ASTM F3125
Note: In 2016, specifications A325 and A490 were officially withdrawn by ASTM and replaced by ASTM F3125. A325 and A490 heavy hex structural bolts are now grades under the new F3125 specification. A summary of the now obsolete
A325 specification remains on our site for reference purposes only.
This specification covers the chemical, physical and mechanical requirements for structural bolts manufactured from steel and alloy steel, in two strength grades, two styles and two types. This specification is a consolidation of and replacement for six ASTM standards: A325, A325M, A490, A490M, F1852 and F2280. The main difference between this standard and the older, existing standards is that A325s from 1-1/8″ to 1-1/2″ now have the same mechanical requirements as A325s 1″ and under. Previously the larger bolts had slightly lower requirements.
F3125 Bolt Types
| Grade |
Min Strength, Tensile |
Type |
Style |
| A325 |
120ksi min |
1 or 3 |
Heavy Hex Head |
| A325M |
830MPa min |
1 or 3 |
Heavy Hex Head |
| F1852 |
120ksi min |
1 or 3 |
Twist-Off/TC |
| A490 |
150-173ksi |
1 or 3 |
Heavy Hex Head |
| A490M |
1040MPa |
1 or 3 |
Heavy Hex Head |
| F2280 |
150ksi |
1 or 3 |
Twist-Off/TC |
- Type 1 – 120ksi - carbon, carbon boron, alloy, or alloy boron steel
- Type 1 – 150ksi – alloy or alloy boron steel
- Type 3 – weathering Steel
|
F3125 Chemical Requirements
| Heat Analysis |
120ksi Type 1, % |
150ksi Type 1, % |
150ksi Type 3, % |
| Carbon |
0.30 – 0.52 |
0.30 – 0.48 |
0.30 – 0.53 |
| Manganese |
0.60 min |
0.60 min |
0.60 min |
| Phosphorus |
0.035 max |
0.035 max |
0.035 |
| Sulfur |
0.040 max |
0.040 max |
0.040 |
| Silicon |
0.15 – 0.30 |
- |
|
| Boron |
0.003 max |
0.003 max |
|
| Copper |
- |
- |
0.20 – 0.60 |
| Nickel |
- |
- |
0.20* min |
| Chromium |
- |
- |
0.45 min |
| Molybdenum |
- |
- |
0.10* min |
- Additional footnotes and A325 type 3 chemistries not included here for brevity
- 150ksi type 3- Either Nickel or Molybdenum must be present
|
F3125 Mechanical Properties
| Grade |
Tensile, ksi |
Yield, ksi min |
Elongation, % min |
RA, % min |
| 120ksi (A325/F1852) |
120 min |
92 |
14 |
35 |
| 150ksi (A490/F2280) |
150-173 |
130 |
14 |
40 |
F3125 Marking Requirements & Matching Components
|
120ksi, Type 1 |
120ksi, Type 3 |
150ksi, Type 1 |
150ksi, Type 3 |
| Marking |
A325 |
A325 |
A490 |
A490 |
| Nut, Plain |
A563 DH |
A563 DH3 |
A563 DH |
A563 DH3 |
| Nut, Coated |
A563 DH |
A563 DH3 |
A563 DH |
A563 DH3 |
| Washer |
F436-1 |
F436-3 |
F436-1 |
F436-3 |
- A194 2H nuts are an acceptable substitute for A563 DH nuts
- Suitable plain finish nut alternatives can be found in the full F3125 text
- Supplementary requirements S1 and S2 have special marking requirements.
|