Ko'r perchinli jumper nimani anglatadi?

Perchinning sakrash boshi ko'r: chunki perchin tirnoq boshini o'ramaydi, bu perchinning sakrash boshiga olib keladi.

https://www.yukerivet.com/news/the-core-of-the-blind-rivet-is-not-completely-pulled-out-what-is-the-reason-for-the-singan suyak/