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FULLERKREG supplies high-strength Pozi (Pozidriv) pan head machine screws conforming to GB818-2016 and ISO 7045. Manufactured from alloy steel 10B21 (boron-alloyed medium carbon steel) and heat-treated to property class 8.8, then finished with a trivalent zinc chromate (Zinc Cr3) coating. These screws deliver twice the tensile strength of standard Class 4.8 fasteners, making them the preferred choice for structural, mechanical, and high-load assemblies where both strength and corrosion protection are required.
| Product Name | Pozi Pan Head Machine Screws |
| Drive Type | Pozidriv (Pozi / Type Z) |
| Head Type | Pan Head (Cylindrical low-profile domed head) |
| Standards | GB818-2016 / ISO 7045 |
| Material | Alloy Steel 10B21 (Boron-alloyed medium carbon steel) |
| Property Class | 8.8 |
| Heat Treatment | Quenched & Tempered (Q&T) |
| Surface Treatment | Zinc Plated — Trivalent Chromate (Cr3) Passivation, RoHS Compliant |
| Coating Thickness | ≥ 5 µm (standard); ≥ 8 µm available on request |
| Salt Spray Resistance | ≥ 72 hours (white rust) per ISO 9227 |
| Size Range | M3 – M10 |
| Length Range | 5 mm – 80 mm |
| Thread | Metric Coarse Thread (ISO 68-1) |
| Tolerance | 6g (thread) per ISO 965-1; after plating per ISO 4042 allowance |
| RoHS Compliance | Yes — Cr3 (trivalent) chromate, hexavalent chromium (Cr6) free |
| Brand | FULLERKREG |
| [ Product Image 1 ] | [ Product Image 2 ] | [ Product Image 3 ] | [ Product Image 4 ] |
All dimensions in millimeters (mm). Verified against GB818-2016 and ISO 7045 standard tables. Note: nominal dimensions apply to the uncoated part; zinc plating adds ≤ 0.013 mm per side to head and shank diameters.
| Thread d |
Pitch p (mm) |
Head Dia. dk max (mm) |
Head Height k max (mm) |
Drive No. (Pozi) |
Drive Depth m min (mm) |
Drive Width b ref (mm) |
Length Range l (mm) |
Unit Weight (g / pc, ref.) |
|---|---|---|---|---|---|---|---|---|
| M3 | 0.50 | 6.0 | 2.4 | Z1 | 1.0 | 3.5 | 5 – 30 | 0.25 – 1.55 |
| M3.5 | 0.60 | 7.0 | 2.6 | Z2 | 1.2 | 3.9 | 5 – 35 | 0.42 – 2.58 |
| M4 | 0.70 | 8.0 | 3.1 | Z2 | 1.4 | 4.6 | 5 – 40 | 0.63 – 4.35 |
| M5 | 0.80 | 10.0 | 3.7 | Z2 | 1.6 | 5.7 | 6 – 50 | 1.15 – 8.80 |
| M6 | 1.00 | 12.0 | 4.6 | Z3 | 2.0 | 6.8 | 8 – 60 | 2.30 – 16.10 |
| M8 | 1.25 | 16.0 | 6.0 | Z3 | 2.5 | 9.2 | 10 – 80 | 5.72 – 39.50 |
| M10 | 1.50 | 20.0 | 7.5 | Z4 | 3.0 | 11.5 | 12 – 80 | 11.45 – 67.50 |
* Unit weight values are reference only, calculated for alloy steel (density ≈ 7.85 g/cm³) including zinc coating. Actual weight may vary slightly by length and manufacturing tolerance. Full per-length weight tables available on request.
| Thread | Standard Lengths Available (mm) |
|---|---|
| M3 | 5, 6, 8, 10, 12, 16, 20, 25, 30 |
| M3.5 | 5, 6, 8, 10, 12, 16, 20, 25, 30, 35 |
| M4 | 5, 6, 8, 10, 12, 16, 20, 25, 30, 35, 40 |
| M5 | 6, 8, 10, 12, 16, 20, 25, 30, 35, 40, 45, 50 |
| M6 | 8, 10, 12, 16, 20, 25, 30, 35, 40, 45, 50, 55, 60 |
| M8 | 10, 12, 16, 20, 25, 30, 35, 40, 45, 50, 55, 60, 70, 80 |
| M10 | 12, 16, 20, 25, 30, 35, 40, 45, 50, 55, 60, 70, 80 |
10B21 is a boron-alloyed medium carbon steel widely used for high-strength fasteners. The addition of boron (0.0005–0.003%) significantly improves hardenability, allowing Class 8.8 mechanical properties to be achieved with lower carbon content compared to plain carbon steels — resulting in better toughness, weldability, and consistent heat treatment response.
| Element | Composition (wt%) |
|---|---|
| Carbon (C) | 0.18 – 0.23% |
| Manganese (Mn) | 0.70 – 1.00% |
| Silicon (Si) | ≤ 0.35% |
| Phosphorus (P) | ≤ 0.030% |
| Sulfur (S) | ≤ 0.030% |
| Boron (B) | 0.0005 – 0.003% |
| Density | ≈ 7.85 g/cm³ |
| Property | Value / Specification | Standard Reference |
|---|---|---|
| Property Class | 8.8 | ISO 898-1 |
| Min. Tensile Strength (Rm min) | 800 MPa | ISO 898-1 |
| Min. Yield Strength / Proof Load (Rp0.2 / Sp) | 640 MPa | ISO 898-1 |
| Elongation after fracture (A) | ≥ 12% | ISO 898-1 |
| Vickers Hardness | 245 – 335 HV | ISO 898-1 |
| Rockwell Hardness | 22 – 32 HRC | ISO 898-1 |
| Heat Treatment | Quenched & Tempered (Q&T), min. tempering temp. 425°C | ISO 898-1 |
| Stress Ratio (Rp0.2 / Rm) | 0.80 | ISO 898-1 |
| Parameter | Specification | Standard Reference |
|---|---|---|
| Plating Type | Electrolytic Zinc | ISO 4042 |
| Chromate Treatment | Trivalent Chromate (Cr3) — Silver / Blue-bright | ISO 4520 / RoHS |
| Coating Thickness | ≥ 5 µm (standard); ≥ 8 µm on request | ISO 4042 Class Fe/Zn 5 |
| Salt Spray Resistance | ≥ 72 h to white rust; ≥ 120 h available | ISO 9227 |
| Appearance | Silver / blue-white, uniform bright finish | — |
| RoHS Compliance | Yes — Hexavalent chromium (Cr6) free | EU RoHS 2011/65/EU |
| REACH Compliance | Compliant — no SVHC above threshold | EU REACH 1907/2006 |
| Hydrogen Embrittlement Relief | Baking at 200°C / 4 h post-plating (mandatory for Class 8.8 per ISO 4042) | ISO 4042 / ISO 15330 |
* Important: Class 8.8 fasteners are susceptible to hydrogen embrittlement during electroplating. FULLERKREG applies mandatory post-plating baking (de-embrittlement) per ISO 4042 to eliminate this risk.
| Property | Class 4.8 (Standard) | Class 8.8 (This Product) |
|---|---|---|
| Min. Tensile Strength | 420 MPa | 800 MPa |
| Proof Load / Yield | 310 MPa | 640 MPa |
| Hardness | 130–220 HV | 245–335 HV |
| Heat Treatment | None required | Quenched & Tempered |
| Typical Application | Light-duty, general assembly | Structural, high-load, mechanical |
| Application / Requirement | Recommendation |
|---|---|
| Structural & load-bearing assemblies | Class 8.8 — 800 MPa tensile, suitable for high-stress joints |
| Machinery & equipment manufacturing | M4–M10; Q&T alloy steel for vibration and fatigue resistance |
| Automotive body & chassis components | Class 8.8 Cr3 BZP — RoHS compliant, high strength, corrosion protected |
| Electronics & precision enclosures (high torque) | M3–M5; Pozi drive resists cam-out under power tool assembly |
| Replacement for Class 4.8 in upgraded designs | Same ISO 7045 geometry — drop-in upgrade, no tooling change |
| Indoor / light outdoor with corrosion protection | Zinc Cr3 — ≥ 72 h salt spray, adequate for most industrial environments |
| Marine / severe corrosive environments | Consider A4 stainless steel grades for superior corrosion resistance |
GB818-2016 is the Chinese national standard for cross recessed pan head screws, equivalent to and harmonized with ISO 7045:2011. Key standard provisions for this grade include:
| Thread Size | Standard Pack Qty (pcs) | MOQ (pcs) | Bulk Packaging |
|---|---|---|---|
| M3 – M4 | 1,000 / 2,000 | 500 | Poly bag in carton |
| M5 – M6 | 500 / 1,000 | 200 | Poly bag in carton |
| M8 – M10 | 100 / 200 / 500 | 100 | Poly bag in carton |
* Custom packaging, labeling, and mixed-size kitting available for wholesale orders. Contact FULLERKREG for bulk pricing and lead times.
🏭 Direct Manufacturer — Produced in-house with full process control: wire drawing, cold heading, thread rolling, heat treatment, and zinc plating.
📐 Standard Compliance — Every batch manufactured and inspected to GB818-2016 / ISO 7045 dimensional and ISO 898-1 mechanical requirements.
🔥 Heat Treatment Traceability — Q&T process records and hardness test reports available for Class 8.8 lots upon request.
🔬 Coating Quality Control — Salt spray testing per ISO 9227; de-embrittlement baking per ISO 15330 on every Class 8.8 production lot.
📦 Wholesale Ready — Flexible MOQ, bulk pricing tiers, and OEM/private label options for distributors and industrial buyers.
✅ RoHS & REACH Compliant — Cr3 trivalent chromate only; full compliance documentation available on request.
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