Don't distract me, I'm thinking.Screw
A talented mechanic, he is (allegedly) able to make a tank out of a farm tractor. Regardless of the veracity of the claim, he is a very talented fellow, in charge of repairing various vehicles used by Freedom. His workshop is located on the military base's helipad.
Shadow of Chernobyl
Screw is located at the Freedom base in the Army Warehouses. He was most likely meant to be able to repair weapons and/or armor, but the feature never made it into the final game. He has a very small optional mission in which he'll give you a PSO-1 Scope if you bring him a bottle of vodka. Usually you can buy vodka from Skinflint or Chef, both of whom are very close by.
Originally Screw was supposed to fix and repair your weapons, but this was removed from the game. Though this can be recuperated via multiple mods, such as the Zone Reclamation Project.
- S.T.A.L.K.E.R.: Shadow of Chernobyl 220.127.116.11, stable_bio_name.xml; id=mil_Svoboda_engineer_bio: A mechanic renowned throughout the Zone. Can make a tank out of a tractor or so the story goes.