DESIGN & INSTALLATION TECHNOLOGY

BASIC DESIGN GUIDELINES

BOSS DIAMETER: The outside diameter of a post which encompasses an insert. Boss diameter is a determining factor in the holding retention strengths achieved by an insert.

	STRAIGHT HOLE: Outside boss diameter on insert designs should be equal to or greater than one and one half to two times the diameter of the insert being used, to avoid fracturing or stress on the boss, and to achieve optimum performance.
	TAPERED HOLE: Outside boss diameter on the insert designs should be equal to or greater than two to three times the diameter of the insert being used, to avoid fracturing or stress on the boss, and to achieve optimum performance.
	EXPANSION HOLE: Boss diameter on the insert designs should be equal to or three times the diameter of the insert being used, to prevent fracturing or stress on the boss, and to achieve optimal performance.

HOLE DEPTH: The total depth of the post in which the insert is to be placed. Proper hole depth is a determining factor in achieving a flush (or .005" below) installation of the inserts, as well as preventing any excess plastic from flowing into the threads. The depth of the hole should be equal to the insert length plus .010" to contain any flash that might be displaced.

CORE PINS: The pins in the mold which allow for the hole size in the molded piece. Core pins are designed allowing for shrinkage of the plastic.

THREAD: Class of thread fit for all standard products is UNC-2B for inch threads and ISO-6H for metric threads.

MATERIAL: Generally inserts are manufactured in brass. Other materials are available upon request PLATING: Plating is available for most inserts.

INSTALLATION METHODS

ULTRASONIC INSERTION: Ultrasonic vibrations travel through the inserts to the plastic material surrounding the insert. The intensity of heat created by the plastic vibrating against the metal is sufficient to melt the plastic momentarily, allowing the plastic to flow into the knurls, fins and undercuts of the insert. The plastic solidifies upon completion of the cycle, permanently locking in the insert.

INDUCTION: Induction heats the OD (outside diameter) of the insert where the metal to plastic interface is vital. The advantage of this procedure is the thread is not exposed to a significant amount of heat or extended exposure of heat. The strength of the thread remains intact.

MOLDED-IN: One of the oldest installation methods used today is molding an insert into a plastic part during the mold cycle. The plastic flows around the insert which is held on a pin during the molding cycle. EIS offers a complete range of thru-hole and blind-hole threaded Magnaserts.

POST-MOLDED COLD PRESS: Another installation method commonly used is post-molded cold press insertion. An insert is pressed in cold into a drilled or molded hole. A slotted expansion insert or a solid thru-thread insert can be pressed in cold with a press.

THERMAL INSERTION: The plastic melts and flows into the undercuts, knurls and fins. Then the heated fin is removed allowing the insert and plastic surrounding the insert to solidify, locking the insert in place.

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