ASTM A283 Grade C Carbon Steel Plate — Factory Direct | Huaxia-Steel

ASTM A283 Grade C is a low-to-intermediate tensile strength carbon steel plate used for general structural applications where high strength is not required. It is one of the most economical structural grades and is widely used for tanks, buildings, bridges, and industrial equipment in warm-climate projects.

Huaxia-Steel supplies ASTM A283 Grade C carbon steel plate in a wide range of thicknesses and widths, with mill test certificates and optional third-party inspection for export orders.

Product Overview

ASTM A283 covers four grades (A, B, C, D) of structural-quality carbon steel plate. Grade C offers the best balance of strength, weldability, and cost among the four. It is produced by killed or semi-killed steelmaking and is supplied in the as-rolled condition.

Product form: Hot-rolled carbon steel plate.
Standard: ASTM A283 / A283M.
Condition: As-rolled.
Surface: As-rolled, shot-blasted, painted, or galvanized on request.

Specifications and Size Range

Parameter	Range
Thickness	2 mm to 300 mm
Width	1,000 mm to 4,000 mm
Length	2,000 mm to 18,000 mm
Tolerance	ASTM A6/A6M
Edge	Mill edge or cut edge
Bundle weight	5,000-20,000 kg typical

Mechanical Properties

Property	ASTM A283 Gr.C requirement
Yield strength	205 MPa min
Tensile strength	380-515 MPa
Elongation in 200 mm	22% min
Elongation in 50 mm	25% min

Chemical Composition

Element	Max % (plate thickness up to 50 mm)
C	0.24
Mn	0.90
P	0.035
S	0.040
Si	0.15-0.40
Cu	0.20

Grades Within ASTM A283

Grade	Yield MPa min	Tensile MPa	Use case
Gr.A	165	310-415	Very light structural
Gr.B	185	345-450	Light tanks and supports
Gr.C	205	380-515	General structural, tanks, buildings
Gr.D	230	415-550	Higher strength structural

Manufacturing Standards

ASTM A283 / A283M – Low and intermediate tensile strength carbon steel plates.
ASTM A6 / A6M – General requirements for rolled steel plates.
ASTM A20 / A20M – General requirements for pressure vessel plates (when dual certified).
ASTM A578 – Straight-beam ultrasonic examination.

Applications

Storage tanks and reservoirs.
Low-rise building frames and roof trusses.
Industrial platforms and walkways.
Bridge components in non-critical locations.
General fabrication and welded structures.
Base plates, gussets, and brackets.
Agricultural and mining equipment bodies.

Quality Assurance

Each plate order is verified before shipment:

Chemical analysis by spectrometer.
Tensile testing for yield, tensile strength, and elongation.
Dimensional inspection per ASTM A6.
Visual surface inspection.
Ultrasonic testing available on request.
MTC to EN 10204 3.1 as standard.
Third-party inspection by SGS, BV, Intertek, or TUV available.

Packaging and Shipping

Anti-rust oil or VCI coating.
Steel strapping and edge protectors.
Wooden separators for thin plates.
Clear marking with heat number, grade, dimensions, and standard.
Bulk vessel or container loading with supervision.

Thickness and Width Availability

Thickness range	Typical width	Typical length	Common use
2-6 mm	1,000-2,000 mm	2,000-6,000 mm	Sheet metal work, tanks, panels
6-25 mm	1,500-2,500 mm	6,000-12,000 mm	Platforms, flooring, brackets
25-80 mm	2,000-3,000 mm	6,000-12,000 mm	Heavy structures, machine bases
80-300 mm	2,000-4,000 mm	6,000-18,000 mm	Thick foundation plates, flanges

Weldability and Fabrication

A283 Grade C is a low-carbon steel with good weldability. Common arc-welding processes such as SMAW, GMAW, FCAW, and SAW are all suitable. Preheat is generally not required below 25 mm thickness at ambient temperatures above 10 degrees C. For thicker plates or high-restraint joints, preheat to 75-100 degrees C is recommended. Post-weld heat treatment is usually unnecessary unless the code requires stress relief.

Surface Treatment Options

Shot blasting: Removes mill scale and prepares for painting.
Primer coating: Red rust primer or epoxy primer for corrosion protection.
Hot-dip galvanizing: Zinc coating for outdoor structures.
Cutting: Oxy-fuel, plasma, laser, or waterjet cutting to shape.
Edge preparation: Beveling for welding or chamfering for safety.

Comparison with A36 and A283 Gr.D

Grade	Yield MPa min	Tensile MPa	Relative cost	Best use
A283 Gr.C	205	380-515	Lowest	Tanks, light structural
ASTM A36	250	400-550	Moderate	Buildings, bridges, machinery
A283 Gr.D	230	415-550	Moderate	Higher strength tanks

Order Example

A typical order might read: “ASTM A283 Grade C carbon steel plate, 10 mm x 2,000 mm x 6,000 mm, 30 tonnes, as-rolled, mill edge, MTC to EN 10204 3.1.” For cut-to-size requirements, provide a cutting list with quantities per size to optimize material utilization.

Stock and Mill Production Strategy

For common thicknesses such as 6 mm, 8 mm, 10 mm, 12 mm, 16 mm, 20 mm, and 25 mm, Chinese mills maintain regular stock that can be shipped within one to two weeks. For thicknesses above 80 mm or widths above 3,000 mm, production is typically made-to-order with longer lead times. We can advise whether your requirement is best filled from stock or by mill order.

Comparison with A285 and A36

ASTM A283 Gr.C, A285 Gr.C, and A36 are all low-carbon structural plates, but they differ in strength and intended use. A283 Gr.C has the lowest yield strength at 205 MPa and is intended for general structural applications. A285 Gr.C has similar chemistry but is oriented toward pressure vessels and tanks. A36 is stronger with 250 MPa yield and is the most common structural grade in North America. For non-pressure tanks and light structures in warm climates, A283 Gr.C offers the lowest material cost.

Quality Tolerances

Dimensional tolerances for A283 Gr.C plate follow ASTM A6/A6M. Thickness tolerance depends on the ordered thickness and width. Width and length tolerances are typically plus 6 mm and minus 0 mm. Flatness tolerances vary by thickness and yield strength. If your application requires tighter tolerances, specify ASTM A6 restricted thickness tolerance or plan for additional grinding and machining.

Processing Services Available

To reduce your fabrication workload, we offer a range of in-house and partnered processing services:

Plasma, laser, and oxy-fuel cutting to shape.
CNC machining of holes, slots, and pockets.
Drilling and tapping.
Beveling for weld edge preparation.
Rolling and forming for tanks and cylinders.
Shot blasting and priming.

Ordering and Delivery

Thickness range	Minimum order	Typical lead time
2-12 mm	10 tonnes	2-3 weeks
12-50 mm	10 tonnes	3-4 weeks
50-150 mm	20 tonnes	4-6 weeks
150-300 mm	Negotiable	6-8 weeks

Documentation and Traceability

Each plate is marked with the heat number and tracked through production. We provide mill test certificates showing chemical composition, mechanical properties, and dimensional results. Third-party inspection and EN 10204 3.2 certification are available for projects requiring independent verification.

Inspection and Testing Details

Every heat of A283 Gr.C plate is tested for tensile properties and chemical composition. For thickness above 40 mm, additional through-thickness testing can be arranged. Ultrasonic testing per ASTM A578 Level B is available to detect internal laminations. Surface inspection is performed visually, and dimensional checks follow ASTM A6 tolerances unless tighter tolerances are specified.

Frequently Asked Questions

Is A283 Gr.C plate pressure rated?

No. A283 is a structural plate, not a pressure vessel grade. Use A285, A516, or similar for pressure service.

Can A283 Gr.C be galvanized?

Yes, it can be hot-dip galvanized for outdoor structures.

What is the maximum thickness available?

We can supply up to 300 mm by mill order.

Does A283 Gr.C meet A36 requirements?

No. A36 has higher minimum yield strength. A283 Gr.C can sometimes substitute where lower strength is acceptable, but the specification must be reviewed.