- Burrs and sharp edges: out-of-control cutting/stamping process
- Problem manifestation:
There are uncleaned metal burrs and sharp edges on the edges or holes of accessories.
- Reasons for improper processing:
o Wear of mold edges and excessive gaps
o Wrong stamping speed/pressure parameters
o Lack of deburring process
- Serious consequences:
o Cutting users or scratching leather/clothing
o Burrs fall off and get stuck in zippers or mechanical structures
o Electroplating is prone to accumulation or falling off at burrs
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- Deformation and warping: Improper stress release or clamping
- Problem manifestation:
The buckle is not round, the buckle is not flat, and the rivet base is crooked.
- Reasons for improper processing:
o No stress relief annealing after stamping/bending
o Unreasonable fixture design leads to excessive local stress
o Excessive feed rate during cutting of thin-walled parts causes thermal deformation
- Serious consequences:
o Difficult assembly
o Easy to break when stressed
o More obvious deformation after electroplating, uneven gloss
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- Thread slippage or cracking: Tapping process defects
- Problem manifestation:
The screw slips when screwed in and the thread crest breaks.
- Reasons for improper processing:
o Wrong bottom hole diameter before tapping
o Tap wear and failure to replace leads to poor cutting
o Brass chips block the tooth socket and are not cleaned
- Serious consequences:
o Loss of accessory functionality (such as inability to fix handles or shoulder straps)
o High rework cost
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- Blistering/peeling of electroplating layer: Pretreatment lays the root of the problem
- Problem manifestation:
The surface of the plating layer bulges and peels off in pieces, exposing the base brass.
- Root causes of improper processing:
o Residual cutting fluid/polishing paste is not completely removed after machining
o Excessive pickling leads to surface intergranular corrosion
o Insufficient activation, substrate surface passivation
- Serious consequences:
o “Skin bursting” occurs within 24 hours – batch scrapping
o Corrosion spreads from under the coating, accelerating the rusting of accessories
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- Microcracks and hidden damage: rough processing
- Problem manifestation:
Fine cracks that are difficult to detect with the naked eye are mostly at the bend or hole edge.
- Causes of improper processing:
o The die radius is too small during stamping, causing material tearing
o The bending angle is too large and exceeds the material extension limit
o Hard brass is not annealed when stamped at low temperature
- Serious consequences:
o Sudden fracture during use
o The crack becomes a corrosion channel, which cannot be compensated by electroplating
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- Size deviation: lax process discipline
- Problem manifestation:
Accessory aperture is too large, buckle gap is too large, and chain link length is inconsistent.
- Reasons for improper processing:
o Tool wear is not compensated in time
o Fixture positioning is not used, manual operation errors accumulate
o Temperature changes lead to inaccurate measuring tools
- Serious consequences:
o Looseness and abnormal noise after assembly
o Functional failure
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Key to prevention: Eliminate the problem before electroplating
Lessons learned from blood and tears: Electroplating will magnify all defects of the substrate! A 0.1mm burr may become a visible bump after electroplating, and a hidden crack may expand into a through seam after electroplating. Investing in process accuracy before electroplating is more cost-effective than full inspection after electroplating.
Industry consensus: 60% of quality problems of accessories are caused by pre-processing, 30% are attributed to pre-treatment, and only 10% are due to errors in electroplating itself. Only by controlling the details of machining can the great quality of small accessories be achieved.
