Measured in PSI — determines load before permanent deformation. <150K = budget, bends under heavy squats. 180-200K = home gym sweet spot. 200K+ = competition-grade. A 190K bar yields at ~120K PSI — enough for 700+ lb deadlifts.
Minimum Spec
For loads over 300 lbs: 180K+ PSI, 28.5mm shaft (men's), quality knurling. Everything else is preference.
What is the difference between a cheap and expensive barbell?
Steel quality, bearing type, knurl quality, whip characteristics, and coating durability. A $150 bar bends permanently under heavy loads. A $300+ bar lasts decades.
Do I need a specialty barbell?
A quality Olympic barbell handles 90% of exercises. The trap bar is the most useful specialty addition.