PT4976 A/B Aluminum Filled High Temperature Casting System


PT4976 is an epoxy casting system with exceptionally high heat resistance and very good physical properties. It has a high aluminum content, which gives it high compressive strength, tough, durable cured properties, and makes the finished castings very easy to machine if required. PT4976 performs quite well in a variety of demanding applications where the casting will be exposed to high loads and stresses at elevated temperatures.

 PT4976 A
PT4976 B
ASTM Method 
400,000 cps*
3000 cps
Specific Gravity, gms./cc
Mix Ratio, by Weight
100 : 15
Pot Life, 4 fl oz Mass @ 77°F
3 hours

*NOTE: PT4976 Part A has a very high aluminum content, and, as with all filled materials, there may be instances where the filler will settle out. As such, it is recommended that the Part A be stirred thoroughly before each use to redisperse the fillers to a uniform consistency.


PT4976 will gel at room temperature, but it is designed for and intended to be heat cured to obtain the high physical properties and heat resistance it is capable of. Therefore, an oven heat cure is mandatory for this product. The mixed viscosity of 40,000 centipoise plus the weight of the mixture enables PT4976 to flow well and pick up detail nicely. The long pot life slows plenty of time to release trapped air for solid, dense finished castings.
A typical cure cycle for PT4976 would involve an overnight cure at room temperature (77°F minimum), followed by an oven post cure of 2 to 3 hours each at 150°F, 250°F, 350°F, 400°F and finally 450°F. This cycle can be modified slightly to suit specific equipment requirements or time restraints, but always remember that it is important to give the casting sufficient heat cure time to reach full cured properties. In general, start the heat cure cycle as low as possible, and proceed with as many incremental steps as time and equipment permit, to obtain the best cured properties.


Gallon Kit
Pail Kit
PT4976 Part A
13.25 lb.
53 lb.
PT4976 Part B
2 lb.
8 lb.
Kit15.25 lb.
61 lb.

Inasmuch as PTM&W Industries, Inc. has no control over the use to which others may put material, it does not guarantee that the same results as those described herein will be obtained. The above data was obtained under laboratory conditions, and to the best of our knowledge is accurate. This information is presented in good faith to assist the user in determining whether our products are suitable for his application. No warranty or representation, however is intended or made, nor is protection from any law or patent to be inferred, and all patent rights are reserved. Before using, user shall determine the suitability of the product for his intended use, and user assumes all risk and liability whatsoever in connection therewith. In no event with PTM&W Industries, Inc. be liable for incidental or consequential damages. Buyer’s sole and exclusive remedy in such instances shall be limited to replacement of the purchase price.

 PT4976 A/B
ASTM Method
Mix Ratio, by Weight
100 : 15
Mixed Viscosity, @77°F, centipoise
40,000 cps
Working Time, 4 fl. oz. Mass @ 77°F
3 hrs
Cured Hardness, Shore D
90 Shore D
Specific Gravity, grams, cc
Density, lb./cu. in.
Specific Volume,  cu. in./lb.
Tensile Strength, psi 
7649 psi
Elongation at Break, %
.38 %
Compressive Strength, psi
33,163 psi
Glass Transistion Temperature, DMA:
370.6°F Onset
443.5°F Peak

** The properties listed in this bulletin were obtained with a cure of: Overnight at 77°F, followed by 2
hours each at 200°F, 300°F, 350°F, 400°F and 450°F.


PTM&W epoxy products are made from raw materials carefully chosen to minimize or even eliminate toxic chemicals, and therefore offer the user high performance products with minimum hazard potential when properly used.  Generally, the PTM&W epoxy resins and hardeners will present no handling problems if users exercise care to protect the skin and eyes, and if good ventilation is provided in the work areas.  However, all epoxy resins and hardeners can be irritating to the skin, and prolonged contact may result in sensitization; and breathing of mist or vapors may cause allergenic respiratory reactions, especially in highly sensitive individuals.  As such, avoid contact with eyes and skin, and avoid breathing vapors.  Wear protective rubber apron, clothing, gloves, face shield or other items are required to prevent contact with the skin.  In case of skin contact, immediately wash with soap and water, followed by a rinse of the area with vinegar, and then a further wash with soap and water.  The vinegar will neutralize the hardener and lessen the chances of long term effects.  Use goggles, a face shield, safety glasses or other items as required to prevent contact with the eyes.  If material gets into the eyes, immediately flush with water for at least 15 minutes and call a physician.  Generally, keep the work area as uncluttered and clean as possible, and clean up any minor spills immediately to prevent accidental skin contact at a later time.  Keep tools clean and properly stored.  Dispose of trash and empty containers properly.  Do not use any of these types of products until Material Safety Data Sheets have been read and understood.