Northern Indiana Manufacturing Pulleys.
Made in Indiana.
Used around the world.

Electro-Seal Sight Glasses.
Made in Indiana.
Used around the world.

Sight Glasses

Electroseal (73)

Electro-Seal is the leading producer of fused glass-to-metal, hermetically sealed sight glasses in North America.  We provide both high- and low-pressure solutions for a wide range of industries. Sight applications benefiting from the use of our products are in the food, dairy, beverage, pharmaceutical, construction, petroleum and chemical industries, among others. 

With over 29 Screw Machines, 17 CNC Lathes and 3 Vertical Machine Centers, we offer contract manufacturing services for machined parts and products. With a dynamic production setup process and diverse engineering expertise, we have extensive experience producing a wide array of products for many of the world’s largest companies.

We have become the dominant source for aftermarket pulleys in the United States, with a product line that includes over 375 alternator pulleys. If we do not already produce it as a standard SKU, our team will gladly work to produce whatever specialty solution may be necessary for your situation.

​From the bottom of the ocean to the far reaches of space, our incredibly precise, yet undeniably straightforward components provide a critical measure of visual verification for fluids, gases and powders in just about every piece of heavy equipment or industrial installation you’ll find.

Perseverance Pays Off


As a sister company to Northern Indiana Manufacturing, Electro-Seal has roots dating back to 1946. At that time, the company known as Northern Indiana Screw Machine Products established itself as a leader for precision screw machine parts for the automotive and heavy machinery industries, producing turned components, such as sight glass bushings on manual, single-spindle automatic, and multiple-spindle automatic lathes.

Northern Indiana Manufacturing produces fused glass-to-metal products and components that are hermetically sealed under the name Electro‑Seal. We are an original equipment product manufacturer (OEM) and provide contract manufacturing services. As an OEM, we build product SKUs for stocking two distinct product lines. One, for sight glasses, and the other for alternator pulley motor applications. As a contract manufacturer, we responsibly build-to-print for customers as needed, with the same high-level quality processes and procedures we expect and use for building our own products. Please visit the area of our Web site you are most interested in and Contact Us for additional information.