Thermoseal ML-S723 is a controlled-swell gasket material intended for heavy-duty applications. ML-S723's blended styrene butadiene and natural rubber binder provides exceptional sealability and conformability with low creep relaxation. Thickness increase, in the presense of oils and fuels, aids the sealing of irregular flange surfaces. Its unique Multi-Layer Technology structure provides exceptional low flange pressure sealability with exceptional torque retention. Multi-Layer Technology sheet products consist of a reinforced high density core with conformable sealing layers on each side. Typical applications include diesel engine oil pan gaskets and gear plate and rear seal carrier gaskets with intermittent operating temperatures up to 350° F (177° C).

Ref. Thickness of Measured Values



maximum 350 F° (177 C°)


maximum 435 psi (3 MPa)

Density ASTM F1315

100 lbs/ft3 (1.6 g/cm³)

Compressibility ASTM F36J


Recovery ASTM F36J

minimum 40%

Weight Increase ASTM F146

After immersion in Fuel B for 5 hrs. at 73° (23° C)


maximum 35%

Thickness Increase ASTM F146

After immersion in ASTM Oil #1 for 5 hrs. at 300° F (149° C)

After immersion in Oil IRM903 for 5 hrs. at 300° F (149°)

After immersion in Fuel A for 5 hrs. at 73° F (23° C)


0 - 10%

30 - 40%

0 - 15%

Creep ASTM F38B (1/32")

maximum 35%

Sealability ASTM F37

<0.20 ml/hr

ASTM F104 Line Call Out


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