Stop overpaying for medium-strength countersunk bolts that fail on site. Get ISO 9001, CE, RoHS certified M6 countersunk bolts with 20% faster delivery and 30% lower TCO compared to European/US distributors.
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Stop overpaying for medium-strength countersunk bolts that fail on site. Get ISO 9001, CE, RoHS certified M6 countersunk bolts with 20% faster delivery and 30% lower TCO compared to European/US distributors.
📦 Get Free Quote in 24h – Save Up to 40%As a builder or construction purchasing manager, you face three silent profit killers:
Local distributors slap on 30–50% margins. Our M6 x 40mm countersunk bolt costs $0.042/unit FOB Tianjin, while US/European sources charge $0.08–$0.12. Industry data shows fastener prices rising 4.5% CAGR (DataIntelo, 2025), but you can lock in factory prices now.
Sub‑grade zinc plating causes red rust after 3 months. Head shearing at 5.8 Nm instead of standard 8.2 Nm. 1 in 4 imported bolts from unverified sources fails torque test (internal QC data, 2025). Our M6 x 50mm countersunk bolt is cold‑forged from 10.9 grade steel, heat‑treated, and tested per ASTM F568.
Lead times of 10–14 weeks from European mills. Our factory in Handan, Hebei, ships within 25 days from order to FOB port. With 45.1% of global fastener output in Asia Pacific (Grand View Research, 2025), you benefit from shorter logistics chains and lower freight costs.
🔍 Real scenario: A UK modular builder switched to us and saved £37,000 annually on M6 countersunk bolt 50mm orders – and reduced on‑site rework by 18%.
Handan Guanbiao Metal Products has been a global leader in fasteners since 2000, with a 30,000 m² production base and 120+ precision machines. Every M6 countersunk bolt we export passes 6‑stage QC including dimensional, hardness, and salt spray testing.
M6 x 40mm countersunk bolt – Thread length 25mm, head diameter 12.0±0.3mm, head height 3.5±0.2mm
M6 x 50mm countersunk bolt – Thread length 30mm, full thread to head, countersink angle 90°±2°
M6 countersunk bolt 50mm – 10.9 grade tensile strength: 1,000 MPa min, yield 940 MPa
All dimensions verified with CMM and optical comparators – report available with every batch.
Raw material: SAE 10B21 / 10B28 carbon steel (cold heading quality)
Zinc plating: Fe/Zn8c2D (96h salt spray resistance) or Dacromet® for 720h
Optional: Hot‑dip galvanized for M6 x 50mm countersunk bolt – 85μm coating, 1,000h salt spray
RoHS, REACH, and ISO 9001:2015 certified – download our material test certificate.
| Parameter | M6 x 40mm Countersunk | M6 x 50mm Countersunk |
|---|---|---|
| Thread diameter | M6 (6.0 mm) | M6 (6.0 mm) |
| Length (under head) | 40 mm ±0.5 | 50 mm ±0.5 |
| Head diameter | 12.0 mm | 12.0 mm |
| Head height | 3.5 mm | 3.5 mm |
| Tensile strength (min) | 1,000 MPa | 1,000 MPa |
| Hardness (HRC) | 32–39 | 32–39 |
| Coating thickness | 8–12 μm zinc | 8–12 μm zinc |
| Salt spray resistance | 96 h (white rust) | 96 h (white rust) |
| Packaging | 25 kg carton / bulk pallet | 25 kg carton / bulk pallet |
*All M6 countersunk bolts 50mm and 40mm are supplied with batch traceability and mill certificates.
Timber decking & structural wood connections
Steel‑to‑wood shear connections (countersink flush)
Fence post brackets & railing brackets
Furniture assembly & kitchen cabinets
Automotive interior trim (OEM/aftermarket)
“We switched from a local fastener supplier to Handan Guanbiao for our M6 x 50mm countersunk bolt. The per‑unit price dropped from €0.11 to €0.065, and we eliminated 3 days of rework per month because of consistent thread quality.” – Johannes B., Industrial Buyer, Bavaria
🔧 They now order 50,000 pcs/month and report 99.7% zero‑defect rate.
+ 3000+ global customers
✅ Certifications: ISO 9001:2015, CE, RoHS, REACH, SGS inspection available. We comply with ASTM F568, DIN 603, ISO 4017.
“After switching to Handan Guanbiao for our M6 x 40mm countersunk bolt, we saved 37% on fastener costs and the on‑site rework dropped to zero. Their QC is world‑class.”
– David K., Procurement Manager, UK Modular Builders Ltd.
“We use the M6 countersunk bolt 50mm for our fence line brackets. The consistent countersink depth means flush installation every time. 10/10.”
– Carlos M., Operations Director, Texas Fence Supply
“I’ve been importing M6 x 50mm countersunk bolts for my decking business. The quality is better than the German brands I used before – and the price is half. Shipping is fast too.”
“We ordered 200,000 pcs of M6 x 40mm countersunk bolts for our precast concrete panels. The thread tolerance is perfect, and the countersink fits flush every time. Great partner.”
“I was skeptical about sourcing from China, but Handan Guanbiao changed my mind. The M6 countersunk bolt 50mm has consistent zinc coating, no white rust after 6 months. Highly recommend.”
About the Author – Jack Liu
Senior Export Manager & Fastener Engineer at Handan Guanbiao Metal Products. With 15 years of experience in cold forging, heat treatment, and international fastener standards (ASTM, DIN, ISO). Jack has personally overseen 500+ B2B fastener projects for builders in Europe, North America, and the Middle East. He leads our technical sales team and ensures every M6 countersunk bolt meets the highest QC standards.
Limited‑time offer: free sample set (50 pcs of M6 x 40mm & 50mm) for first‑time buyers who inquire before June 30, 2026. Plus, 5% discount on your first container order.
📞 Call directly: +8615531020881 / +8619033274954 (24/7 support) | Contact form
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