Iringi yahlukana kwinqanaba elinye kwaye igobile ibe yimo ye-helical.Oku kubangela ukuba iwasha isebenzise amandla entwasahlobo phakathi kwentloko yesiqhoboshi kunye ne-substrate, egcina iwasha iqinile ngokuchasene ne-substrate kunye nentambo yebholiti iqinile ngokuchasene ne-nut okanye intambo ye-substrate, idala ukukhuhlana ngakumbi kunye nokuchasana nokujikeleza.Imigangatho esebenzayo yi-ASME B18.21.1, DIN 127 B, kunye ne-United States Military Standard NASM 35338 (eyayisakuba yi-MS 35338 kunye ne-AN-935).