IP Law Daily, TRADE SECRETS—E.D. Wis.: Preliminary injunction denied in fastener maker’s trade secrets lawsuit against former employee, (Dec 11, 2025)

By Saurabh Kashyap, B.A., M.A., LL.B., LL.M.

The fastener and wire management company failed to demonstrate irreparable harm or trade secret misuse to justify injunctive relief.

The federal district court in Milwaukee, Wisconsin, denied Penn Engineering & Manufacturing Corp.'s motion for a preliminary injunction against former employee Thomas Marsden and his new employer, HellermannTyton Corp. The court found that the plaintiffs failed to establish a likelihood of irreparable harm or success on the merits of their claims under the Defend Trade Secrets Act (DTSA), the Wisconsin Uniform Trade Secrets Act (WUTSA), and the Pennsylvania Uniform Trade Secrets Act (PUTSA). The court acknowledged a likely breach of a confidentiality clause by Marsden but found that it did not merit equitable relief. A request for attorney fees by the defendants was also denied (Penn Engineering & Manufacturing Corp. v. Marsden, No. 2:25-cv-00467-BHL (E.D. Wis. Dec. 9, 2025)).

Background. Penn Engineering, along with its subsidiary Heyco, designs and manufactures mechanically attached fasteners and wire management solutions for various industries, including automotive, consumer electronics, and solar energy. HellermannTyton Corp., also operating in the wire and solar sectors, manufactures plastic components for utility-scale solar farms. Thomas Marsden worked for Heyco for over nine years, ultimately serving as Director of Product Marketing and Renewable Energies. In February 2025, Marsden accepted a position at HellermannTyton.

The plaintiffs identified the alleged trade secrets as sales lead databases, project files exported from SharePoint, and internal training materials. Marsden had forwarded these documents to his personal email in the days leading up to and including his final day at Heyco. Penn Engineering contended that these materials held commercial value and were protected under trade secret laws.

After learning of the data transfers, Heyco terminated Marsden's employment on February 18, 2025, the day he disclosed his resignation. An internal review revealed that Marsden had exported and emailed company files, including client leads and financial training materials. Penn Engineering accused Marsden of misappropriation. Marsden responded by deleting the documents and producing a video showing their removal, although this act contravened Penn Engineering’s directive to preserve them.

Marsden began working at HellermannTyton on March 5, 2025. HellermannTyton conducted its own internal and third-party forensic review of Marsden’s company laptop, which found no evidence that Heyco’s information had been accessed, transferred, or stored. Penn and Heyco filed suit in the Eastern District of Wisconsin, seeking injunctive relief. The court permitted expedited discovery and held an evidentiary hearing in July 2025.

Preliminary injunction analysis. To obtain a preliminary injunction, plaintiffs must satisfy the four-part test set out in Winter v. Natural Resources Defense Council, Inc., 555 U.S. 7, 20 (2008), demonstrating: (1) a likelihood of success on the merits; (2) irreparable harm absent relief; (3) a balance of hardships in their favor; and (4) that the injunction is in the public interest.

Trade secrets claims. The district court found that the plaintiffs failed to meet the threshold showing for trade secret misappropriation. The court assumed, for the motion, that the documents constituted trade secrets, but concluded that the plaintiffs failed to show that Marsden obtained or used them by “improper means” as defined under the DTSA, 18 U.S.C. § 1839(6).

The court distinguished the plaintiffs’ case from In re Adegoke, 632 B.R. 154 (Bankr. N.D. Ill. 2021), where evidence of pretextual access, lack of credible explanation, and destruction of evidence supported a finding of misappropriation. Unlike Adegoke, Marsden provided consistent testimony that he accessed the files to perform his job responsibilities at Heyco, including creating Google-based “lead maps,” and that his actions, while in violation of IT policy, were not done with improper intent. The court found his testimony credible and corroborated by evidence of routine practices within the sales team.

HellermannTyton, for its part, had conducted an internal and independent forensic investigation that yielded no evidence of misappropriation. The court held that mere speculation that Marsden might retain knowledge or access to information was insufficient. Penn Engineering and Heyco, thus, failed to show a likelihood of success under the DTSA, WUTSA, or PUTSA.

Tortious interference. Plaintiffs also argued that HellermannTyton tortiously interfered with the confidentiality agreement between Marsden and Heyco. To prevail under Wisconsin law, plaintiffs had to prove intentional interference without justification that caused a breach and damages. However, the court found no evidence of interference. HellermannTyton asked Marsden about contractual obligations and explicitly instructed him not to share confidential information. The alleged interference occurred after the purported breach, and plaintiffs provided no evidence that HellermannTyton encouraged or benefited from the breach. Accordingly, the claim for tortious interference was not likely to succeed.

Breach of contract. The court held that the plaintiffs were likely to succeed on the claim that Marsden breached Paragraph 4 of his confidentiality agreement, which required the return of company property upon termination. Marsden admitted to retaining some files after his employment, although he deleted them shortly afterward. While the court found a strong likelihood of a technical breach, it noted that the plaintiffs failed to provide any evidence of resulting harm. No customer loss or business damage was identified.

Irreparable harm. The plaintiffs argued that a presumption of irreparable harm applies in trade secret cases. The court rejected this argument, citing Life Spine, Inc. v. Aegis Spine, Inc., 8 F.4th 531, 545 (7th Cir. 2021), which reaffirmed that courts must make an independent finding of irreparable harm. The plaintiffs also relied on a clause in the confidentiality agreement asserting that breaches would cause irreparable harm. The court found such clauses non-dispositive, citing Baker’s Aid v. Hussmann Foodservice Co., 830 F.2d 13, 16 (2d Cir. 1987).

The court further noted that mere speculative fears of misuse were insufficient. With no evidence that Marsden retained any files or shared them with HellermannTyton, the plaintiffs failed to show they faced harm that damages could not remedy.

Attorney fees. The defendants sought attorney fees under federal and state trade secrets statutes, which allow fee-shifting in cases brought in bad faith. The court denied the request, finding that although the plaintiffs did not prevail, they had a reasonable basis to bring the motion given the timing and nature of Marsden’s conduct.

The Case is No. 2:25-cv-00467-BHL.

Judge: Ludwig, B.

Attorneys: Suzanne M. Watson (Ogletree Deakins Nash Smoak & Stewart PC) for Penn Engineering & Manufacturing Corp. and Heyco Products Corp. Sally A. Piefer (Lindner & Marsack SC) for Thomas Marsden. Benjamin C. Bauman (Buelow Vetter Buikema Olsen & Vliet LLC) for Hellermanntyton Corp.

Companies: Penn Engineering & Manufacturing Corp.; Heyco Products Corp.; Hellermanntyton Corp.

Cases: TradeSecrets WisconsinNews