The inserts to the mold are the likely culprit. As the inserts wear (probably more so during cleanings I suspect) and result in smaller internal diameters. Draft angle in the mold also contribute to tighter fits at the base. Plastic shrinkage factors also come into play either due to composition or temperature of the mold during ejection. Since these are mass produced using cheap/inexpensive plastic there is significant variability tool-to-tool and lot-to-lot. One batch you buy may work out but not the next. As folks here have stated, return and replace. However, these are also bought and sold in bulk. Chances are your source is sitting on a pile of discrepant tubing. You may need to return for a refund and wait a bit before buying again.
Posted 03/26/2017 10:20 am
