Profile: Ajax-Custom Plastic Mfg. Corp. is a manufacturer of plastic and metal products. Our products are used in medical, semiconductor, data communication and food process equipment industries. We provide thermoforming, molding, machining, fabrication, welding and assembly services. Our plastic sheet thermoforming is a simple process of applying heat to plastic sheets until pliable and then forming them into the desired mold shape by using vacuum, pressure, gravity & mechanical aides.