Dimensionally-stable tooling board with low CTE

Featured Product from General Plastics Manufacturing Co.

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High Temperature, Low CTE Tooling Material
Download the FR-4800 Tooling Guide PDF.

LAST-A-FOAM® FR-4800 is a high-temperature tooling board with low CTE which can be used with high-temperature resin systems, such as vinyl esters, epoxies and BMIs, in high-pressure autoclaves and fiber-reinforced composites.

It can withstand peak temperatures up to 480°F (249°C) and continuous use temperatures up to 400°F (204°C). The FR-4800 tooling board is significantly better than other plastics in the market because it does not warp or twist even at elevated temperatures. It will not change shape throughout the course of thermal cycling, preventing out-of-tolerance parts. Furthermore, its predictable and repeatable CTE makes it easy to calculate a tooling correction factor which helps improve the ability to produce high-tolerance parts. This is especially important in the production of parts for the aerospace, defense and automotive industries.

The FR-4800 tooling board will machine well with traditional aluminum tools. The FR-4800 does wear cutting tools much faster than other LAST-A-FOAM® products. As a result, carbide tooling is recommended. It is also recommended you do a rough cut first, leaving an extra 1-3 mm for finishing. Use caution with edges and tight corners to avoid chipping at the start of a new pathway.   Consult our FR-4800 Tooling Guide for additional CNC machining recommendations.

Sealant Compounds
The FR-4800 is designed with a hard, smooth finish and does not require the use of a sealant compound. However, if planning to apply a liquid mold release agent, sealing the tool surface is recommended.  Consult our FR-4800 Tooling Guide for a detailed list of recommended products.


  • Peak temperatures up to 480°F (249°C)
  • Continuous use temperatures up to 400°F (204°C)
  • Low, predictable and repeatable CTE
  • Consistent cool-down rate (1°F to 2°F per minute)
  • Fully-cured, no outgassing
  • Dimensionally predictable at elevated temperatures
  • Easily machined, doesn’t chip out
  • Static-dissipative
  • Offered at 48 pounds per cubic foot
  • Made in USA



  • Fiber-reinforced composites
  • High temperature resin systems
  • High-pressure autoclave
  • Foam master
  • Prepreg composite layup tools
  • Vacuum forming
  • Short-run tooling
  • Pattern making
  • Monolithic tools and molds
  • Prototype tooling


Technical data sheet

Product data sheet

For over 75 years, we have focused on meeting the exacting requirements of engineers and design teams in diverse industries. Our premier LAST-A-FOAM® closed- and open-cell polyurethane foam products provide a high strength-to-weight ratio and extraordinary versatility, with absolute consistency from order to order, guaranteed.

Whether you need high-temperature tooling boardsmolded parts or submersible foams, expect identical quality, uniformity, stability and weight for the density you specify – every time.

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