Pali mitundu yosiyanasiyana ya njerwa zopanda kanthu, zomwe zimatha kugawidwa m'mabwalo wamba, midadada yokongoletsera, midadada yotsekera matenthedwe, midadada yotulutsa mawu ndi mitundu ina malinga ndi ntchito zawo. Malinga ndi mawonekedwe a block block, imatha kugawidwa mu block block, block yosasindikizidwa, grooved block ndi grooved block. Itha kugawidwa mu lalikulu dzenje chipika ndi kuzungulira dzenje chipika malinga ndi kabowo mawonekedwe. Itha kugawidwa kukhala chipika cha dzenje la mzere umodzi, chipika cha dzenje la mizere iwiri ndi chipika cha mizere ingapo malinga ndi dongosolo la ma cavities. Itha kugawidwa mu konkriti wamba midadada ang'onoang'ono dzenje ndi kuwala aggregate midadada ang'onoang'ono dzenje malinga aggregates. Hercules mtundu dzenje njerwa mzere kupanga makina ndi mkulu-mapeto kasinthidwe chitsanzo cha Honcha Company, amene ophatikizidwa ndi luso padziko lonse, "Mtima kusuntha dongosolo" zipangizo zake utenga luso patenti ya Honcha Company, bwino amaona mafananidwe wololera magawo osiyanasiyana a zipangizo mu akamaumba mkombero, ndipo amaonetsetsa kukhulupirika mkulu, mphamvu mkulu ndi kulamulira chiŵerengero cha zinthu kompyuta mwa kuphatikiza mankhwala. Mwa kusintha nkhungu kapena kusintha magawo a zida, mitundu yosiyanasiyana ya njerwa zopanda kanthu zimatha kupangidwa. Mzerewu umagwiritsidwa ntchito kwambiri kwa opanga njerwa zazikulu, zapakati komanso zazing'ono.