a9cc56f1____Group_15___2012___GICL_Wiki__3
[0] Long Torx Screws [1] 4 [2] 3 [4] Steel [5] Durability, strength, and cost. [6] Screw cutting lathe. [7] Necessary for the production of screws, cost effective. [3] 
Provide removable connection points and stability between two or more parts. (For longer distances/greater stability)
Gate 3 - Group 15 - 2012 - GICL Wiki