Steel Coil & Strip Specification & Procurement Guide
Steel coils and strips serve as foundational raw materials for stamped components, roll-formed profiles, welded pipes, and structural enclosures. Selecting the correct steel variant requires balancing mechanical performance, tight thickness tolerances, surface quality, and post-processing behavior (such as deep drawing, bendability, and weldability).
Unprocessed material deviations—such as edge wave, center buckle, excessive thickness variation, or inconsistent yield strength—directly lead to die wear, press downtime, roll-forming misalignment, and coating failures.
This guide provides technical parameters, international standard cross-references, manufacturing limits, and quality verification criteria to assist purchasing managers, metallurgical engineers, and supply chain specialists in evaluating, specifying, and sourcing steel coil and strip products.
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![Slit Steel Coil]()
Slit Steel CoilSlit steel coils are produced by longitudinally shearing wide master coils (Hot Rolled, Cold Rolled, Galvanized, or Stainless) into specific narrower strip widths using high-precision rotary shear -
![High Carbon Steel Strip]()
High Carbon Steel StripHigh carbon steel strips (carbon content 0.60% - 1.05%) are cold-rolled narrow steel products engineered for high-wear and high-stress applications. -
![Spring Steel Strip]()
Spring Steel StripPrecision-rolled spring steel strip engineered for applications demanding high yield strength, fatigue resistance, and controlled elastic recovery. -
![Tinplate Coil]()
Tinplate CoilElectrolytic Tinplate (ETP) coil consists of cold-rolled low-carbon steel substrate electroplated with pure tin on both sides. -
![Electrical Steel Coil]()
Electrical Steel CoilElectrical steel coil (silicon steel) is a soft magnetic iron-silicon alloy engineered for electromagnetic energy conversion. The addition of silicon increases electrical resistivity, reduces eddy -
![Galvalume Steel Coil]()
Galvalume Steel CoilGalvalume steel coil (55% Aluminum, 43.4% Zinc, and 1.6% Silicon alloy coating) provides dual corrosion protection combining the barrier resistance of aluminum with the sacrificial galvanic
We produce and supply five core categories of steel coils and strips:
Hot Rolled (HR / HRP&O): Unprocessed hot-rolled or pickled and oiled coils for structural and stamping applications.
Cold Rolled (CR / CA): Cold-reduced coils with close dimensional tolerances and clean surfaces for drawing and painting.
Hot-Dip Galvanized (GI / HDGL)
Continuous zinc-coated coils providing cathodic corrosion protection.
Zinc-Aluminum-Magnesium (ZAM / ZM)
High-corrosion-resistant alloy-coated steel with self-healing cut-edge protection.
Prepainted Steel (PPGI / PPGL)
Color-coated coils with organic topcoats over galvanized or galvalume substrates.
|
Product Category |
Processing Method / Coating Type |
Thickness Range |
Width Range |
Core Surface / Processing Characteristics |
|
Hot Rolled (HR) & Pickled & Oiled (P&O) |
Hot thermo-mechanical rolling; mill scale removal via hydrochloric acid pickling + rust-preventive oiling |
1.2 mm - 25.0 mm |
600 mm - 2,000 mm |
Mill scale removed; smooth matte surface; ready for stamping, blanking, or direct painting without mechanical descaling |
|
Cold Rolled Full Hard (CRFH) & Annealed (CRCA) |
Cold reduction of HR coil; batch or continuous annealing |
0.15 mm - 3.0 mm |
600 mm - 1,500 mm |
Close dimensional tolerances (+/-0.02 mm); uniform grain structure; high surface cleanability for electroplating and automotive painting |
|
Hot-Dip Galvanized (GI / HDGL) |
Continuous hot-dip zinc coating; zero, minimum, or regular spangle |
0.30 mm - 6.0 mm |
600 mm - 1,800 mm |
Cathodic protection; coating mass Z60 to Z600 g/m²; passivated or oiled surface treatments |
|
Zinc-Aluminum-Magnesium (ZAM / ZM) |
Hot-dip coating (typically Zn + 11% Al + 3% Mg or Zn + 3% Al + 2% Mg) |
0.50 mm - 6.0 mm |
600 mm - 1,600 mm |
Self-healing cut edge protection; corrosion resistance 5x to 10x higher than standard GI in salt spray tests; ideal for harsh environments |
|
Prepainted Steel (PPGI / PPGL) |
Continuous coil coating; PE, SMP, HDP, or PVDF topcoats over GI / GL base |
0.18 mm - 1.5 mm |
600 mm - 1,250 mm |
Multi-layer primer and finish coat (15 µm - 35 µm dry film thickness); controlled gloss and color matching (RAL system) |
Key Product Characteristics
Mechanical Consistency
Yield strength, tensile strength, and total elongation are controlled within tight bands per heat charge. For deep-drawing applications (e.g., DC04 / DD13), low yield ratios (Rs/Rm) and high r-values (plastic strain ratio) prevent necking and wrinkling in multi-stage press lines. High-strength structural grades (e.g., S355MC, S700MC) utilize micro-alloying (Nb, V, Ti) to yield fine grain structures with high impact toughness at low temperatures down to -40°C.
Edge & Strip Geometry
Mill Edge vs. Slit Edge: Slit strips feature precise width tolerances (+/-0.10 mm) with micro-burr control (burr height < 8% of nominal thickness) using rotary shearing knives.
Camber & Flatness: Tension leveling lines ensure strip camber remains below 1.5 mm per 2,000 mm straight line length. Flatness tolerances are held within 5 to 10 I-units to eliminate center buckle and edge waves before feed-in to roll-forming machines or laser cutters.
Coating Integrity & Cut-Edge Protection
Galvanized (GI): Zinc skin forms a physical barrier and sacrificial anode. Uniform coating thickness ensures bendability around tight radii (0T - 2T) without flaking or micro-cracking.
Zinc-Aluminum-Magnesium (ZAM): During exposure to moisture and atmospheric chlorides, the magnesium and aluminum in the zinc coating form a dense, stable protective layer consisting of simonkolleite [Zn5(OH)8Cl2·H2O]. This layer flows over and seals cut edges, preventing red rust lateral creep without requiring post-fabrication hot-dip re-galvanizing.
Key Specifications
Coil Dimensional Parameters
Inside Diameter (ID)
508 mm (20 in) or 610 mm (24 in) standard mandrel fit.
Outside Diameter (OD)
Up to 2,000 mm based on unwinder line capacity.
Coil Weight
2.0 to 28.0 Metric Tons.
|
Parameter |
Standard Range / Option |
Engineering Tolerance / Standard |
|
Thickness Range |
Cold Rolled / Coated: 0.15 mm - 3.0 mm Hot Rolled: 1.2 mm - 25.0 mm |
EN 10131 (CR), EN 10051 (HR), ASTM A568 Tighter options: +/-0.02 mm (half-standard tolerance) |
|
Width Range |
Mill Coils: 600 mm - 2,000 mm Slit Strips: 20 mm - 599 mm |
Mill Edge: +10/-0 mm Slit Edge: +/-0.10 mm to +/-0.30 mm |
|
Coil Inside Diameter (ID) |
508 mm (20") / 610 mm (24") |
Standard mandrel fit for decoiling lines |
|
Coil Outside Diameter (OD) |
900 mm - 2,000 mm |
Customized based on unwinder weight capacity |
|
Coil Weight |
2.0 Metric Tons - 28.0 Metric Tons |
Slit coils supplied as eye-to-sky or eye-to-wall pallets |
|
Coating Mass (GI) |
Z60 g/m² - Z600 g/m² (total both sides) |
EN 10346, ASTM A653 / A653M |
|
Coating Mass (ZAM) |
ZM90 g/m² - ZM430 g/m² |
EN 10346 (e.g., ZM120, ZM310), ASTM A1046 |
|
Paint Film (PPGI/PPGL) |
Top: 15 µm - 35 µm; Back: 5 µm - 15 µm |
EN 13523 series, ASTM A755 |
|
Surface Finish |
Bright, Matt, Normal Spangle, Zero Spangle, Smooth |
Ra 0.6 µm - 1.9 µm for CR sheet drawing applications |
|
Surface Oil Treatment |
Dry, Light Oiling (0.5 - 1.0 g/m²), Heavy Oiling (1.5 - 3.0 g/m²) |
Dosatron / electrostatic oiling (rust prevention up to 6 months) |
Grades & Standards
The table below cross-references standard grades across major international specifications (EN, ASTM, JIS) for proper material equivalency verification.
|
Material Class |
EN Standard |
ASTM Standard |
JIS Standard |
Typical Yield Strength (MPa) |
Typical Tensile Strength (MPa) |
|
Commercial Quality (CQ) |
DC01 / S235JR |
ASTM A1008 CS Type B / ASTM A36 |
SPCC / SS400 |
140 - 280 |
270 - 440 |
|
Drawing / Deep Drawing |
DC03 / DC04 / DD13 |
ASTM A1008 DS Type B / DDS |
SPCD / SPCE |
140 - 210 |
270 - 350 |
|
Extra Deep Drawing (EDD) |
DC05 / DC06 |
ASTM A1008 EDDS |
SPCF / SPCG |
110 - 170 |
260 - 330 |
|
Structural Steel (Low/Med) |
S250GD / S350GD |
ASTM A653 Grade 33 / Grade 50 |
SGCC / SGLCC |
250 - 350 |
330 - 480 |
|
High Yield Structural (HR) |
S355MC / S420MC |
ASTM A1011 HSLAS Grade 50/60 |
SPHC / SPHT3 |
355 - 420 |
430 - 580 |
|
Ultra High Strength (SMM) |
S500MC / S700MC |
ASTM A1011 HSLAS Grade 80 |
SPFC 590 / 780 |
500 - 700 |
560 - 750+ |
|
Boiler & Pressure Vessel |
P235GH / P265GH |
ASTM A516 Grade 60 / Grade 70 |
SB410 / SB450 |
235 - 265 |
360 - 520 |
Applications
Solar Mounting Systems & Tracker Structures
Recommended Grade: ZAM (Zinc-Aluminum-Magnesium) ZM275 / ZM310, S350GD + ZM, S450GD + ZM.
Selection Rationale: Solar ground mounts and single-axis trackers undergo punching, roll forming, and outdoor exposure (C3 to C5 corrosive environments). ZAM provides cut-edge sacrificial protection, eliminating post-galvanizing costs for C/U-channels and torque tubes.
Pre-Engineered Buildings (PEB) & Roofing
Recommended Grade: Structural GI (S350GD + Z275), PPGI (AZ150 base with 25 µm PVDF/HDP paint system).
Selection Rationale: Roll-formed standing seam roof panels, Z/C purlins, and wall cladding require yield strength stability (> 350 MPa) to maintain span load-bearing performance without buckling under wind uplift.
Precision Steel Pipe & Tube Manufacturing
Recommended Grade: HRP&O S235JR / S355JR, CRCA DC01 / SPCC.
Selection Rationale: Consistent gauge thickness and slit edge squareness ensure stable high-frequency induction welding (ERW). Cleaned, scale-free surfaces prolong mill roll tooling life and allow uniform chrome plating or powder coating on finished tubes.
Automotive & Heavy Machinery Components
Recommended Grade: High-Strength Low-Alloy (HSLA) S500MC / S700MC, Deep Drawing DC04 / DC06.
Selection Rationale: Chassis members, structural crossbeams, and complex stamped brackets require high yield strength for weight reduction alongside strict ductility limits (A80 >= 12% - 16%) to prevent cracking in forming dies.
Quality & Inspection
All production runs undergo mill testing and batch inspection protocol before dispatch:
Chemical Analysis (XRF / OES Spectrometry)
Heat chemistry verification against EN and ASTM ladle composition limits.
Mechanical Testing (Universal Tensile & Hardness)
Verification of Yield Strength (Rp0.2), Tensile Strength (Rm), Elongation (A80%), and Bend Test performance.
Dimensional & Surface Inspection
Continuous online laser thickness gauge monitoring across the coil length.
Width check, camber measurement, and micro-burr evaluation on slit strips.
Coating & Surface Verification
Triple-spot gravimetric testing for Zinc and ZAM coat weight (g/m²).
Cross-hatch adhesion, T-bend testing, and solvent rub (MEK) testing for PPGI.
Corrosion Resistance Testing (SST)
Neutral Salt Spray (NSS) testing compliant with ASTM B117.
Standard Documentation Issued per Order
- Mill Test Certificate (MTC): Fully compliant with EN 10204 3.1 (includes ladle chemical analysis, mechanical test results, grain size where applicable, and coating mass per heat).
- Dimensional Inspection Report: Continuous thickness chart log and slit width verification sheet.
- Coating Mass Verification: Gravimetric measurement report (ISO 1460 / ASTM A90).
Supply & Customization Options
We offer custom processing, slitting, packaging, and logistical options to match buyer production lines and transport modes:
Processing Services
Precision Slitting: Widths down to 20 mm, minimum width tolerance +/-0.10 mm.
Cut-to-Length (CTL) Sheets: Leveling and shearing into flat sheets (300 mm - 6,000 mm length) with diagonal tolerance within 1.0 mm.
Edge Conditioning: Mill edge, sheared edge, deburred edge, or rounded edge options available.
Export Packaging Systems
Eye-to-Sky (Vertical): Coil placed vertically on wooden skids, recommended for narrow slit strips.
Eye-to-Wall (Horizontal): Coil placed horizontally on wooden cradles, recommended for heavy master coils.
Protective Wraps: VCI (Volatile Corrosion Inhibitor) anti-rust paper wrap, inner HDPE plastic film, galvanized steel inner/outer ring protectors, and corrugated steel circumferential wraps.
Logistics & Incoterms
Incoterms Supported: FOB, CFR, CIF, DDP, DAP (handling customs clearance and inland trucking to warehouse/site).
What Buyers Should Provide
To receive an accurate technical quotation and lead-time estimate, submit the following engineering parameters with your RFQ:
Standard & Steel Grade
(E.g., EN 10346 S350GD + ZM310, or ASTM A653 CS Type B).
Product Dimensions
Nominal Thickness and acceptable tolerance range (e.g., 1.50 mm +/-0.03 mm).
Nominal Width (e.g., 1,250 mm master coil or 145 mm slit strip).
Coating Requirements
Coating Type (GI, ZAM, HDGL, PPGI) and mass/thickness (e.g., Z275 g/m², ZM120 g/m², Top 25 µm / Back 10 µm).
Surface Finish (e.g., Zero Spangle, Chromated, Oiled 1.0 g/m², Anti-fingerprint).
Coil Weight Restrictions:
Maximum / Minimum Coil Weight (e.g., Max 5.0 MT per slit coil or 15 - 20 MT master coil).
Inside Diameter requirement (508 mm or 610 mm).
Processing Intent & Application
(E.g., High-speed roll forming for solar purlins, deep drawing for automotive stamping, ERW pipe manufacturing).
Target Quantity & Delivery Terms
Total tonnage, batch sizes, destination port/city, and required Incoterms.
FAQ
Request a Quote
Submit your project requirements, technical drawings, or bill of materials to our engineering supply team for review and pricing:
Commercial Sales Team: sales@tjrsr.com
Engineering & Technical Support: info@tjrsr.com
Phone / WhatsApp: 86 13821826906
Headquarters: Unit 2102, Jingjin International Center, NO.18 Hejiang Road, Heping District, Tianjin, China
Please include your required grade, dimensions, target tonnage, and destination port to receive a formal quotation within 24 hours.
As one of the most professional steel coil & strip manufacturers and suppliers in China, we also support customized service. Please feel free to wholesale cheap steel coil & strip in stock here from our factory. For price consultation, contact us.
