Zero quality control in manufacturing. The bit chuck is most often scrap, cut crooked so the bit goes in crooked and cannot be tightened enough to hold the bit securely. The barrel is steel and the cartridge tensioner is aluminum of very poor quality so aluminum shavings fly out every time you loosen or tighten it. It won't be long before all the threads are gone. Pretty much rubbish.
Hakko 599B 02 Wire Type Soldering Cleaner
11 Review
Hakko T18-BR02 Soldering Tip - T18 Series for Hakko FX-888/FX-8801 - Conical Shape - Bent 30 Degrees - R0.2 mm x 10.5 mm
12 Review
309LFC-O X .035 X 1LB Spool Gasless Stainless Steel Flux Core Welding Wire by Blue Demon
12 Review
π₯ Whizzotech Solder Wire 60/40 Tin/Lead with Flux Rosin Core - 0.032 Inch Diameter for Electrical Soldering (4oz/100g/0.22lb)
13 Review