Conversion to Ductile Iron Saves Over 30%

AFS Corporate Member Lethbridge Iron Works (Lethbridge, Alberta, Canada) was tasked with converting a six-piece steel fabrication that incorporated two cast bolt-on attachments into an all-in-one ductile iron main frame casting for an agricultural customer.

The finished product was cast in ASTM A536 Grade 65-45-12, produced via horizontal green sand molding, robotically ground and CNC machined. It weighs 68 lbs., and connects all components (disk wheel, seed boot, depth adjuster, packer wheels) to the toolbar of an agricultural seeding disk/hoe opener.

The customer needed greater torsional strength from the component in order to reduce the flex that occurs when stresses are placed on the opener during cornering in the field. In addition to the part’s performance, there was a need to reduce the workload on the plasma laser cell that produced the fabrication’s components and a desire to reduce the bill of material required to make each part.  Ultimately, the customer wanted a better part at a reduced overall cost both internally and externally to the end user.

Through collaboration with Lethbridge Iron, a design for castability, and also for economic manufacturability, addressed and overcame the challenge of redesigning the original part’s length to allow for a multi-impression pattern achieved a design that incorporated features previously achieved only by fastening separate castings to the fabrication.  

The steel fabrication to casting conversion achieved an overall part cost savings of more than 30%, resulted in a capital expenditure savings from not having to purchase an additional laser cutter, reduced the bill of materials, reduced labor costs and the reliance on employee attendance for production.  

“It was a tremendous win,” said Mark Mundell, Lethbridge Iron Works’ director of sales.

Click here to see this story as it appears in the July/August 2019 issue of MCDP.