Barbells are broken into a few main parts: sleeves, collars, bearings or bushings and the shaft. The shaft of the barbell, the long center area of the barbell, will have a distinguished texture designed to help people hold onto the barbell when performing lifts. The knurling is the textured area of the barbell. However, not all knurlings are created equal. Hopefully, we can help you better understand the knurling to aid you when choosing a barbell.
Barbell Knurling Defined
Knurling is a process to create crossing, perpendicular lines on a metal surface in an effort to increase its aesthetics or to increase grip on the material.
A barbell’s knurling is the textured, “grippy” area located on the shaft of the barbell. The pattern consisted of a series of etched out diamond-shaped bumps designed to provide increased grip compared to a smooth piece of cylindrical metal. The knurling pattern is created by multiple sets of diagonal lines that go in opposite directions. A diamond-shaped raised area is results from these diagonal cuts, and we consider this the knurling.
Knurling is found on both Olympic barbells and standard barbells. Olympic barbells typically have a better knurl (more on knurl types below). If you’re wondering about the difference between Olympic and standard barbells, or which you should buy for your home gym, then you should check out my article comparing the two types of barbells.
Why The Knurling is on a Barbell
One of the most frustrating things is when you miss a deadlift or bent over row because the bar slips out of your hand. This would be much more commonplace if the shaft of the barbell was smooth because there would be significantly less friction between your hands and the barbell. Thankfully, barbell knurling helps in these situations.
Quite simply, the knurling is cut into a barbell to increase your grip on the bar. The crosshatched pattern of the knurl allows for more surface contact between your hand and the barbell. Additionally, the peaks of the knurl increase the friction between the barbell and your hands. Taken together, the barbell knurl increases your ability to hold onto the bar.
More information on increasing grip strength:
- Using thick implements and Fat Gripz in training to increase grip strength and upper body strength
- The benefits of using chalk when lifting weights
Knurling marks
Barbell knurling will have multiple “knurl marks” along the shaft. The narrow, smooth bands around the barbell’s shaft where the crosshatching has stopped are the knurl marks. Knurl marks are designed to assist with setting up your hands in lifts like the bench press, deadlift, snatch and clean.
Some barbells have dual knurling marks, like The Ohio Bar from Rogue that is highlighted above. These barbells are marketed as dual-function or multipurpose bars that can be used for powerlifting and Olympic lifting, which makes multi-purpose barbells great for home gyms.
The inner knurl marks are for powerlifting, while the outer marks assist with hand placement in Olympic lifts.
Powerlifting-specific barbells, like the Rogue Ohio Power Bar, only have one set of knurl marks that are 32” apart. Conversely, Olympic-lifting specific barbells, like the Rogue IWF Olympic Bar have singular knurl marks 36” apart.
Center Knurling – Is it Necessary?
Some barbells will include a portion of knurling at the center point of the barbell shaft. People will often suggest that a center knurl is only found on powerlifting bars or multipurpose bars. However, Olympic lifting barbells will also have a center knurling.
A center knurling is rarely found on women’s Olympic lifting barbells.
The center knurl is designed to add friction between the barbell and your shirt while squatting (back or front) and catching cleans. However, it can also scrape your chest and neck if you catch a clean wrong or the bar slips in a movement like a barbell thruster. The knurling can also be uncomfortable if you perform these lifts without a shirt on.
In the grand scheme of things, choosing a bar with or without a center knurling won’t make much of a difference. There is no difference in barbell performance or price between the un-knurled and center knurled bars, so it all comes down to personal preference and availability.
However, if you’re at the competitive level, you should probably buy a bar as close to the one you will be using in competition. In these cases, you should likely buy a barbell with a center knurling (for both powerlifting and Olympic lifting).
How a Barbell’s Knurling is Made
The knurling on a barbell is machined into the barbell’s shaft by cutting grooves into the bar in a series of parallel lines. The video below showcases this machining technique.
Uesaka, a Japanese weightlifting company, is unique in that they don’t cut into their barbells to create the knurling. Instead, they press into the bar to create the crosshatch pattern. Apparently, Uesaka’s knurl is hand pressed, which is neat. Pressing vs. cutting into a barbell doesn’t matter from a performance perspective but it is interesting that Uesaka is unique in their approach.
The series of parallel cuts into the barbell’s sleeve results in small diamond patterns on the areas of the bar that are typically held on to by lifters. The pattern looks like thousands of little pyramids jutting out of the barbell’s surface.
The machine that cuts the barbell can do so at many depths. The depth of the cuts impacts the sharpness, or aggressiveness, of the knurl – simply put how pointy the pyramid tops are. Additionally, companies may opt for more pyramids in an area.
Aggressiveness/Depth of Barbell Knurls
The aggressiveness of a barbell’s knurling is impacted by how deep it’s cut, the pattern and the bar’s finish.
Some people may automatically assume that a more aggressive knurl is better. However, the knurling on some barbells feels more like a cheese grater. A consistent, medium-aggressiveness knurl is the best option for most home gyms. This type of knurling is what is found on most mid-level barbells from reputable brands.
Competition-level deadlift bars typically have the most aggressive knurl depth. The aggressiveness is useful because lifters are performing one repetition near, or beyond, their current one rep max, so having the most grip possible is key. However, performing full workouts of multiple reps with these types of bars would chew up your hands.
On the other hand, budget bars that you might find in community recreation centres will have essentially no knurl at all. There will be a pattern on the barbell sleeve, but it will provide next to zero support for your grip.
The finish of a barbell will also impact the aggressiveness of the knurl. Stainless steel barbells will be as close to the machined knurl as you can get because there is no coating applied to the barbell sleeve. Coatings, such as chrome and cerakote, add material to the grooves machined into the barbell to create the knurl. As a result, the full depth and patterning of the knurl isn’t experienced.
All things being equal, a stainless steel barbell will have a more aggressive feel than a chrome or cerakote barbell.
Knurling Pattern
There are 3 main types of barbell knurling, defined by their shape:
- Hill
- Mountain
- Volcano
These shapes have pros and cons, but the consensus is that a volcano pattern is the optimal knurl for most people.
Hill Knurling
Hill knurling is characterized by flat-topped diamond patterns that are relatively smooth. This is the type of knurl you might find on a generic barbell at a YMCA or local rec center.
You may also find hill knurling on old barbells that haven’t been well maintained. In these cases, a mountain or volcano style knurling has essentially worn away to be flat.
This type of knurling will not provide much support for your grip.
I would not recommend buying a barbell with a hill styled knurling, except as a beater squat bar or to use in landmine attachments. Essentially, steer clear of this type of bar knurl if you will have to hold on to the shaft with any load or for any duration (unless specifically to try to train your grip strength).
Mountain Knurling
A mountain-style knurling is characterized by mountain-shaped outcroppings on the knurled area of the barbell. As the name suggests, a mountain-style knurling will have a sharp peak at the tip. The sharp tip of the pattern sticks into the skin of your hands (or shoulders for squats) and results in high friction with your hand. Unfortunately, this style of knurl can be too aggressive, particularly for high repetition training, and can shred your hands apart.
Beginners may think that this type of knurl is optimal because it feels aggressive and seems like it would help with grip. However, it is probably not necessary for most people – especially those with a garage gym.
An aggressive mountain knurling maybe be important for a high-level deadlift specific barbell, like the Kabuki PR Deadlift bar.
Volcano Knurling
A volcano knurling is the Goldilocks of the knurling types.
Rather than a sharp tip, the volcano-style knurl has an elevated, broad rim that contacts your hand. This style increases the contact area between your hand and the barbell. As a result, there is high surface friction as you hold the bar, but the bar doesn’t dig into your hand.
A couple of barbells with volcano knurling that would be great for your home gym include the Rogue Ohio Power Bar (for powerlifting) or the Ohio Bar (for Olympic lifting/Crossfit).
The Rogue Echo Bar 2.0 also has a volcano knurl and it is my #1 choice as an affordable, do-it-all home gym barbell. Read my review of the bar, here.