ASTM A449

ASTM A449 covers headed bolts, rods, and anchor bolts with diameters ranging from 1/4" to 3" inclusive. These medium-strength bolts are manufactured from medium carbon or alloy steel and achieve their mechanical properties through a heat treatment process. They are widely used in general engineering and construction applications.

ASTM A449 bolts are chemically and mechanically similar to ASTM A325 and SAE J429 Grade 5. However, ASTM A449 offers greater flexibility, as it covers a broader diameter range and is not limited to a specific configuration. This makes it a preferred choice for projects requiring versatility and reliable performance.

A449 Types

Type 1	Plain carbon steel, carbon boron steel, alloy steel, or alloy boron steel.
Type 2	Withdrawn (2003)
Type 3	Weathering steel, offering improved resistance to atmospheric corrosion.

A449 Chemical Properties

ASTM A449 – Type 1 Chemical Composition
Element	Carbon Steel	Carbon-Boron Steel	Alloy Steel	Alloy-Boron Steel
Carbon	0.30 – 0.52%	0.30 – 0.52%	0.30 – 0.52%	0.30 – 0.52%
Manganese (min)	0.60%	0.60%	0.60%	0.60%
Phosphorus (max)	0.040%	0.040%	0.035%	0.035%
Sulfur (max)	0.050%	0.050%	0.040%	0.040%
Silicon	0.15 – 0.30%	0.10 – 0.30%	0.15 – 0.35%	0.15 – 0.35%
Boron	—	0.0005 – 0.003%	—	0.0005 – 0.003%
Alloying Elements	—	—	*	*

Type 3 Bolts — Class *
Element	Class A	Class B	Class C	Class D	Class E	Class F
Carbon	0.33 – 0.40%	0.38 – 0.48%	0.15 – 0.25%	0.15 – 0.25%	0.20 – 0.25%	0.20 – 0.25%
Manganese	0.90 – 1.20%	0.70 – 0.90%	0.80 – 1.35%	0.40 – 1.20%	0.60 – 1.00%	0.90 – 1.20%
Phosphorus	0.035% max	0.06 – 0.12%	0.035% max	0.035% max	0.035%	0.035%
Sulfur	0.040% max	0.040% max	0.040% max	0.040% max	0.040% max	0.040% max
Silicon	0.15-0.35%	0.30-0.50%	0.15-0.35%	0.25-0.50%
Copper	0.25-0.45%	0.20-0.40%	0.20-0.50%	0.30-0.50%
Nickel	0.25-0.45%	0.50-0.80%	0.25-0.50%	0.50-0.80%
Chromium	0.45-0.65%	0.50-0.75%	0.30-0.50%	0.50-1.00%
Vanadium			0.020% min
Molybdenum		0.06% max		0.10% max
Titanium				0.05% max