What’s the typical diameter for an olympic bar?
First, let’s be clear about whether you’re talking about the end sleeves or the shaft (center portion). I’ll talk about the shaft first. More info on the sleeves below.
The diameter (thickness) of the shaft ranges from 25mm to 32mm, which converts to 0.98″-1.26″. (there are also specialty fat bars – see below)
- 25mm (0.98″) is reserved for women’s weightlifting bars. Women typically have smaller hands that can’t do a hook grip on a 28mm bar as easily, and 25mm was developed to take that into consideration.
- 28mm (1 1/16″) is the minimum size for a men’s bar and generally provides the best grip for pulling movements like the deadlift and clean-and-jerk, and it lets the bar flex or “whip” somewhat during heavy lifts to help facilitate dynamic movements like the clean-and-jerk.
- 28.5mm (1 1/8″) is more common than a true 28mm. Non-competition olympic lifters find this size acceptable. It’s also a good size for a general-use bar for all exercises.
- 29mm (1 1/8″) is a common size for powerlifting exercises. The extra thickness is a little more comfortable for presses so the bar doesn’t dig into your palms as much, and it’s a little stiffer to prevent whip. It’s still small enough that you can get a good grip on it for deadlifts.
- 30mm (1 3/16″) is an optional size for bench pressing. It’s a little too thick for effective deadlifts and cleans without losing your grip prematurely, but for pressing it’s not a problem. Still, some lifters prefer a 29mm bar for pressing.
This is also about the size that cheap bars in 300 lb olympic weight sets are. A thicker bar is one way of increasing the strength of a bar without using better steel. That isn’t the only reason for a thicker bar, but in the case of cheap bars it is.
- 32mm (1 1/4″) is often preferred for powerlifting style squats, because the extra thickness makes the bar really stiff and less prone to wobble as the lifter bounces out of the bottom of the squat. And it’s a little more comfortable on the shoulders during a squat because it doesn’t dig in as much as thinner bars.
There are also 1.5-2″ thick “fat” bars, called axles because they’re so thick they look like car axles, used in strongman competitions. The solid steel ones weigh 80-100 lbs, so sometimes these are made with hollow pipes to save on weight and cost.
They are often all one piece, so there are no sleeves that spin. The othe way they are sometimes made is with a normal sized shaft and a large 2″ pipe fitted over it with bushings for rotation, so technically the middle rotates instead of the ends. Same difference, I guess.
In general, an olympic bar is easily identifiable from a standard bar in that the end sleeves of an olympic bar for loading weight plates are 50mm (1.97″) thick. A standard bar has 1″ thick ends.
One reason the sleeves are so thick is they are made to spin, so they have to fit a strong shaft inside of the sleeve as well as bushings or needle bearings to facilitate the spin of the sleeves on the shaft. Standard 1″ bars don’t spin and don’t have that problem.
Fitting Barbell Plates and Collars
In the past I’ve found some sleeves of cheap olympic bars to be a little more than 50mm thick. This causes a critical problem when you have snug-fitting (ie: high quality) weight plates. I haven’t run into that for years, but it’s possible that some brands of the cheapest bars have this problem. The last time this happened on a bar I sold to a customer was probably 2010 or earlier, I believe a $90 short 5ft bar (which is very cheap for a bar). It was just one sleeve with the issue, not the other side, so it was a quality control issue. I of course replaced it for him.
Anyway, whether they’re iron plates, rubber coated plates, or bumper plates, good weight plates should fit fairly snugly so that there isn’t much clanking sound or any slack when you’re pulling it off the floor.
The International Weightlifting Federation (IWF) regulates the sport of olympic weightlifting, consisting of the competition lifts the snatch and the clean-and-jerk.
These are sometimes what people refer to when they say “olympic bar,” but olympic bar might also refer to any bar with 2″ sleeves, including powerlifting bars (below). To be more specific they are also called “oly bar”, “WL bar”, or “weightlifting bar”.
The IWF specifies 28mm for the men’s bar and 25mm for the women’s bar. In practice, male non-competition lifters will make use of a 28.5mm bar.
The women’s weightlifting bar has a 25mm shaft to better fit women’s smaller hands.
I should mention that there are also “technique” bars that might be any diameter. These are special 15lb light weight bars (usually aluminum) for learning form.
The international Powerlifting Federation regulates the sport of powerlifting. The competition lifts are the back squat, deadlift and bench press.
The IPF gives a range of 28mm to 29mm. Unlike the IWF, the IPF doesn’t specify a women’s bar.
In practice, there are specialized squat and deadlifting bars that are 8ft long, and shaft diameters may be anywhere from 28mm to 32mm. So most powerlifting bars you’ll find online don’t fit these specifications very well but are still considered powerlifting bars.