ዓይነ ስውራን ዝላይ ጭንቅላት፡- ሚስጥሩ የጥፍር ጭንቅላትን ስለማይጠቀልለው የእንቆቅልሹን ዝላይ ጭንቅላት ያስከትላል። https://www.yukerivet.com/news/the-core-of-the-blind-rivet-is-not-completely-pulled out-what-is-the-reason-for-the-fracture/ የልጥፍ ሰዓት፡- ጁላይ-28-2022
