ASTM A449 Specifications
Technical Menu Posted on July 1st, 2015 by vaproThis ASTM A449 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 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| TYPE 2 | **Withdrawn in 2003** |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 |
Related: ASTM A449 Specifications on ASTM.org
