Maserin 680 Police Folding Tactical Knife Discussions | Drop

Apr 24, 2018

I wanted to discuss something in an older comment below, but didn't want this to get lost in the crappy post order thing that happens here.
RE: @MoonStanMASSDROP : the knife runs on THRUST BEARING!! Why do you fail to mention this very important point! This is an actual selling point ! I mean, bearing is already nice, but this one is no cheap IKBS or ball bearing. Thrust bearing are designed to withstand a good amount of AXIAL load , while ball bearing are not . ------------------------------
There are many types of thrust bearings. KnifeCenter shows the following pic of the bearing on the product page :

This type is nothing more than a regular caged ball bearing with grooved races to stop MINOR axial play. Something I've seen in much cheaper Chinese made knives as well.
At any rate, is a thrust bearing THAT much of a selling point? Seems like marketing to me. Assuming everything else is machined with tight tolerances, won't the pivot pin and the cutout that the bearing and race is recessed into stop any and all potential axial play anyway?
This isn't a dig at their marketing or manufacturing or anything, I'd genuinely love to hear from anyone who has actual knowledge on the topic, if this is really a perk?

Jhova90

May 5, 2019

KavikI know very little about different bearings, but these thrust bearings look identical to my knives that are spec'd with caged bearings. I didn't take any knives apart just looked at a few that I knew we're listed with caged bearings. Maybe I'm missing something, but this doesn't seem like a big deal to me and it certainly doesn't justify the cost. If Im wrong I'd love to know the difference, I'm always up to learn something new about knives.

(Edited)

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May 5, 2019

Jhova90Yeah, wish that conversation had gotten the attention of some people with actual experience on the topic, could've been interesting But, yeah, still just looks to me like standard caged bearings with grooved races, versus flat washers. A good thing, but not anything THAT special, innovating, or uncommon

Jul 3, 2019

KavikAll ball bearings are thrust bearings because they can take an axial load. Thus it is not an out of the ordinary trait of a knife with bearings. I am a mechanical engineer and thus know a thing or two about bearings. In fact you can use the terms interchangeably to describe the same bearings, thrust or bearing.

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Jul 3, 2019

Spokes30I'm not a mechanical engineer, but I've read up a little bit on bearings for different projects I've wanted to do, and I'm sure I've seen differences pointed out between thrust, linear, and radial ball bearings. That statement doesn't sound right. You do seem to back up the point I was making though; thrust bearings in a knife aren't some new innovation that will make anything here better...it's basically the same thing many companies already use as their choice of captured ball bearings...the rest is just advertising

Jul 3, 2019

KavikWell I am and have been for over 40 years. Linear bearings have nothing to do with a knife. Most of the load on the bearings in a knife are radial and the thrust capability is far behind. No human with their bear hands can come close to the failure point of any of these bearings installed in a knife even if they are thrust bearings installed. You are getting hung up on something that is a nonissue. Try crushing one bearing sometime, never mind an entire set that is in a knife. The problem with bearings is that they can get gunked up with dirt so they no longer roll in their race. Bronze bushings are tight against each other so gunk getting between the plates has a harder time getting in. Neither bearing system will ever fail due to overload just due to dirt. Plastic bushings are another story because gunk getting in can scratch the mating surfaces of the plastic.

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Jul 3, 2019

Spokes30I'm aware that linear bearings have nothing to do with this knife, i was just questioning your blanket "All ball bearings are thrust bearings" statement. Unless you meant 'All ball bearings used in folding knives are thrust bearings'? I assure you, I'm not hung up on anything (or, wasn't a year ago when I posted that). If you read back through, I was making the same point, that it's just marketing, and it's purely overkill. Of course any of these bearings, if kept properly lubed and cleaned, are more than capable of handling the relatively small stress they're put under for such short periods of time. It was just an attempt to start a conversation about pros and cons between bearing/race choices in knives. Particularly, are grooved races really necessary if the pivot pin, hole, and stops have tight tolerances? In my mind, if the pivot is tight and the bearings are the proper size (ID & OD), then there should be no fear of the bearings moving side to side on flat washers anyway, right?

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Jul 3, 2019

KavikNo knives, including this one use linear bearings. Linear bearings have no place in a knife forum discussion. Thrust bearings and radial bearings at this small size and forces are the same bearing. A typical bearing has load limits radially and axially much higher than what will be applied through any knife. Grooved or non grooved races is a non issue and should not have much bearing on the decision to purchase or not. Your knife if you use it will eventually have grooves where the bearings ride. Closed bearings may be better for a knife subjected to dirt but the negative is they are harder to clean out once dirt gets in but most importantly they would have hardened races for the balls to run in. You can get open self contained bearings with hardened races which would be much better than what is used in most knives. However, all knives have open bearings with no hardened races for what reason I do not understand, perhaps weight savings. Most important is the material that the bearings rides on which is either the liner or the scales. Bearings are about 66 Rockwell and the bearing surfaces be it titanium or stainless steel are in the 40’s, not good. The small point loads of the bearings will dig a groove into the bearing surfaces they ride on and loosen over time. For this reason I am not the biggest fan of ball bearing knives. Phosphor Bronze flat washer bearings make a whole lot more sense for a knife, especially if you use the knife. The bearing surfaces of a flat washer bearing is many fold larger than a ball bearing surface and its lack of space between bearing surfaces does not easily allow dirt in. Also as a flat washing bearing wears you simply tighten the pivot and bring the surfaces closer together so wear can be adjusted out, this cannot be done in a ball bearing pivot. In the effort to appear more technically advanced ball bearings are perceived as being better in a knife. On drive shafts on large ships bearings made out of bronze or even a very hard wood called lignun vitae is considered the best. In precision lathes the best were once poured lead bearings which are called Babbit bearings. I am shagrinned how marketing has completely brainwashed people into thinking that ball bearings are the only way to go in knives when they really are not. I will buy a bronze bearing knife any day above a ball bearing pivot knife but unfortunately they are far and few between.

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Jul 3, 2019

Spokes30"all knives have open bearings with no hardened races for what reason I do not understand" "Bearings are about 66 Rockwell and the bearing surfaces be it titanium or stainless steel are in the 40’s, not good." It's statements you make like these that I just don't understand. I'm not looking to start a bearings vs washers debate, but the "facts" you're sharing on what make bearings worse are....exaggerated at best. I have many knives that run on bearings, and even the cheap ones generally have some sort of barrier between the bearing and the handle material. Could be a flat washer, could be grooved. Sure, some of the cheapest ones use cheap/soft washers, but many are hardened. I've never Rockwell tested one, but you can tell the ones that don't wear as much with use. I don't recall if I have ever taken apart a single knife that had bearings riding directly on titanium. And it's not as if once you wear a groove in a cheaper race the knife is worn out and tossed away. Pivots can be tightened on these as well. And when you get to the point where you can no longer do that, you replace the race, not a big deal

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Jul 3, 2019

KavikGo four years to school and become an engineer. Most bearing in knives do not have races. They are retained in a cage and one side runs on whatever material is on each side of the bearing which is the hardened material of the knife and the liner or scales material. There are plenty of pictures on the internet showing this.

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Jul 3, 2019

Spokes30Lol i don't need to be an engineer to open up the knives I own and see what's inside them. Maybe SOME are that way, in which case, yes, that's poor design and is an inferior product. Definitely not "all", and I'd even gamble and say not even "most". Hence... Exaggerated. Maybe some day when I'm really bored I'll crack open all my knives that run on bearings and do a count

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Jul 3, 2019

KavikMost knives are that way. Who are you to say that I am exaggerating, how rude can one get. You keep saying you don't understand and are not an engineer but then you don't want to learn either because you seem to know it all. My guess is you are of the generation who does think they know it all when they don't and you certainly don't. It will be interesting that you can dish out the criticism and then will not be able to handle any criticism that moves the other way. You should be thanking me for the education I have given you as an engineer and instead you say I am an exaggerater. Then continue to be forever confused and you deserve to be confused because you don't want to learn. Maybe you will believe this guy more, who is not an engineer, https://www.youtube.com/watch?v=NMlpzjMtKSk.

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Jul 3, 2019

Spokes30🙄 You sure do love to be offended, don't you? LOL I'm always willing to learn, it's something I enjoy very much, and am well aware that I don't know everything, and it has nothing to do with my generation. Don't know where you're pulling that malarkey from, but i'll file it under more of your mythical "facts" I guess. Hate to burst your bubble, but in this particular case you didn't actually share anything in this conversation that I didn't already know. Who am I to say you're exaggerating? Well, um, just someone sitting here with 2 Ti/bearing knives on my desk that have races between the bearing and the handle, while reading you say "all knives have open bearings with no hardened races" I could go into the other room and pull out a dozen more that have races between the bearing and the scales/liners Just, you know, someone with common sense and two eyes. The sad part is, I know you have some knowledgeable information in that head of yours, but when you speak you wrap everything inside such absolute and extraordinary claims that any good information you share becomes suspect. And if anyone questions anything you say, you react in ways that can only be described as disproportionate or imbalanced. I don't know why I have to spell this out again for someone as smart as yourself, but here goes....*deep breath* Again: Yes, if bearings around 64hrc are riding on titanium or soft steel, that's a problem. On that we agree. No, not "all" knives do that. In MY PERSONAL EXPERIENCE not many do. See the difference there? That's what I was arguing, that you are exaggerating the scale of the issue. I wasn't questioning any of your knowledge on the mechanics involved. But you keep trying to twist it back to that, so you can validate yourself by throwing around your credentials and attempting to discredit others. I thought we were past that, but here we are again...different conversation, same old tactics 😒 Is that a "generational thing" too? Or is it rude and offensive for me to suggest that, just because you're the older of the two of us and that somehow makes it different? I'm constantly in awe of your ability to endlessly insult people while playing the victim in the same breath, so to speak

Jul 3, 2019

KavikYou are offensive and as I thought you cannot take your own medicine. Your goal is not to learn it is to aggravate and prove you are right when you admit you know nothing. Yes older people have been on this planet longer and thus have seen more things and should be respected for that and can be learned from. Also I have decades of experience in designing machinery with bearings in them, so yes I know more than you about bearings. I am sure you will find that an insult too. You are completely wrong about how bearings work in knives but because you are sensitive we are not suppose to say you are wrong but you can tell me that I am wrong and insult me at the same time. Typical. You will probably say the older guy in the Youtube video is wrong too because he has gray hair and says exactly what I say. I will not longer waste my time with your type because you know it all anyway so why bother.

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Jul 3, 2019

Spokes30LMAO can I let you in on a little secret? I've got greys too 🤫 I don't know who you think I am, or how old you think I am, but you've got me completely wrong. Some of my most memorable teachers throughout my life have been old as dirt, and I respected the hell out of them. I don't care about your age, I only brought that up to point out that you're being just as offensive when you do that to everyone. I respect those who deserve my respect, not those who disrespect me over and over. Once again you've misinterpretted and/or ignored everything I said. Before you run off, I'd love to know specifically what I said about "how bearings work" that I was "completely wrong about", if you would be so kind?

Jul 3, 2019

KavikYou are completely wrong by stating that most knives have a hardened race and the sides of the knife do not act as a race. For most knives that is the setup if you like it or not. Maybe you only have expensive better built knives. Shame on you for insulting me for simply explaining to you how most knife bearings work. I guess you have learned from younger people how to insult. I would hope you watch the YouTube I sent because it very clearly explains exactly what I have explained. There are pictures of this setup all over the internet too. Read through your emails which essentially say I do not understand how bearings work in a knife and then when told by me you disagree. Thus why do you ask in the first place if you already know? Ball bearings in a knife is a marketing thing and not the best choice technically for the reasons given. Large area phosphor bronze washers is a much better system for a knife because you don't have a point load of hardened steel against a much softer material like titanium or unhardened stainless.

(Edited)

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Jul 3, 2019

Spokes30One addition, the ideal setup for ball bearings would be to have hardened discs on the outside of each bearing press fit into the scales or liner. However, this is complex, it takes up thickness space and costs more to precision machine the countersinks for an interference fit for the hardened discs. Some higher end knife makers do this but I have never seen it because I do not buy expensive enough knives. Another thing you are wrong on is you cannot keep tightening a pivot on a ball bearing knife and hope it takes the play out as you can on a bronze bearing. It will eventually force the balls out of the retainer cage which is usually placed into a machined and thus fixed position countersink. Ball bearing pivots have an end life, bronze bearings if lubricated will last many lifetimes. However, if you never use your knife with force, except to open and close it, ball bearings will last a long time.

(Edited)

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Jul 3, 2019

Spokes30A) saying "most knives be a hardened race" is not a statement about "how bearings work" B) that's not quit quite what I said And C) I was VERY clear in pointing out that the statements I made were in relation to my personal experience with the knives I own, specifically in relation to the amount that have races/washers vs those that don't. While you continue to make broad generalizations about all knives out there in the world. If you can't see the difference in the points I'm making by now, you never will

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Jul 3, 2019

KavikYou have made broad statements that all knives that have ball bearing pivots have hardened races and that is simply not true. The vast majority of folder knives sold on this site and by most knife dealers do not have hardened races. Maybe yours do because you buy better knives. You wanted to know how this ballbearing in knives work and I told you, most don't have races. You do not acknowledge the video I gave you because it disagrees with your comments and agrees with what I have said. Your interest is to be correct at all costs and not to understand the facts. Again why do you ask if you already know and in your last email you said again you know it all? I have the ability if I am wrong to say I am wrong and have learned something, apparently you do not have that capability. I think you should stop calling a black kettle black. There is nothing more to say on this subject because it is moving away from the technical question to one of social etiquette.

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Jul 3, 2019

Spokes30Lmao okay, i guess it's pretty clear now it's a matter of reading comprehension.....because I never said that (unless it's delusion... 🤔) I didn't comment on the YouTube video because I haven't watched it yet. It was provided as backup to an argument you think i was making, but wasn't. Anyway, this has become absurd. Have yourself a nice day

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