc-coated in accordance
with the requirements of Specification F2329/F2329M.
- When mechanically deposited zinc coated anchor
bolts are provided, the anchor bolts and nuts shall be zinccoated
in accordance with the requirements of Specification
B695, Class 55.
- Unless otherwise specified, when zinc-coated washers
are required, the washers shall be hot-dip zinc-coated in
accordance with Specification F2329/F2329M, or mechanically
deposited zinc coated in accordance with Specification
B695, Class 55. The coating process for the washers need not
be the same as that for the anchor bolts and nuts.
- Other Coatings:
- When indicated on the inquiry and purchase order,
coatings other than those in 7.1 shall be as agreed upon by the
purchaser and supplier.
Recommended Nuts & Washers
Anchor Bolts |
Recommended A563 Nuts |
Plain Finish |
Hot-Dip or Mechanical Zinc Coated |
Bolt Grade |
Diameter, Inch |
Grade |
Style |
Grade |
Style |
Grade 55 |
1/2 - 1 1/2 |
A |
Hex |
A |
Heavy Hex |
Over 1-1/2 - 4 |
A |
Heavy Hex |
A |
Heavy Hex |
Reference Standards
-
ASTM A194
Specification for Carbon, Alloy, and Stainless Steel Nuts for High Pressure or High Temperature Service, or Both
-
ASTM A194M
Specification for Carbon, Alloy, and Stainless Steel Nuts for High Pressure or High Temperature Service, or Both
-
ASTM A563
Specification for Carbon and Alloy Steel Nuts
-
ASTM B695
Specification for Coatings of Zinc Mechanically Deposited on Iron and Steel
-
ASTM F436
Specification for Hardened Steel Washers (Metric)
-
ASTM F2329
Specification for Zinc Coating, Hot-Dip for Carbon and Alloy Steel Bolts, Screws, Washers, Nuts,and Special Threaded Fasteners
-
ASTM F2329M
Specification for Zinc Coating, Hot-Dip for Carbon and Alloy Steel Bolts, Screws, Washers, Nuts,and Special Threaded Fasteners
-
ASME B18.2.1
Square, Hex, Heavy Hex, and Askew Head Bolts and Hex, Heavy Hex, Hex Flange, Lobed Head, and Lag Screws (Inch Series)
-
ASME B18.2.2
Square and Hex Nuts
-
ASME B1.1
Unified Inch Screw Threads (UN and UNR Thread Form)