Olympic bar diameter – Why they aren’t all the same

By | 2017-06-05T18:14:47+00:00 July 14th, 2016|Categories: Equipment Guides|Tags: |4 Comments

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.

deadlift grip

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.barbell shaft thickness
  • 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.squat bar position
  • 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.

Fat 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.

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 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 Lock Jaws to high-end WL and PL competition collars

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. 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.

IPF Specifications

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.

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About the Author:

David Kiesling
David founded Adamant Barbell in 2007. He is into weight training, Crossfit, nutrition, hang gliding, snowboarding, mountain biking, and hackysack. He also owns a hang glider repair business.

4 Comments

  1. Chad Walls September 23, 2017 at 4:23 pm - Reply

    I decided to measure the diameter of both of my bars just to be certain. The new bar I purchased measures 30.2 mm in diameter. The older bar that I have been using for years was surprisingly 34.4 mm in diameter. It is no wonder I was having such difficultly gripping with this bar. lol.

    • David Kiesling
      David Kiesling September 24, 2017 at 7:20 am

      Wow, 34mm is a thick bar. Any idea what brand? I don’t know that I’ve ever seen one that thick, other than specialty fat bars that are 1.5″ (38mm) or more.

  2. Chad Walls - Fitness Blog September 21, 2017 at 8:30 am - Reply

    Thanks for this post! I have been training for the past two years at home with an Olympic bar with a thicker shaft and often had difficulty with my grip. I recently purchased a second bar and soon discovered that it felt easier to grip especially double overhand. I used to think I had a weak grip but having a bar with a thinner shaft makes a huge difference. I don’t have a caliper to measure but it is nice to know from reading your blog that there could be as much as a 1/4″ difference in diameter.

    • David Kiesling
      David Kiesling September 21, 2017 at 9:06 am

      Yep, it makes a big difference when it gets heavy! Deeper knurling can also add a good chunk to your raw max. I use straps on my heaviest deadlifts, but I switched things up from the CAP OB-86B to a Troy GOB-1800 bar last workout, which has a little more aggressive knurling than the pretty soft CAP knurling, and I could go up to 300 lbs before my double overhand grip was going to fail me (a mixed grip makes me scared I’m gonna pull a muscle) and I had to put on the straps.

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