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.

A449 Bolts

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

TYPE DESCRIPTION
TYPE 1 Plain Carbon Steel, Carbon Boron Steel, Alloy Steel, Alloy Boron Steel
TYPE 2 **Withdrawn in 2003**
TYPE 3 Weathering Steel

 

A449 CHEMICAL PROPERTIES

Type 1 Bolts
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%
Type 3 Bolts
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
 

A449 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.