How to develop clear machining process requirements? A must-see communication checklist for designers and purchasing

Avoid processing ambiguity and rework! This article provides designers and purchasers with a complete copy of theList of machining process requirementsWe cover key items such as materials, tolerances, heat treatments, surface treatments, etc. to ensure that your needs are accurately understood and realised.

Develop machining process requirements: communicate accurately and do it right the first time

INTRODUCTION: “Many machining problems stem from unclear requirements. Providing a clear document of process requirements is the first step to a successful project.”

I. What should a complete list of process requirements contain?

(presented in a list or table)

Basic information: part number, name, version.

Material Requirements: Brand, specification, standard number (e.g. 6061-T6 aluminium bar, in accordance with GB/T 3191).

Dimensional and geometrical requirements: references to tolerance standards (e.g. ISO 2768-m), special tolerances for critical dimensions, form and position tolerances.

Surface treatment requirements: surface roughness (e.g. Ra 1.6), plating (e.g. hard chrome plating, thickness 10-15μm), anodising (colour, film thickness), sandblasting, etc.

Heat treatment requirements: tempering HRC28-32, carburising quenching, etc.

Other special requirements: burr removal standards, cleanliness, packaging, labelling.

Second, how to effectively communicate your requirements with the machine shop?

(3D model (STEP format) + 2D drawing (PDF/DWG) + process requirement document (PDF) recommended)

III. Examples of processing problems caused by common “unclear requirements”

(Case 1: Only “smooth surface” was written, leading to inconsistent understanding of roughness. Case 2: Heat treatment was not specified and the part was subsequently deformed.)

Conclusion & CTA: Clear requirements are the beginning of co-operation. In order to ensure that these requirements are strictly enforced in production, a professional machine shop must follow a rigorous set of machining process specification requirements (link to article V).

FAQ.

“What is the visual difference between surface roughness Ra 3.2 and 1.6?” (Answer: A comparison picture is attached, Ra 1.6 is obviously smoother, and Ra 3.2 shows minor machining marks.)

“When is it necessary to specify the standard number of a material?” (Answer: For critical performance parts, designation is highly recommended to ensure consistency of material composition and performance.)