Introduction
The U.S. brake components market is once again under close regulatory scrutiny. In November 2025, the U.S. Department of Commerce formally initiated a country-wide anti-circumvention inquiry to determine whether certain Chinese compacted graphite iron (CGI) brake drums are being imported into the United States in a way that sidesteps existing antidumping (AD) and countervailing duty (CVD) orders on brake drums from China .
The inquiry, requested by Webb Wheel Products, Inc., has significant implications for importers, distributors, and aftermarket suppliers – particularly those sourcing heavy-duty brake drums from China.
Background: The Existing AD/CVD Orders
In August 2025, Commerce imposed AD and CVD orders on certain gray cast iron brake drums from China (and Türkiye), following findings that unfairly priced and subsidized imports were materially injuring U.S. producers.
The orders apply to brake drums meeting specific dimensional and weight criteria – generally large, heavy-duty drums used on Class 7 and 8 trucks and trailers – and they carry steep cash deposit rates for Chinese exporters, including China-wide rates exceeding 150 percent in some cases.
The scope of these orders is intentionally broad. It covers finished and unfinished brake drums, as well as drums imported as part of assemblies (such as drum-hub assemblies). What it does not explicitly name is brake drums made from CGI rather than gray cast iron.
>>> Read more: U.S. Finalizes CVD Orders on Brake Drums from China and Turkey
Why CGI Brake Drums Are Under Scrutiny
According to the filing, Webb began hearing in mid-2025 that low-priced Chinese brake drums were entering the U.S. market and being marketed as “non-gray iron” products, despite having the same size, function, and end use as in-scope brake drums.
CGI, or compacted graphite iron (also referred to as vermicular iron), is not a new material, but its use in heavy-duty brake drums appears to have emerged only after the AD/CVD investigations were underway. From a technical standpoint:
- CGI and gray iron brake drums are visually indistinguishable.
- The chemical difference between the two materials is minimal (less than 1% of total inputs).
- Both are manufactured using essentially the same production process and equipment.
- Performance testing shows CGI drums meet the same FMVSS 121 braking standards and perform within the same range as comparable gray iron drums .
In other words, from the perspective of fleet operators and aftermarket buyers, CGI brake drums function as direct substitutes for gray iron brake drums.
The Product In Focus: M328D557 Brake Drum
Commerce’s notice explicitly references model M328D557, produced by PanAsia CVD (HK) Limited, as an example of the merchandise under review. Evidence submitted to Commerce indicates that:
- The drum is produced in China and stamped “Made in China.”
- It matches the size and weight specifications of in-scope brake drums (approximately 16.5” × 7”, over 50 pounds).
- It is sold in the U.S. aftermarket under private-label brands, without being identified as CGI in marketing materials.
- Metallurgical testing confirmed the drum is made of compacted graphite iron.
The filing also alleges that multiple exporters and distributors may be involved, reinforcing Webb’s request for a country-wide inquiry, rather than one limited to a single producer.
How Commerce Will Assess Circumvention and Potential Outcomes
Under U.S. trade law, Commerce has authority to extend AD/CVD orders to later-developed merchandise – products that did not exist commercially at the time of the original investigation but are essentially the same as covered products.
In this inquiry, Commerce will assess factors such as commercial availability, physical characteristics, end use, customer expectations, marketing practices, and channels of trade. The filing argues that CGI brake drums offer no additional functionality and were introduced to exploit a perceived gap in the scope language.
If Commerce determines that CGI brake drums constitute circumvention of the existing orders, it could:
- Expand the scope of the AD/CVD orders to explicitly include CGI brake drums.
- Direct U.S. Customs and Border Protection to collect cash deposits on past and future imports of the affected merchandise.
- Apply those requirements on a country-wide basis, impacting all Chinese exporters of similar CGI brake drums.
For importers and distributors, this creates real commercial risk. Products currently being entered as “non-gray iron” brake drums could suddenly face substantial duty liability, potentially retroactive. Supply chains built around low-cost CGI drums may need to be reassessed quickly.
TBP Auto’s Commitment to Compliance and Supply Chain Integrity
As the Department of Commerce’s inquiry moves forward, one message is clear for the aftermarket: trade compliance and supply chain transparency matter more than ever. Regulatory scrutiny in the brake components sector is increasing, and businesses that proactively manage sourcing risk will be best positioned to navigate potential disruptions.
At TBP Auto, we take these developments seriously. We are committed to working with trusted manufacturing partners, maintaining full visibility into our supply chain, and aligning our product offerings with applicable U.S. trade laws and regulations.
Our focus remains on delivering high-quality brake components that meet industry standards while supporting a fair, stable, and compliant aftermarket.
We will continue to monitor this investigation closely and share relevant updates as they become available. For customers and partners with questions about sourcing, specifications, or regulatory developments, TBP Auto remains a reliable resource in an evolving trade environment.
For more information regarding the circumvention inquiry, reference the official notice by the International Trade Administration here.
