Parts of a Barbell – Shaft, Sleeves, Knurling, Collars

All 8 parts on the diagram

Show the list

Whole barbell 4

Shaft The middle section of the bar, which the lifter grips.
Sleeve The end of the bar that the plates slide onto. It turns freely on the shaft.
Plates Round weights that slide onto the sleeves, the same on each side.
Collar A clamp on the sleeve that keeps the plates from sliding outward.

Up close 4

Knurling A crosshatch pattern cut into the shaft to give a solid grip.
Center knurling A patch of knurling in the middle of the shaft. Some bars have none.
Knurl marks Smooth rings in the knurling. They show where to place the hands.
Bushings Rings inside the sleeve that let it turn on the shaft. Some bars use bearings.

How this list was compiled: Every name checked on 2026-09-30, a name kept only where two independent sources use it: Wikipedia, text only: Barbell (bar and shaft, knurled crosshatch pattern for grip, weight plates that slide onto the outer portions of the bar, collars that stop the plates moving outward, rotating sleeves, center knurl, grip marks, bushings and bearings); the Visual Dictionary Online (QA International), https://www.visualdictionaryonline.com/sports-games/strength-sports/fitness-equipment_5.php (barbell: bar, sleeve, collar, disk); a powerlifting federation's technical rules book of 2022, https://www.powerlifting.sport/fileadmin/ipf/data/rules/technical-rules/english/IPF_Technical_Rules_Book_2022_1.pdf (bar, knurling, machined markings, sleeve, collars, discs); and a gym equipment review site's page on barbell anatomy, https://www.garagegymreviews.com/barbell-anatomy (shaft, sleeve, collar, knurling, center knurling, knurl marks, bushings, bearings). Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain geometry; no maker's mark, nothing traced. Licence: own work

How it works

A barbell is a long bar with weights at both ends, lifted with two hands. The first drawing shows a loaded barbell; the second shows the shaft up close and one sleeve cut open.

Read the full guide

The whole bar, then the details

Numbers 1 to 4 are on the whole barbell: the shaft, a sleeve, the plates and a collar. Open the second drawing for 5 to 8. The upper picture is the shaft drawn larger: find the knurling, the center knurling and the knurl marks. The lower picture is a sleeve cut open, with the bushings it turns on.

Plates are also called discs. Either answer is accepted.
The knurl marks are the smooth bands, not the rough ones.

Questions and answers

What are the parts of a barbell called?

The shaft is the middle section the lifter grips. A sleeve at each end carries the plates, and a collar locks them on. The rough crosshatch on the shaft is the knurling.

What are the ends of a barbell called?

The sleeves. The plates slide onto them. A sleeve turns freely on the shaft, on bushings or bearings inside it.

What is the rough part of a barbell called?

Knurling. It is a crosshatch pattern cut into the shaft to give a solid grip. The smooth rings inside the knurling are knurl marks, and they show where to place the hands.

What holds the weights on a barbell?

A collar. It clamps onto the sleeve outside the plates and keeps them from sliding outward.