PT7240 & PT7250 Soft, Flexible Urethane Elastomers


The Shore A-40 and A-50 urethane systems described here are tough, soft, highly resilient polyurethane elastomers that have good handling characteristics and excellent cured properties. These high physicals make them ideally suited for applications such as bumpers, pads, flexible molds or soft parts where a high degree of flexibility and toughness is required. Their relatively high tensile strengths make them good performers for complicated masking or holding fixtures where the tooling needs to be stretched to apply and remove. These two systems are very low in viscosity, so they mix and pour with great ease. They will duplicate the finest detail without trapping air. They are very clear, and light amber in tint, so they can be easily pigmented if desired, for a broad range of finished part colors.

 Shore A-40 System
Shore A-50 System

  PT7240 APT7240 BPT7250 APT7250 BASTM Method 
AmberLight Amber
Light Amber
1175 cps
25 cps
1600 cps
20 cps
Specific Gravity, gms./cc
Mix Ratio, by Weight
100 : 75
100 : 70
Pot Life, 4 fl oz Mass @ 77°F
20 – 25 min.
18 – 22 min.


Generally, with polyurethane elastomers, full properties are developed in 7 days at room temperature (75°F). Temperatures below 75°F will lengthen the cure time, and if the ambient temperature is below 60°F, additional heat may be necessary for proper cure. Elevated temperatures will accelerate the cure of urethanes, but care must be taken if a higher temperature is used to cure the material. Generally, the higher the curing temperature, the greater the final cured shrinkage. When heat curing for more rapid processing, to best control shrinkage, the casting should be allowed to set for 12 to 18 hours at room temperature before an oven post cure. A typical accelerated curing cycle, therefore, would be: Allow to gel on the pattern for 12 to 18 hours at room temperature (70°F to 80°F), then post cure for a minimum of 8 hours at 150°F to 165°F and allow to cool before demolding. 


Gallon Kit
PT7240 Part A 8 lb.
40 lb.
PT7240 Part B
6 lb.
30 lb.
Kit14 lb.
70 lb.
PT7250 Part A8 lb.40 lb.
PT7250 Part B5.75 lb.
28 lb.
Kit13.75 lb.
68 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.

 PT7240 A/B
PT7250 A/BASTM Method
Mix Ratio, by Weight
100 : 75
100 : 70
ColorLight Amber
Light Amber
Mixed Viscosity, @77°F, centipoise
825 cps
950 cps
Working Time, 4 fl. oz. Mass @ 77°F
25 min.
20 min.
Cured Hardness, Shore D
40 A±5
50 A±5D2240
Shrinkage, in/in, Mold #1, Vol: .053 Gal.0006.0009D2566
Specific Gravity, grams, cc
Specific Volume,  cu. in./lb.
Tensile Strength, psi 
800 psi
775 psi
Elongation at Break, %
525 %
450 %
Tensile Modulus – 100% Elongation175 psi
200 psi
Tensile Modulus – 200% Elongation
300 psi
375 psi
Tensile Modulus – 400% Elongation
520 psi
550 psi
Tear Strength, Die C, pli 180 pli
165 pli
Compression Set, Method B45 %
30 %
Bashore Rebound 65 %
64 %
Taber Abrasion, H18 Wheel, 1000, grams, 1000 cycles, mg loss 6 mg
5 mg


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.