Neck Finish Guide

Neck Finish Guide

By: Berlin Packaging Specialist
Date: October 20, 2019

Understanding a container’s neck finish is an important step in proper closure/bottle sourcing. Below the various neck finish dimensions are explained.

"I" Dimension

The inner diameter of the bottle neck. Specifications require that a minimum "I" to allow sufficient clearance for filling tubes. Linerless closures, with a plug for land seal, and dispensing plugs for fitments require a controlled "I" dimension for a proper fit.

"T" Dimension

The outside diameter of the thread. The tolerance range of the "T" dimension will determine the mate between bottle and closure.

"E" Dimension

The outside diameter of the neck. The difference between the "E" and "T" dimensions divided by two determines the thread depth.

"H" Dimension

The height of the neck finish. Measured from the top of the neck to the point where the diameter "T" extended down, intersects the shoulder.

"S" Dimension

Measured from the top of the finish to the top edge of the first thread. The "S" dimension is the key factor determining the orientation of the closure to the bottle and the amount of thread engagement between the bottle and cap.

 

If you have any questions regarding neck finishes or products, please contact a Packaging Specialist at 1.800.2.BERLIN.