Grade A490 structural bolts
A490 bolting: coating, components and documentation are assessed against the applicable specification rather than inherited from A325.
- Reference
- ASTM F3125/F3125M — 26
- Configuration
- To specification and drawing
- Dimensions
- Specify units and tolerances
- Supply
- Confirm feasibility and documents
Technical drawing and dimensions to specify
Family selection guide. The drawing only identifies dimensions to specify; it does not identify a certified item, an available size range or a complete assembly. Final geometry and dimensions must match the approved drawing.
Dimensional data for the request
| Symbol | Required information | Units |
|---|---|---|
| d | Nominal thread and pitch | mm or inches, specify |
| L | Under-head length of the illustrated hex bolt | mm or inches, specify |
| b | Threaded length | mm or inches, specify |
Attach the dimensional standard or drawing, tolerances, quantity and configuration. Mechanical properties and grades appear below; they are not geometric dimensions.
Materials, grades and technical requirements
A325 or A490: key differences
| Characteristic | A325 | A490 |
|---|---|---|
| Product | Heavy Hex | Heavy Hex |
| Minimum tensile strength · inch series | 120 ksi | 150 ksi |
| Current specification | F3125/F3125M | F3125/F3125M |
| Specify | Type, dimensions, nut, washer, finish | Type, dimensions, nut, washer, permitted coating |
A490 is not an automatic replacement for A325. Joint resistance, ductility, components and installation must match the design. These values are neither allowable stresses nor tightening torques.
Heavy Hex, Twist-Off and Type
Heavy Hex identifies the head geometry. F1852 and F2280 identify Twist-Off configurations within F3125. Type 1 and Type 3 distinguish material types; Type 3 concerns weathering steel, not stainless steel.
Dimensions, thread and tightening
The inch Heavy Hex series covers diameters from ½″ to 1½″. Select length and thread position for the joint thickness and shear plane. Specify the required dimensional standard; A325M/A490M are not nominal conversions of inch products.
Nuts, washers and coatings
Specify ASTM A563 nuts and ASTM F436 washers compatible with grade, Type and finish. A coating used for A325 is not automatically permitted for A490. For pretensioned joints, request the assembly and relevant installation instructions.
Grade-specific coating review
State the specified finish, coating specification and any tests. Treatments or component combinations used for A325 are not automatically transferred to A490.
Identify the required assembly
Include type, style, thread and dimensions, together with the nut and washer required by the project. Add quantity, delivery timing and documentation requirements.
Technical documentation
Dueemme technical sheet
Download technical PDF ↓Assembly and traceability
Lot, markings, component list and conformity documents relevant to the supply.
EN 10204 3.1 · DoP · CoC
State the required documents. Applicability and availability are confirmed during enquiry review.
Testing and coatings
Dimensional reports, mechanical tests, coating reports and ROCAP where applicable to the specification.
Application sectors
Steelwork, structures and infrastructure.
Dueemme industries →Have a structural or ASTM specification?
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