JIS G3312 CGCC PPGI: The Industry Standard for Versatile Forming
Our JIS G3312 CGCC Prepainted Galvanized Steel Coils (PPGI) are manufactured to meet the high precision and quality consistency required by the Japanese Industrial Standards. As one of the most widely utilized grades in the international market, the CGCC (Commercial Grade) designation ensures a perfect balance between material strength and superior coating adhesion, making it ideal for a vast range of indoor and outdoor applications.
Understanding the JIS G3312 CGCC Specification
The JIS G3312 standard specifies the requirements for prepainted hot-dip zinc-coated steel sheets and strips. Our production process adheres to these specific material properties:
CGCC Grade (Commercial): Optimized for general forming, bending, and roll-forming. It provides the necessary ductility to create complex profiles—such as corrugated roofing sheets and sandwich panels—without compromising the zinc or paint layers.
Galvanized Substrate: Built on a hot-dip galvanized base (JIS G3302), providing a robust cathodic protection layer that prevents the spread of rust, even at cut edges.
Paint System Versatility: Available in diverse resin types including Polyester (PE), SMP, and PVDF, all applied via a precision continuous coating process.
Key Performance IndicatorsExceptional Adhesion:
Rated for 0T-3T bending, ensuring the paint film remains intact without peeling or cracking during severe fabrication processes.Hardness & Scratch Resistance: With a pencil hardness of $\geq$ H, our PPGI resists damage during transportation, handling, and installation.Corrosion Resistance: Tested via salt spray and UV accelerated weathering to ensure long-term color retention and structural integrity.
Technical Specifications (JIS G3312)
| Feature | JIS G3312 Requirement | Bomis Steel Performance |
| Base Metal Grade | CGCC (Commercial) | Prime Quality CGCC |
| Zinc Coating Mass | Z08 – Z27 (30g – 275g/$m^2$) | Fully Customizable |
| Paint Film Thickness | Top: 15-25μm / Back: 5-12μm | High Precision ($\pm 2\mu m$) |
| Pencil Hardness | $\geq$ H | Superior Surface Durability |
| T-Bend Test | No cracking or peeling | $\leq$ 3T |
| Impact Resistance | $\geq$ 500g $\times$ 50cm | Excellent Film Toughness |
JIS G3312 CGCC PPGI Coil Product Parameters
Commodity | JIS G3312 Prepainted Galvalume Steel Coil |
Base material | Hot dipped galvalume steel coil |
Weight | 3-8 Ton per Coil |
Package | waterproof paper, galvanized steel covered and steel strip packed |
Supply capacity | 3000 MT Per Month JIS G3312 Pre-painted Galvalume Steel Coil |
Top painting | 15~25μm |
Back painting | 5~7μm |
certification
product testing
After the products are completed, they will undergo strict inspections before being packaged.
Why Choose Bomis PPGI Steel Coils?
Superior Durability: Our coatings use high-quality pigments that resist fading and chalking for up to 15-20 years.
Precision Coating: We use advanced double-coat and double-bake (2C2B) processes to ensure uniform thickness and excellent adhesion.
Advanced Testing: Every batch undergoes rigorous testing, including the T-bend test, Pencil hardness test, and Salt spray test.
Customization: From matte finish to wood grain patterns, we provide versatile surface treatments to meet your architectural needs.
Product Showcase
FAQ about PPGI
1. What is the difference between ASTM A755 and standard PPGI?
ASTM A755 is a specific standard for exterior-grade prepainted steel used in roofing and siding. Unlike general-purpose PPGI, ASTM A755 strictly regulates the organic coating system (such as PVDF, SMP, or HDP) and its performance against UV radiation, chalking, and color fading. It ensures the material can withstand long-term atmospheric exposure without losing structural or aesthetic integrity.
2. Why is PVDF coating recommended for ASTM A755 exterior grade?
PVDF (Polyvinylidene Fluoride) is the gold standard for ASTM A755 applications. It provides the highest resistance to UV rays and chemical pollutants. If your project is in a high-sunlight or coastal area, PVDF ensures that the roofing or siding maintains its color and gloss for over 20-30 years, significantly outperforming standard Polyester (PE) coatings.
3. What zinc coating weight is required for ASTM A755 roofing steel?
ASTM A755 typically utilizes substrates compliant with ASTM A653 (Galvanized) or ASTM A792 (Galvalume). For exterior roofing, we recommend a minimum zinc coating of G60 ($180g/m^2$) or G90 ($275g/m^2$). The thicker the zinc layer, the better the sacrificial protection against edge corrosion and scratches.
4. Can ASTM A755 PPGI withstand severe roll-forming?
Yes. Our ASTM A755 coils are tested for superior flexibility. They typically achieve a T-bend rating of 0T to 2T, meaning the paint film will not crack or peel even when the steel is bent at 180 degrees. This is crucial for manufacturing complex roofing profiles, standing seam panels, and corrugated siding.
5.Are you a manufacturer or a trading company?
We are a factory with over 10 years of sales experience
6.How do you guarantee the quality?
1) Sourcing only from top-tier, certified mills.
2) Conducting our own rigorous in-house QC checks.
3) Providing a formal Mill Test Certificate and our quality warranty for every shipment.
