Structural Bolts Overview - F3125 Family
ASTM F3125 consolidated the structural bolt specifications A325, A490, F1852 and F2280 into one standard in 2015. They clamp steel connections under RCSC installation rules.
F3125 grades
| Grade | Head | Tensile | Galvanizing |
|---|---|---|---|
| A325 | Heavy hex | 120 ksi min | Allowed (HDG or mechanical) |
| A490 | Heavy hex | 150 - 173 ksi | Not allowed; zinc-flake (F3393) only |
| F1852 | Round TC | 120 ksi min | Allowed |
| F2280 | Round TC | 150 - 173 ksi | Not allowed; zinc-flake (F3393) only |
Metric versions: A325M, A490M. Type 3 = weathering steel.
These tables carry the same figures as the printed sheet below.
The printed sheet
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Text version of this sheet
ASTM F3125 · structural bolt family overview
What it is
FIELD IDENTIFICATION
ASTM F3125 consolidated the structural bolt specifications A325, A490, F1852 and F2280 into one
standard in 2015. They clamp steel connections under RCSC installation rules.
MFG
MFG
A325
A490
A325
A325
A490
TC bolt
Heavy hex structural bolts and round-head TC
bolts
F3125 grades
Grade
Head
Tensile
Galvanizing
A325
Heavy hex
120 ksi min
Allowed (HDG or mechanical)
A490
Heavy hex
150 - 173 ksi
Not allowed; zinc-flake (F3393) only
F1852
Round TC
120 ksi min
Allowed
F2280
Round TC
150 - 173 ksi
Not allowed; zinc-flake (F3393) only
Metric versions: A325M, A490M. Type 3 = weathering steel.
Key points
Structural bolts are assemblies: bolt, nut and washer from compatible lots.
The current edition, ASTM F3125/F3125M-26, also covers a 144 ksi minimum-tensile grade in addition to the 120 ksi and 150 ksi grades.
Governing standards: ASTM F3125/F3125M-26; ASTM A563/A563M-26; ASTM F436; RCSC Specification. Editions shown are the latest confirmed as of September 2026. The
drawing and the governing standard always take precedence over this sheet.
torquing any fastener. Verify the current governing standard, project documents, OEM requirements, size, thread, coating and lot certification. To the fullest extent permitted by law, The Fastener App disclaims liability
arising from reliance on this reference.
Fastener Guide reference FG-A75797 · thefastenerapp.com/fastener-guide/technical-reference/structural-bolts-overview-f3125-family · © The Fastener App. Reference only — verify the current governing standard, drawing and manufacturer data before specifying or installing.
