What are the specific requirements for the processing accuracy of metal stamping parts?

Your question is particularly critical! The machining accuracy of metal stamping parts directly determines the assembly adaptability and performance of products. The core requirements focus on three dimensions: dimensional tolerance, shape and position tolerance and surface quality, and the specific standards of different application scenarios are significantly different.

First, the core accuracy requirements and specific standards

1. Dimensional tolerance accuracy (the most basic core requirement)

Key indicators: The deviation range between the actual size and the design size of the parts shall conform to GB/T 13914-2002 standard for dimensional tolerance of stamping parts.

Specific requirements:

Ordinary hardware (such as furniture hardware, daily tool accessories): the dimensional tolerance level is mostly IT12-IT14, such as a round hole with a diameter of ≤50mm, and the tolerance range is 0.15-0.3 mm.

Precision electronic hardware (such as connector terminals and sensor shrapnel): the tolerance level reaches IT8-IT10, and the tolerance of tiny dimensions (such as pin width ≤5mm) can be controlled within 0.01-0.03 mm..

High-end mechanical parts (such as automobile stamping parts and aviation hardware): the tolerance level of key dimensions shall be ≥IT7, for example, the tolerance of engine connecting rod hole shall be ≤±0.005mm to ensure assembly accuracy.

2. Form and position tolerance accuracy (to ensure the stability of assembly and use)

Key indicators: deviation of geometric shape and relative position of parts, including flatness, parallelism, verticality, coaxiality, etc.

Specific requirements:

Flatness: the flatness of common plate stamping parts (such as gaskets and cover plates) is ≤ 0.2 mm/100mm; The flatness of precision guides (such as slide blocks) shall be ≤0.03mm/100mm to avoid assembly jamming.

Parallelism/verticality: For stamping parts used in pairs (such as bolt holes and locating pins), the parallelism tolerance is ≤0.05mm, and the verticality tolerance is ≤0.02mm, so as to ensure the assembly fit without gaps.

Coaxiality: with stepped holes or shaft stamping parts (such as gear blanks and bearing seats), the coaxiality tolerance is ≤0.015mm to prevent eccentric jitter during rotation.

3. Surface quality accuracy (affecting appearance and functional reliability)

Key indicators: surface roughness, defects (scratches, burrs, indentations) and flatness.

Specific requirements:

Surface roughness: Ra of common hardware ≤ 1.6μ m; Precision electronic components (such as conductive terminals) Ra≤0.8μm, reducing contact resistance; Appearance parts (such as household appliance shell stamping parts) Ra≤0.4μm, ensuring smooth and flawless surface.

Burr control: the burr height of ordinary parts is ≤ 0.1 mm; The burr height of precision parts (such as battery pole pieces and micro gears) shall be ≤0.01mm to avoid scratching the assembly surface or affecting the electrical conductivity.

Surface defects: cracks, delamination, scale and other defects are not allowed; Appearance parts are not allowed to have obvious scratches (length ≤0.5mm) and indentations (depth ≤0.02mm).

Second, the special scene additional accuracy requirements

Elastic stamping parts (such as springs and buckles): the springback accuracy should be controlled, and the springback deviation should be ≤0.02mm to ensure the stability of elastic tension after assembly.

Welding stamping parts: the clearance tolerance of overlapping edge is ≤0.1mm, so as to avoid virtual welding and missing welding; The flatness of the welding surface is ≤0.05mm to ensure the welding strength.

Plated stamping parts: The surface after stamping should be free of oil stains and burrs, so as to avoid affecting the adhesion of the coating. After plating, the dimension tolerance should be reserved with a coating thickness of 0.005-0.01 mm..

Third, the key premise of precision guarantee

Die accuracy is the core: the dimensional tolerance of die parts should be 2-3 grades higher than that of workpieces, and the uniformity of die gap should be controlled at 0.01-0.03mm to avoid deformation of parts during stamping.

Equipment stability: High-speed precision punch (positioning accuracy ≤0.002mm) should be selected for precision stamping, and automatic feeding device (feeding accuracy ≤±0.01mm) should be used to reduce human error.