Lower middle market private equity firm
Rock Gate Partners
- HeadquartersChicago, IL S5
- Founded2006 S5
- Websiterockgatepartners.com
- Last verifiedOctober 28, 2026
At a glance
| EBITDA range | $3M to $15M S1 |
|---|---|
| Revenue range | $10M to $125M S1 |
| Check size | $3M to $50M S1 |
| Deal types | Platform, Add-on, Growth, Minority S1 |
| Geography | United States, Canada S1 |
| Sectors | Industrial & Manufacturing, Distribution |
What Rock Gate Partners buys
Rock Gate Partners is a Chicago private equity firm, founded in 2006, that buys control of niche market leaders in the lower middle market. It looks for companies with $10 million to $125 million of sales and $3 million to $15 million of EBITDA at margins above 10 percent, valued at $10 million to $100 million, and it invests $3 million to $50 million of equity. Deal types include recapitalizations, buyouts, corporate divestitures, industry roll-ups and add-ons, and it will sometimes provide later-stage growth capital. Companies need to operate mainly in the U.S. or Canada.
The firm calls itself a generalist but spends most of its time on engineered industrial products, manufacturing, specialized business services, value-added distribution, infrastructure, specialty food and agriculture, and physical and electronic security. It invests money from its principals, advisors and wealthy partners rather than a fixed-life fund. Its two current platforms, H3 Manufacturing Group and Perimeter Security Partners, both plan to grow through acquisitions.
Recent deals
Announced in the 24 months before October 28, 2026.
| Date | Company | Type | Sector | Source |
|---|---|---|---|---|
| Sep 2025 | Shore Systems and Shore Technology GroupLong Island CCTV and access control installer added to Perimeter Security Partners; founder stays as president and became an equity partner. Closed August 27, 2025 | Add-on | Source | |
| Jun 2025 | RFR Metal FabricationOxford, North Carolina precision metal fabricator added to H3 Manufacturing Group; its manager stays to lead it | Add-on | Industrial & Manufacturing | Source |
| Feb 2025 | H3 Manufacturing GroupAnnouncement of the June 2024 recapitalization of the Champaign, Illinois contract manufacturer, done with management and Ironwood Capital | Platform | Industrial & Manufacturing | Source |
Portfolio by sector
From the firm's portfolio page S3.
Minority Investments
- GLS Capital Minority holding
- Intensity Therapeutics Minority holding
- Novus Law Minority holding
- NRG Minority holding
- OhmEV Minority holding
- Purple Arch Ventures Minority holding
- Solarcore Minority holding
- Triangle Square Condominium Minority holding
- CA6 Minority holding
- Portico Minority holding
Platform Investments
- H3 Manufacturing Group
- Perimeter Security Partners
Past investments: Whitewater Brands, Walpar
Greymont’s take
How Rock Gate Partners fits a seller
Rock Gate suits owners of a well-regarded niche manufacturer, distributor or security business who want a long-term partner rather than a buyer working to a fund deadline. Because it invests its principals' and partners' own money, it says it does not plan holding periods around fund cycles, and its past holds were long: about nine years for Walpar and about ten for Whitewater Brands. Founders often stay and keep a stake. In 2025 Shore Systems' founder remained president and became an equity partner in Perimeter Security Partners, and RFR Metal Fabrication's manager stayed on to lead that business.
With only two current platforms, Rock Gate does few deals a year. Owners should ask how much equity it can commit on its own and whether co-investors, such as Ironwood Capital in the H3 deal, would be part of the capital structure.
Questions owners ask
What size company does Rock Gate Partners buy?
Its criteria call for $10 million to $125 million of sales and $3 million to $15 million of EBITDA with margins above 10 percent. Deals are usually control transactions valued at $10 million to $100 million, using $3 million to $50 million of equity.
Does Rock Gate invest from a traditional fund?
No. It says it invests capital from its principals, advisors and high net worth partners, and that it does not manage holding periods around fund cycles, which allows it to own companies for longer.
Is Rock Gate buying add-ons right now?
Yes. Perimeter Security Partners bought Long Island security installer Shore Systems in August 2025 and says it is looking for more deals, and H3 Manufacturing Group added RFR Metal Fabrication of Oxford, North Carolina in 2025.
Sources
- S1Rock Gate Partners: Investment Criteria, Industry Sectors and Investment Types Accessed October 28, 2026
- S2Rock Gate Partners: Why Rock Gate Accessed October 28, 2026
- S3Rock Gate Partners: Investments Accessed October 28, 2026
- S4Rock Gate Partners: News Accessed October 28, 2026
- S5Perimeter Security Partners Acquires Shore Systems and Shore Technology Group (September 25, 2025) Accessed October 28, 2026
- S6H3 Manufacturing Group Recapitalization (February 27, 2025) Accessed October 28, 2026
Compiled by Greymont Advisors from public sources, including the firm’s own website and press releases. Greymont is not affiliated with Rock Gate Partners. Figures are as reported on the dates shown and may have changed. Request a correction