Zinc Casting Alloy Ingot for Sheet Metal Forming Dies and Plastic Injection Molds

B793: Standard Specification for Zinc Casting Alloy Ingot for Sheet Metal Forming Dies and Plastic Injection Molds

In the demanding world of manufacturing, the precision and durability of tooling are paramount. For engineers and designers involved in creating sheet metal forming dies and plastic injection molds, the integrity of the raw material directly impacts the performance and longevity of their finished products. ASTM B793 provides an essential, industry-leading standard that ensures the quality and composition of zinc casting alloy ingots, offering a proven foundation for critical tooling applications.

What is B793?

ASTM B793 is an authoritative standard specifying the requirements for zinc casting alloy ingots intended for remelting and subsequent use in the fabrication of dies for sheet metal forming and molds for plastic injection. Developed by ASTM Committee B02 on Nonferrous Metals and Alloys, its primary purpose is to guarantee a consistent and reliable supply of high-quality zinc alloys that meet stringent performance criteria for these specialized tooling applications.

Scope & Purpose

This comprehensive standard governs the chemical composition and material quality of zinc alloy ingots designated for the production of sand cast or plaster cast dies and molds. It specifically covers two distinct alloys, Alloy A and Alloy B (commonly known as Kirksite A and Kirksite B), detailing their UNS designations and performance characteristics for applications like drop hammer and hydraulic sheet metal stamping dies, as well as plastic injection molds. The specification focuses on the ingot form itself and does not extend to the manufacturing processes of the final dies or molds, nor does it cover safety protocols for material handling.

Who Must Comply?

• • Primary audience: Materials Engineers, Metallurgists, Manufacturing Engineers, Tool and Die Makers, and Process Engineers.
• • Industries affected: Automotive, Aerospace, Plastics Manufacturing, Metal Fabrication, and General Manufacturing.
• • Compliance nature: Voluntary, but highly recommended for ensuring product quality and performance in critical tooling applications.
• • Enforcement: Compliance is typically verified through supplier certifications, material testing, and internal quality control processes within manufacturing organizations.

Key Requirements Overview

The standard requires that zinc alloy ingots conform to precise chemical composition limits, as detailed in its tables, ensuring predictable metallurgical properties. Professionals must ensure that the supplied ingots are free from dross, slag, and other detrimental contaminants that could compromise the integrity of cast tooling. Key provisions include adherence to specified ingot configurations and the use of approved methods for chemical analysis to verify composition. Furthermore, the standard references other ASTM standards for general requirements, sampling, and marking, promoting a unified approach to material quality.

Related Standards & References

ASTM B793 works in conjunction with several complementary standards. ASTM B949, Specification for General Requirements for Zinc and Zinc Alloy Products, provides overarching requirements applicable to zinc and zinc alloy products, including those covered by B793. ASTM B897, Specification for Configuration of Zinc and Zinc Alloy Jumbo, Block, Half Block, and Slab Ingot, defines acceptable ingot shapes and sizes. Additionally, ASTM B908, Practice for the Use of Color Codes for Zinc Casting Alloy Ingot, aids in material identification through standardized color coding, ensuring proper material selection.