Olympic Bar Diameter: Why They Aren’t All the Same

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 is in a section further below.

The diameter (thickness) of the shaft usually ranges from 25mm to 32mm on different bars, which converts to 0.98″-1.26″.

• 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 an all-purpose bar for all exercises for strength training purposes.
• 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 very heavy squat because it doesn’t dig in as much as thinner bars.

Fat Bars

There are also 1.5″ or 2″ thick “fat” bars, called axles because they’re so thick they look like car axles. They are 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. We did a review of Fringe’s 20kg fat bar.

They are often all one piece, so there are no sleeves that spin. That’s part of the appeal in strongman lifts, having an awkward object that you have to lift up without the benefit of the shaft turning as you get under it.

The other way they are sometimes made is with a normal sized shaft and a large 2″ pipe fitted over the shaft, with bushings for rotation, so technically the middle is the sleeved part rather than the ends. Same difference, I guess. Anyway, this can be a good bar for grip strength training, with the way it’s harder to hold onto for pulling movements. It is not appropriate for strongman training, due to the extra help the spinning provides.

Sleeves Diameter

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 49.8mm-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.

Any collars should squeeze a 50mm sleeve with the right snugness, including anything from simple spring collars to OSO collars to high-end competition collars. 

Weightlifting / IWF Specification

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.

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/technique before progressing to lifting more challenging weight. They are only made to handle up to 100 lbs or so and are not meant to be abused like steel bars. These are perhaps the rarest of any straight bars, outside of specialty weightlifting gyms.

Powerlifting / IPF Specification

The International Powerlifting Federation regulates the sport of powerlifting. It’s the original federation. The competition lifts are the back squat, deadlift and bench press.

The IPF gives a range of 28mm to 29mm for bar shaft diameter. Unlike the IWF, the IPF doesn’t specify a women’s bar. There are growing women’s divisions all over the place, but they simply use the men’s bars.

There are other organizations as well, such as the United States Powerlifting Association and USA Powerlifting, developed because they don’t like certain thingsa bout the IPF.

In practice, there are specialized squat and deadlifting bars that powerlifters like. These are 8ft long, and shaft diameters may be anywhere from 28mm to 32mm. So most powerlifting bars you’ll find online don’t fit the IPF specifications very well but are still considered useful powerlifting bars.