Step 1: Parts......
2) 1x 1N4001 - 4007 diode
3) 1 x cell phone charger connector pin( female)
4) 1x resistor of abt10 ohm or try( the led resistor calculator online )
5) 1x circuit board ( or PCB if you ll get one!)
6) soldering iron
7) wire cutters ( also you will need cutters to cut short the circuit board)
8) some small plastic bottles or a large heat shrink tubing ( to cover the steel case)
9) some insulating tape
10) lens for led ( make its focus wider) very use full
12) 1x switch
13) a drilling machine or a pointed screwdriver ( to make hole on the plastic case for the switch)
14) a li ion battery 3.7 v ( like the one in my previous instructable https://www.instructables.com/id/Rechargeable-wallet-LED-torchwith-usb/)
Step 2: Procedure.... Cut the Steel Pipe
Step 3: The Circuit
TIP!! :-) place the components as close as you can so that the circuit board will fit in the steel case)
Step 4: Installing the Switch
Step 5: Finishing Steps
place the circuit board in the steel case and also place the led and the lens over it.
you will need to glue the case from the top or just secure it with a duct or transparent tape.
so that you can hack it open something goes wrong...