Thermostat Metal Parts and Strips

NN, Inc. Precision Engineered Products Group’s Polymet brand specializes in the manufacture of standard and special thermostat metal products ranging from strip to coils, helixes, stampings, and sub-assemblies. Using a proprietary controlled-atmosphere bonding process to ensure bond integrity and optimum performance, materials are made to close tolerances and specifications. Complete on-site testing facilities measure flexivity and resistivity, guaranteeing products of a consistently high quality to ASTM standards.

From prototype to production, the group’s experienced engineering team offers up-front technical assistance, samples, prototype development, and ongoing technical support.

Thermostat Metal Strip

Precision Engineered Products Group’s Polymet brand manufactures more than 62 types of thermostat metals, including ASTM standard materials. Its engineering team can also tailor a custom thermostat metal solution to the customer’s application. The group produces the industry’s thickest thermostat metals using its proprietary controlled-atmosphere bonding process. Thermostat metals are available in thicknesses ranging from 0.004 inch to 0.150 inch.


As an ISO 9001-certified material supplier to leading companies around the world, continuous improvement is a core principle. Process specifications are rigorously maintained for every item manufactured — ensuring exceptional lot-to-lot consistency and traceability. A rigorous testing protocol monitors key parameters such as flexivity, resistivity, and hardness.
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Customer Benefits

  • Controlled-atmosphere bonding process ensures bonding integrity
  • Industry’s thickest thermostat metals available
  • Exceptional lot-to-lot consistency and traceability
  • On-site testing facilities

Products and Capabilities


Thermostat metal spiral and helical coils are particularly suitable for use in thermometers, gauges, heating, refrigeration, and automotive applications where high rates of thermal deflection and mechanical force are required. Made from thermostatic metal alloys ranging in gauge from .004-inch to .150-inch thick, spiral and helical coils employ a wide range of inside and outside diameter combinations to suit the customer’s performance and space requirements. Inside and outside tab configurations can vary to suit assembly needs. PEP offers automatic, semiautomatic, and hand-wound coils, depending on volume and coil shape requirements.


Cantilever, simple beam, and U-shapes convert temperature change to mechanical force and movement where relatively small displacement is needed. Each configuration offers a specific kind of movement and benefits. Our engineering team works with customers to develop the right material and shape combination to obtain the desired performance. The group’s thermostat metal specialists produce the most intricate stamped parts to the highest standards in the industry.


Precision Engineered Products Group’s capabilities include manufacturing thermostat metal sub-assemblies by brazing, welding, staking, and crimping the components to minimize manufacturing steps and reduce costs. Its engineers collaborate with customers to determine the most efficient methods to achieve cost and design goals.


262 Broad Street
North Attleboro, MA 02760
Phone: +1 508.695.7700
Email: pepelectrical@nninc.com