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ASTM A449 Bolts

This ASTM A449 Bolts specification covers quenched and tempered, medium strength hex cap screws, headed bolts, rods and nuts from 1/4” to 3” in diameter. ASTM A449 products are manufactured from medium carbon or alloy steel and are heat treated to acheive their required mechanical properties. ASTM A449 is very similar to ASTM A325 in chemistry and strength but covers a wider range of diameters.

Specifications

A449 Fasteners are designated by type denoting chemical composition as follows:

Type 1:
- Plain Carbon Steel, Carbon Boron Steel, Alloy Steel, Alloy Boron Steel
Type 2:
- **Withdrawn in 2003**
Type 3:
- Weathering Steel

Chemical Requirements

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)	0.04%	0.04%	0.04%	0.04%
Sulfur (max)	0.05%	0.05%	0.04%	0.04%
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%

Element	Range 1	Range 2	Range 3	Range 4	Range 5	Range 6
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	0.04%	0.04%
Sulfur (max)	0.04%	0.04%	0.04%	0.04%	0.04%	0.04%
Silicon	0.15 – 0.35%	0.30 – 0.50%	0.15 – 0.35%	0.25 – 0.50%	0.15 – 0.35%	0.15 – 0.35%
Copper	0.25 – 0.45%	0.20 – 0.40%	0.20 – 0.50%	0.30 – 0.50%	0.30 – 0.60%	0.20 – 0.40%
Nickel	0.25 – 0.45%	0.50 – 0.80%	0.25 – 0.50%	0.50 – 0.80%	0.30 – 0.60%	0.20 – 0.40%
Chromium	0.45 – 0.65%	0.50 – 0.75%	0.30 – 0.50%	0.50 – 1.00%	0.60 – 0.90%	0.45 – 0.65%
Vanadium			0.020% min
Molybdenum		0.06% max		0.10% max
Titanium				0.05% max

Mechanical Requirements

Size	Tensile, ksi	Yield, ksi	Elong. %, min	RA %, min
1/4” – 1”	120 min	92 min	14	35
1-1/8” – 1-1/2”	105 min	81 min	14	35
1-5/8” – 3”	90 min	58 min	14	35

See Also: ASTM A449 Specifications on ASTM.org.