What STEMCO makes

STEMCO manufactures wheel-end and steering components for heavy-duty commercial vehicles: wheel seals, hub caps, bearings, pre-adjusted hub assemblies, axle fasteners, and king pins. The company describes itself as the No. 1 U.S. manufacturer of wheel-end seals for heavy-duty trucks and trailers. Its product families span truck, trailer, heavy haul, agriculture, refuse, bus and coach, fire and rescue, and construction and utility applications, and serve both OEM fitment and the replacement aftermarket.

Beyond seals and bearings, STEMCO builds axle fasteners such as the Auto-Torq and Pro-Torq, Kaiser king pins, brake products including drums and brake adjusters, and steering parts such as tie rods and drag links. It also sells intelligent transportation and fleet-technology products, including mechanical and electronic hubodometers, the DataTrac mileage sensor, and tire pressure monitoring, along with aerodynamic and fuel-optimization devices. As a Tier 1 and Tier 2 supplier to the commercial vehicle industry, STEMCO positions its catalog around durability, uptime, and total cost of ownership for fleets.

Ownership and history

STEMCO was founded in 1951 and takes its name from Specialized Truck Equipment Manufacturing Company. It marked its 75th anniversary in 2026, and remains focused on the commercial vehicle market it has served since the early 1950s. The company is headquartered in Longview, Texas, where it also runs a 10,000-square-foot Engineering Test Center, completed in 2005, that it uses to evaluate and benchmark both its own and competing wheel-end products.

STEMCO is a company of Enpro Inc. (NYSE: NPO), a publicly listed industrial manufacturer, and sits within Enpro's Sealing Technologies segment alongside Garlock and Technetics. STEMCO expanded through a series of acquisitions, adding V.W. Kaiser Engineering (king pins), Rome Tool and Die, and Motor Wheel Commercial Vehicle Systems, which broadened its steering and brake lines. Its manufacturing footprint is reported across Texas, Michigan, Tennessee, Kentucky, Georgia, and China. Day-to-day leadership sits with Chip Stuhr, named President in 2023 after more than 15 years in progressively senior roles at the company.

Financial backing

STEMCO does not publish standalone financial statements. Its parent, Enpro, reported total sales of $1,143.3 million for the full year 2025, and Enpro's Sealing Technologies segment, which includes STEMCO, grew sales 14.8 percent over the prior year. Enpro's 2025 reporting noted continued softness in commercial vehicle OEM demand offset by strength in aerospace, biopharma, and general industrial markets, so STEMCO operates inside a diversified, investment-grade parent rather than as a standalone reporting entity. Backing by a listed parent is the most concrete financial-stability signal available for STEMCO, since segment-level detail for the commercial vehicle line is not broken out publicly.

Certifications and quality

STEMCO states that it is ISO 9001:2015 certified, with a certificate posted on its own site that runs through 2027. The company emphasizes design validation through its Engineering Test Center, where it says it performs hundreds of tests each year across the full product lifecycle, from early concept development to audit testing of mature products. STEMCO also runs STEMCO University, an in-person and online training program for fleets and technicians, which it frames as part of its quality and safety mission of Making the Roadways Safer. These are the company's own claims about its quality system and are reported here as claims.

Known customers

Most STEMCO relationships are unnamed, as is normal for a wheel-end supplier serving OEM and fleet programs. One relationship is on the public record:

Beyond that documented agreement, STEMCO sells broadly into the North American truck and trailer market as an OEM and aftermarket supplier, and its parent's public reporting ties its demand to commercial vehicle build rates.

Sourcing evidence

STEMCO's US import record reads like a wheel-end manufacturer's should: 1,085 sea shipments since January 2015, most recently on September 15, 2026, dominated by bearings, brake and suspension parts, and steering components rather than finished goods. The pattern of components in, assembled and finished parts out is the signature of a domestic manufacturer sourcing globally, not a reseller. Bills of lading name the most active foreign suppliers:

By origin, China leads STEMCO's overseas supply by a wide margin, followed by Turkey, Brazil, and Italy. By HS chapter, the mix leads with tapered roller bearings and other bearings, followed by motor vehicle parts covering suspension, brakes, and steering. Customs-derived estimates put cumulative ocean shipping spend at roughly $1.2 million, with cost data covering about 48 percent of shipments, an order-of-magnitude figure rather than an audited one. This concentration in Chinese bearing and brake sourcing is directly relevant to buyers weighing tariff exposure and nearshoring options in commercial vehicle wheel-end supply.

Coverage caveats: these are US ocean-freight records only. Air, truck, and rail movements do not appear; some records name freight intermediaries rather than manufacturers; and product categories come from declared manifest codes, which are noisy. Absence of a record is not evidence of absence.

Frequently asked questions

What does STEMCO make?

STEMCO manufactures wheel-end and steering components for heavy-duty commercial vehicles, including wheel seals, hub caps, bearings, pre-adjusted hub assemblies, axle fasteners, king pins, brake products, and tie rods. It also sells fleet technology such as hubodometers, mileage sensors, and tire pressure monitoring. STEMCO describes itself as the No. 1 U.S. manufacturer of heavy-duty wheel-end seals.

Who owns STEMCO?

STEMCO is a company of Enpro Inc. (NYSE: NPO), a publicly listed industrial manufacturer, and sits within Enpro's Sealing Technologies segment alongside Garlock and Technetics. STEMCO was founded in 1951 and is headquartered in Longview, Texas.

Where is STEMCO headquartered?

STEMCO is headquartered in Longview, Texas, at 300 Industrial Blvd., where it also operates a 10,000-square-foot Engineering Test Center. The company reports additional manufacturing operations across Texas, Michigan, Tennessee, Kentucky, Georgia, and China.

Who are STEMCO's customers?

Most STEMCO customers are unnamed, as is standard for a wheel-end supplier, but one relationship is documented: in December 2023 STEMCO and Great Dane announced that STEMCO's Auto-Torq axle fastener would come standard on all Great Dane trailers. STEMCO supplies both OEM fitment and the commercial vehicle replacement aftermarket across North America.

What certifications does STEMCO hold?

STEMCO states that it is ISO 9001:2015 certified, with a certificate posted on its site that runs through 2027. It validates product designs through its in-house Engineering Test Center and runs STEMCO University training programs for fleets and technicians.

How long has STEMCO been in business?

STEMCO was founded in 1951 and celebrated its 75th anniversary in 2026. It has served the commercial vehicle industry continuously since the early 1950s and is now part of the publicly listed manufacturer Enpro.

Last verified September 28, 2026. Is this your company? Request a correction.