Bearings vs Washers?
Bearings vs. washers has been a bit of a modern question in knives and I’m often asked about which I prefer. As a designer, I have employed both depending on the design. I can imagine that in the outset of use of bearings that they were an expensive and exclusive feature, however today we are seeing more and more budget knives, as cheap as $40 USD, featuring full ceramic bearings. Bearings have become prolific however, bushings still have their rightful place. Which do I prefer? Before I answer that question, let us dig in to the strengths and weakness of both.
Teflon Washers
Washers come in a couple of forms, primarily Teflon and Phosphor Bronze. I am not a particular fan of the Teflon option. The reason for this is more about sensation than function. Teflon is an amazing innovation and is great for a knife being used by someone who doesn’t intend to maintain and lubricate their knives. They will function without grease and the knife can be cleaned simply, without disassembly, by just running some hot water through it. However, Teflon doesn’t feel great. Somehow despite it’s non-stick nature, I feel that often knives that feature them have a stuttering quality to the action; never quite as smooth as phosphor bronze washers or bearings. With the availability of low cost bearings today, I do not see the point in investing in them going forward.
Phosphor Bronze Washers
The other form of washer is has been used in knife making for quite a long time. Phosphor bronze washers have earned their place in the knife making world after years upon years of service. Phosphor bronze washers are an alloy of copper, phosphor and tin. Known for their toughness and low coefficient of drag, they have often been the number one choice for hard-use and working knives. Why? Washers tend to have more total surface area contact with the blade and the handle than most bearings, creating a very stable platform that you can crank on with side-loads. In addition, geniuses like Chris Reeve’s Knives can cut them in to bigger sizes maximizing their contact area. While this isn’t an industry norm, it shows the potential of phosphor bronze. Washers tend to keep out dirt, liquids and anything that may deter the action and are easy to clean and re-lubricate. This allows the user to really trust that their knife will function as expected when they need it. While today this may be more psychological than reality, it is part of the larger patchwork of reasons a person will choose one knife over another.
Ball Bearings
On the other end of the spectrum we have ball bearings. Ball bearings also come in many forms these days. The balls used may be stainless steel or ceramic and the construction of the bearing itself has taken a few forms. IKBS, MRBS, and single row caged; knife makers and manufacturers now have multiple options.
I’m not sure which came first, however the most common of these systems is the single row caged bearing. You will encounter these on production knives ranging in price from $40 to $300+ USD. They are exceedingly effective and with proper lubrication will be a joy to deploy. They came in to prominence as flipper knives became more common. They allow for a very fast deployment and a smooth nearly drop-shut close in the action. However, they come with some disadvantages.
Bearings are much more sensitive to dirt than washers. I have had my the action in some of my knives slow down due to lint and dirt build-up. As such, they require grease or lube and a bit more maintenance than a knife with phosphor bronze washers.
I also feel that with the standard single row ball bearing system has a fairly small surface area of contact between the blade and handles. While I have never seen a specific failure of this part of a folding knife, it is something that I am mechanically aware of. Standard spec bearings have a 0.37in / 9.4mm outer diameter, while the balls sit on a track within that OD. This means their contact area is smaller than their 0.37in / 9.4mm diameter. For the same size washer the contact area is the full area of the diameter, simply meaning more contact surface.
This can be mitigated by other approaches. Much like Chris Reeve’s Knives, Shirogorov utilizes a larger surface area bearing system called MRBS. MRBS stands for multi-row bearing system and as the name suggests employs multiple rows of bearings to create not only a larger contact area but a smoother deployment. The cage of the MRBS, being much larger than the standard single row bearing system, resolves the aforementioned contact area issue and provides one of the smoothest actions you’ll ever experience. If I’m honest, I feel that this is one of the best solutions for bearings as you get all the benefits while the downsides have been reduced significantly.
So which do I prefer?
The honest truth is that it shifts quite a lot. I choose which system I will employ as a designer based a number of factors. First I consider the usage scenario. Will it be a hard-use knife or an office/home EDC? This directs a lot of my decision but there is a more significant factor to me. Something that goes in to my personal equation is feel. While this more of a ‘je ne said quoi’ quality, the objects we handle and use every day should have a ‘feel’ commensurate with our expectations of that object.
Bearings are a fast system to deploy and close and are suited very well for flippers as well as thinner and lighter blades. They make many knives incredibly smooth and are quite forgiving as their coefficient of drag is quite low. Now-a-days with their lower cost, they can be employed in most designs with ease and will make it more likely that your knife will have a good action. For many buyers this is of tremendous importance, they want their knives to open and close quickly and smoothly. My Monterey Bay Knives Peter Carey VLD on upgraded Skiff Workshop bearings may be the smoothest knife I currently own.
Washers are a bit slower of a system. They can be flung open quite quickly but typically they do not drop-shut quick ‘right out of the box.’ They break-in over time, getting better with use as the surface of the washer polishes against the surfaces of the blade and handles. It is not surprising that many Benchmade and Spyderco knives still employ washers in their action as a result. I tend to like washers for bigger blades. One knife that scared a lot of reviewers was the WE Knives Blocao, This lock-back knife, running on bearings, with a 4.25in blade quickly gained the nickname ‘guillotine’ because the blade would swing freely once released from the lock. Washers can help tame the inertia of a larger or heavier blade in to something that is more manageable for the user. Their ability to get better with age combined with their higher contact area and rigidity make them a win for me.
At the end of the day it’s personal preference and I can’t say one is empirically better than the other. If you want to know which I prefer that very day, just ask me what’s in my pocket, it’ll probably change tomorrow!