Black Zinc-Plated Carriage Bolts Outdoor Corrosion-Resistant, Grade 8.8 Carbon Steel Round Head with Square Neck M5M6M7M9M11M14

Wide Compatibility.Available in both inch & metric sizes: 1/2″×3″, 5/16″, M3/M4/M5/M6/M8/M10/M12, length up to 160mm, suitable for global market demands.
Strong & Durable Materials.Made from grade 8.8 carbon steel and 304 stainless steel, high strength, anti-deformation, long service life.
Excellent Anti-Corrosion.Black oxide, black zinc plated, and galvanized finish options, ideal for outdoor use, weather-resistant and rust-proof.
Stable Installation Design. Cup square neck / mushroom head / large flat head structure prevents spinning during installation, firm and reliable.
Versatile Applications.Widely used in furniture, machinery, construction, outdoor facilities, assembly and general engineering.
Factory Direct Supply.In stock for fast delivery, accept wholesale orders, support small MOQs and customized sizes.

These carriage bolts feature a square neck design for anti-rotation during installation. Made of 8.8 grade carbon steel or 304 stainless steel, they come with black zinc, galvanized or black oxide finish for excellent rust resistance, perfect for outdoor use. Available in both inch and metric sizes (M3 to M12, 5/16″, 1/2″×3″, up to 160mm length), they are widely used in furniture, machinery, construction and general engineering.

Key Features

Technical Specifications

Basic Information

We are specialized in making fasteners cold heading die and punch rod, with 15 years of production experience, strong development ability and advanced manufacturing equipment

Brazilian Miner Vale SA

23 large-scale ball mills, Ø5.5×8.8m

Wengfu Phosphate Mine Project Phase II in Saudi Arabia (Ma'aden)

6 wet grinding rod mills, Ø4.6×6.7m

Vedanta Project in South Africa

1 SAG mill, Ø8.5×5.5m

Factory Country/Region

No.9 Longteng Road, Maoshan Industrial Zone, Jiangshan Town, Yinzhou District, Ningbo City, Zhejiang Province

Why Choose Ningbo Jiuyi Precision Mould Co., Ltd.

1. Professional Manufacturer Background
  
  We are a direct manufacturer focusing on precision mould, punch, fastener, stamped parts and hand tools, with stable and professional production capacity, ensuring you get products from the source without middlemen.
2. Strong Scale & Revenue Strength
  
  With 51–100 employees and annual revenue between US$50M–100M, we have stable capital strength, mature production management and reliable supply capacity to support long-term cooperation.
3. Established in 2023 – Modern & Flexible Enterprise
  
  As a company founded in 2023, we adopt new equipment, new management and new technology, with higher efficiency, stronger flexibility and faster response than traditional old factories.
4. Complete Product Range
  
  We provide one-stop supply:
- Punch
- Mold / Mould
- Fastener
- Stamped part
- Hand tools
  
  You can purchase multiple categories from us, reducing your sourcing cost and time.
1. Proven Market Recognition
  
  Our markets cover:
- Domestic Market: 50%
- Southeast Asia: 13%
- Mid East: 10%
  
  Stable sales in domestic and overseas markets prove our product quality, price competitiveness and after-sales service are widely recognized.
1. Geographic Advantage: Zhejiang, China
  
  Located in Zhejiang, close to Ningbo Port — one of China’s biggest ports. We have convenient logistics, short delivery time and lower shipping cost, which greatly improves your supply chain efficiency.