Company Response to Wear-Resistant Steel Hardness Complaint

On July 16th, we received a complaint from XXXXXX Company regarding the wear-resistant steel we supplied. The customer claimed the material did not meet the required hardness standards, as they found the gray-black sample (taken from our bulk goods) could be easily drilled through, whereas the rust-colored sample marked “ZGT-NM500” could not be penetrated by drilling.

Based on this comparison, the customer concluded that the bulk material’s hardness was significantly lower than the test sample’s, and therefore the supplied goods were either non-compliant with quality requirements or indicated possible fraudulent activity.

Internal Quality Inspection Report

We promptly conducted an inspection of the production process for this batch of goods and confirmed standard operations throughout. Our findings are as follows:

1. Our material warehouse exclusively stores wear-resistant steel plates, with no ordinary steel plates present, eliminating any possibility of material mix-up.

2. Given the customer’s particular emphasis on this order, we conducted individual hardness tests and maintained complete records prior to cutting. Processing only commenced after all materials passed inspection. (Supporting test documentation is available)

3. During final shipment inspection, Mr. Xia personally conducted random hardness tests on selected materials, all of which met specifications.

Based on this comprehensive review, we confirm the materials fully comply with quality requirements.

Analysis of Customer’s Claim

Situation Overview

The customer provided a video as evidence of alleged material defects, demonstrating the following:

– (Drillable) – The bulk sample was successfully drilled through during testing.
– (Non-drillable) – The previously provided reference sample resisted drilling under the same conditions.

Based on this comparison, the customer concluded that:
1. The drillable workpiece had significantly lower hardness than the non-drillable sample.
2. The supplier may have engaged in fraudulent material substitution.

Technical Assessment

Drillability of Wear-Resistant Steel
The customer’s assumption that drillable wear-resistant steel is non-compliant requires clarification. While wear-resistant steel possesses high hardness, drilling remains possible with appropriate tool selection. Our technical experience indicates:
– Larger hardness differentials between drill bit and material facilitate easier drilling and extend bit lifespan.
– Smaller hardness differentials increase drilling difficulty, potentially preventing penetration entirely.

Testing Methodology Considerations
The observed discrepancy (drillable bulk sample vs. non-drillable reference sample) may stem from testing variables rather than material inconsistency. Our historical data shows similar cases where:
– Initial samples were drillable while subsequent samples resisted drilling.

– This typically occurred when:
1. No cooling was applied during initial drilling, causing bit annealing from frictional heat.
2. The annealed bit then failed to penetrate subsequent samples.

The customer’s video aligns with this scenario, showing:
1. Successful drilling of the first sample but failure on the second.
2. Absence of cooling measures during testing.

Conclusion
The observed results likely reflect bit performance degradation during testing rather than material non-conformance. The initial drilling operation may have compromised the bit’s hardness, preventing penetration of subsequent samples.

If our assessment regarding drill bit degradation is accurate, the used drill bit should no longer penetrate the material. We recommend conducting an additional drilling test on the same plate to verify this hypothesis.

Third-Party Hardness Verification

To ensure objective results, we suggest performing standardized hardness testing at an accredited testing facility.

Conclusion

We value our partnership with your company and stand firmly behind our products. We solemnly affirm that all supplied materials are genuine and meet all specified quality standards.