Verified Nov 2026
Lighting
·
Warren, Michigan
·
Since 1971
Proper Group International is an engineering and manufacturing firm headquartered in Warren, Michigan, United States, founded in 1971. It is privately held and has an estimated 500 to 1,000 employees and an estimated revenue band of $100M to $250M. The company makes plastic injection molds, runs production injection molding and precision machining, and serves the automotive, electric-vehicle, and industrial-equipment sectors. Its Proper Polymers division produces plastic sub-components, and the company also builds cockpit modules and air induction systems for automotive customers.
Proper Group International at a glance
Revenue
$100-250M
Est. band
Employees
500-1,000
Founded
1971
Headquarters
Warren, Michigan
Import activity
29
Industries
Automotive
Electric Vehicles
Industrial Equipment
Sourcing and import activity
From US customs bill-of-lading records
US sea imports
29
Named foreign suppliers
3
Top origins
Netherlands · Belgium · Hong Kong S.A.R. · Germany
Shared foreign counterparties do not establish that these companies buy from Proper Group International.
What this tells a buyer
No customs trade records are available for this company, so its import and export footprint cannot be described.
Capabilities listed for the company include plastic injection mold design and manufacture, rapid prototyping, thin-wall and multi-shot molding, and precision machining, with no certifications recorded in the directory.
The company is privately held, and its revenue figure is an estimated band rather than a reported number.
Source: US customs bill-of-lading records and public filings · Last verified Nov 05, 2026
Overview
Proper Group International is an engineering and manufacturing firm headquartered in Warren, Michigan, United States, founded in 1971. It is privately held and has an estimated 500 to 1,000 employees and an estimated revenue band of $100M to $250M. The company makes plastic injection molds, runs production injection molding and precision machining, and serves the automotive, electric-vehicle, and industrial-equipment sectors. Its Proper Polymers division produces plastic sub-components, and the company also builds cockpit modules and air induction systems for automotive customers.
At a glance
Attribute | Detail |
|---|---|
Founded | 1971 |
Headquarters | Warren, Michigan |
Employees | 500-1,000 |
Revenue | $100-250M (estimated) |
Primary capability | Lighting |
What Proper Group International makes
Capabilities listed for the company include plastic injection mold design and manufacture, rapid prototyping, thin-wall and multi-shot molding, and precision machining, with no certifications recorded in the directory.
Trade and customs footprint
No customs trade records are available for this company, so its import and export footprint cannot be described. US customs bill-of-lading records list 29 inbound shipments across 3 foreign suppliers, with top origins including Netherlands · Belgium · Hong Kong S.A.R. · Germany.
Company details
The company is privately held, and its revenue figure is an estimated band rather than a reported number. Proper Group International was founded in 1971, has an estimated 500-1,000 employees, and is headquartered in Warren, Michigan.
Frequently asked questions
What does Proper Group International make?
Proper Group International is an engineering and manufacturing firm headquartered in Warren, Michigan, United States, founded in 1971. It is privately held and has an estimated 500 to 1,000 employees and an estimated revenue band of $100M to $250M. The company makes plastic injection molds, runs production injection molding and precision machining, and serves the automotive, electric-vehicle, and industrial-equipment sectors. Its Proper Polymers division produces plastic sub-components, and the company also builds cockpit modules and air induction systems for automotive customers.
Where is Proper Group International headquartered?
Proper Group International is headquartered in Warren, Michigan (13870 E 11 Mile Rd, Warren, Michigan, 48089).
When was Proper Group International founded?
Proper Group International was founded in 1971.
How big is Proper Group International?
Proper Group International has an estimated 500-1,000 employees, with revenue in the $100-250M range (estimated).
Does Proper Group International import from overseas suppliers?
US customs bill-of-lading records show 29 inbound shipments for Proper Group International, with top origins including Netherlands · Belgium · Hong Kong S.A.R. · Germany.
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Last verified Nov 2026. Is this your company? Request a correction.
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