ASTM A1008 Steel Sheet for Cold Forming

1. Definition and Scope

ASTM A1008/A1008M is the North American standard specification for steel sheet, cold-rolled, carbon, structural, high-strength low-alloy (HSLA), high-strength low-alloy with improved formability (HSLAS-F), solution hardened (SHS), and bake hardenable (BHS) grades. It covers material produced by cold reduction of hot-rolled pickled coil to final thickness, supplied in coils or cut lengths with thicknesses typically from 0.36 mm (0.014 in.) to 5.8 mm (0.229 in.).

ASTM A1008 is the primary feedstock specification for roll forming operations in the United States, Canada, and Mexico. Building products (studs, tracks, purlins), storage rack, solar mounting, and industrial profiles reference A1008 grades on purchase orders and engineering drawings. The standard defines chemical composition limits, mechanical property requirements, surface finish descriptions, and ordering information. Dimensional tolerances for thickness, width, and flatness are governed by the general requirements standard ASTM A568/A568M, which A1008 references.

Roll forming manufacturers specify A1008 grade, thickness, width, surface finish, and edge condition when ordering coil from service centers or directly from steel mills. The grade selection balances yield strength (structural capacity of the finished profile), elongation (formability at bend radii), and surface appearance (visible vs hidden applications). Service centers slit master coils to roll forming width and supply with mill test reports certifying conformance to the ordered A1008 grade and A568 dimensional tolerances.

2. Steel Grades and Types

ASTM A1008 organizes grades into type categories based on strength level and intended forming severity. Each type contains numbered grades with defined minimum mechanical properties.

2.1 Commercial Steel (CS)

2.2 Drawing Steel (DS, DDS, EDDS)

2.3 Structural HSLA Grades (HSLAS)

Grade numbers in brackets indicate approximate minimum yield strength in MPa. Higher HSLAS grades provide greater structural capacity per unit weight in roll-formed profiles but require larger internal bend radii (typically 2–4× material thickness vs 1× for CS Type B) and more forming stands to distribute bending strain.

3. Mechanical Properties

Mechanical properties in ASTM A1008 are measured on longitudinal test specimens taken from the finished cold-rolled sheet. Properties apply to the as-rolled condition before any subsequent coating or forming. Roll forming is a cold forming process that work-hardens the strip at bend radii, increasing local yield strength by 10–30% depending on bend ratio and number of forming passes.

3.1 Typical Roll Forming Bend Radii by Grade

Where t is material thickness. Radii below the minimum may cause cracking on the outer bend surface, particularly on cut edges and pre-punched holes near bend lines.

3.2 Hardness and Forming Load

3.3 Bake Hardenable and Solution Hardened Grades

Mechanical property test frequency per ASTM A1008 requires one test per heat treat batch for production coils. Roll forming manufacturers receiving mill test reports verify that certified yield and tensile values fall within the ordered grade limits before releasing coil to production.

4. Surface Finish and Quality

ASTM A1008 defines surface finish categories that describe the texture and appearance of the cold-rolled surface. Surface finish affects roll forming friction, marking tendency, and suitability as a substrate for coating or painting.

4.1 Edge Condition

5. Designation System

ASTM A1008 product ordering uses a combination of standard reference, grade name, dimensions, surface finish, and edge condition. The complete designation appears on mill test reports and purchase orders.

5.1 Ordering Information Components

5.2 Worked Ordering Examples

6. Roll Forming Process Considerations

Processing A1008 on roll forming lines requires attention to grade-specific behavior in springback, surface marking, and thickness tolerance response. ASTM A568 thickness tolerances for cold-rolled sheet require roll gap adjustment when coil-to-coil thickness variation exceeds 0.03 mm on light gauge.

6.1 Grade-Specific Process Parameters

Uncoated A1008 (No. 2B finish) runs with standard tool steel rolls. For painted or galvanized A1008 (ordered per ASTM A653 or A792 with A1008 substrate), roll surfaces are polished or coated to prevent marking. Oil film from mill application reduces friction; excessive oil causes slip in driven stands.

6.2 Weldability and Pre-Punched Profiles

7. Roll Forming Applications

ASTM A1008 grades map to specific roll-formed product categories across North American construction, storage, and industrial markets.

When A1008 is specified as the substrate for galvanized product, the coating specification (ASTM A653 for zinc, ASTM A792 for aluminum-zinc) is stated separately. The combined order references both standards: substrate per A1008, coating per A653/A792. Mill test reports document mechanical properties of the substrate and coating mass of the coated product.

Chemical composition limits in ASTM A1008 Table 2 constrain carbon, manganese, phosphorus, and sulfur content for each grade type. CS grades allow maximum carbon of 0.15%; HSLAS grades permit microalloy additions (Nb, V, Ti) that achieve strength through precipitation hardening rather than carbon increase. Roll forming tool wear correlates with hardness and tensile strength; HSLAS 70 feedstock may reduce roll life by 30–40% compared to CS Type B at equivalent production volume, requiring hardened roll materials and more frequent regrinding schedules.