Malleable Cast Iron Fastener

Malleable Cast Iron Fastener-Technical Overview

1.Product Definition

A Malleable Cast Iron Fastener is a high-strength scaffolding connector manufactured through specialized heat treatment of white cast iron,transforming its microstructure into tempered graphite for enhanced ductility and impact resistance.Primarily used in formwork systems and tube-and-coupler scaffolding,it bridges the performance gap between brittle cast iron and forged steel fasteners.

2.Key Advantages

Property Technical Benefit

Ductility 12-18%elongation(vs 3-5%in gray iron)–withstands dynamic loads without cracking

Tensile Strength 350-550 MPa(Grade KT350-10 per GB/T 9440)

Corrosion Resistance Phosphating/zinc plating options(salt spray test>500h)

Clamping Force 10.5kN minimum(exceeds EN 74-1 standard)

3.Manufacturing Process

Casting:White iron poured in sand molds

Annealing:900°C×30h+staged cooling to form temper carbon

Machining:CNC-turned contact surfaces(Ra≤6.3μm)

Surface Treatment:Electrophoretic coating(20-40μm)

4.Comparative Analysis

Parameter Malleable Iron Ductile Iron Gray Iron

Yield Strength 250MPa 400MPa N/A(brittle)

Cost Index 1.0x 1.8x 0.7x

Impact Absorption 25J(Charpy)60J 2J

5.Scaffolding Applications

Critical Load Zones:Node connectors in shoring towers

High-Vibration Areas:Bridge construction formwork

Corrosive Environments:Coastal projects(with zinc plating)

6.Quality Standards

Mechanical:EN 1562(EN-GJMW-350-10)

Dimensional:BS 1139-2.2

Safety:OSHA 1926.452(a)(1)

*Note:Not recommended for temperatures below-20°C due to reduced impact toughness.For Arctic conditions,consider forged steel alternatives.*

This engineered fastener combines cast iron's economies with near-steel performance,making it ideal for contractors balancing budget and structural requirements in medium-duty applications.