The global iron casting market size was valued at USD $101.17 billion in 2021.* Cast iron is used around the world in brake discs, chains, machinery, cookware, shafts and rods, housings, mining equipment, etc. We’ll look at several applications of Lean and Six Sigma in cast iron manufacturing and finish with a video of mostly manual cast iron production.
*Source

In a paper title “A Proposed Supply Chain Model for Productivity Enhancement in Medium Scale Foundry Industries” authors S. Nallusamy, A.M. Muhammad Umarmukdhar, and R. Suganthini Rekha discuss their research to investigate the defects in cast iron foundries and propose remedies and a supply chain model.
The paper includes:

  • Foundry Processes and Equipment
  • Foundry Processes Map
  • Casting Defects
  • Quality Tools Flow Chart
  • Rejection Data Sheet
  • Inter Department Relationship Analysis for Sand Inclusion Defect
  • Fishbone Diagram for Sand Inclusion
  • Inter Department Relationship Analysis for Sand Inclusion Defect
  • Overall Percentage of Rejections by Adding Air Vents (Before & After)
  • Parameter Wise Percentage of Rejection by Adding Air Vents (Before & After)

Click on the following link into your browser to access the paper.

Six Sigma Implementation in Metal Casting Production
In a case study titled “Implementation of Six Sigma Approach in Quality Control of Metal Casting
Products Made From Gray Cast Iron Type Fc 250: A Case Study In Small and Medium Enterprises In
Indonesia” authors Petir Papilo and others discuss the implementation of Six Sigma steps in order to
control product quality.
The case study includes:

  • Percentage of Product Defects
  • Stages of Making Sand Molds
  • Five Dominant Product Defect Types
  • Product Defects Histogram
  • Metal Casting Process Diagram
  • Pareto Diagram of Product Defects
  • Fishbone Diagram for Porous and Shifted Core
  • Diagram of Cause and Effect Relationships of Product Defects
  • Product Defects Repair Plan Steps
  • Control Mechanisms

You can read the case study here.

Applying Six Sigma Method and Taguchi Technique to Reduce Cast Iron Shrinkage Defect
In a paper titled “Analysis of Shrinkage Defect in Sand Casting by Using Six Sigma Method with Taguchi Technique” authors M.A. Omprakas and others discuss the use of the Six Sigma method and a Taguchi experiment to reduce the shrinkage defect which occurs in the external bearing ring of ductile cast iron which is produced in the leading casting industry in Coimbatore.

The paper includes:

  • Casting Iron Industry Product Data: Rejection Data
  • Products with Different Kinds of Defects
  • Cause and Effect Diagram for Shrinkage Defect
  • Taguchi Experiment Design and Analysis

You can read the paper here

Reducing Casting Costs Through the Application of Lean Principles
In an article titled “How to Apply Lean Principles to Reduce Casting Costs” author Emily Newton
discusses proactive ways to use Lean manufacturing to keep expenses down in a foundry.

  • Encourage All Employees to Take Ownership
  • Use Process Mapping to Identify Bottlenecks
  • Group Manufacturing Cells by Product
  • Develop a Strategic Approach to Minimize Waste
  • View Lean Implementation as a Journey

You can read the article here.

A Literature Review of Process Knowledge for Quality Improvement in Sand Casting
In a short paper titled “Process knowledge for improving quality in sand casting foundries: A literature review” authors Cindy Sithole, Kasongo Nyembwe and Peter Olubambi present a literature review on process knowledge in manufacturing focusing in sand casting method specifically for the metal casting industry.

The authors relate process knowledge for Six Sigma applied to sand casting method in order to reduce
process variation and improve quality of castings. You can read the paper here.

Cast Iron Manufacturing by Mostly Manual Methods
See the manual methods in cast iron manufacturing in this video from Project 03.
You can watch the video here.