Spydiechef steel or ceramic detent ball, which one is smothest?

sogflash

sogflash

Joined
Aug 28, 2011
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I have two Spydiechefs. One of the first type with matte gray hardware and a steel detent ball, and one of the newer CQI type with black hardware and a ceramic detent ball if I'm not mistaken. I noticed one opened significantly smoother than the other.

Which of the detent balls would give the smoothest opening if everything else is the same? All the other things aren't the same because one is a user with the blade reground to get a pointier tip, and the other is still brand new.

There are so many other variables at play here. How worn in it is, lubricant, how dirty and gritty it is, how tight the pivot screw is, the few grams of blade that's ground off. Maybe the lock bar tension is slightly different.
I'm just wondering if ceramic and steel detent balls give different levels of smoothness in opening.

What are the pros and cons of ceramic and steel detent balls? The ceramic ball wont rust, but are there any other advantages or disadvantages?
 
I have a CQI 1 version: ceramic detent and gray hardware.

It is really quite smooth.

I think the main difference with the ceramic ball is corrosion resistance. Sure, there is probably a difference in the coefficient of friction, but I suspect the surface area involved is so small that any perceived difference is negligible, especially when compared to other factors like lockbar tension, pivot tightness, etc.
 
With ceramic detent balls I disassemble the knife and give it a few swipes on a leather strop with green polishing compound. That will polish the ceramic to a glass smooth finish.
 
From a material science perspective, steel does deform a tiny, microscopic amount under forces like the pressure on a detent.
Ceramic, being locked in ionic bonds, doesn't deform at all (in theory, at least).

From an engineering perspective, deformation of a round object causes normal forces that increase resistance to movement.

A known coefficient of friction in these two different cases would immediately yield an answer, but I can't find those numbers, or numbers precise enough to make a reasonable assumption. However, my intuition tells me that the steel ball probably has a higher coefficient of friction (due to reasons above), and therefore causes more resistance.

But realistically, I doubt the different detent balls are enough to make a noticible difference in action; at least, not more so than other factors like lockbar strength variances, washer surface quality, etc.
 
It would be interesting to find out the why of the change, I would suspect corrosion resistance except with the modern stainless it isn't a problem(surgical, food industry etc). Its usually money or to fix a defect that changes are made. Industrial hard chrome is 66-70 HRC.
 
Steel detent balls wear/deform noticeably. I do not have the said knife but have seen a flat top on many detent balls on other knives. Not sure what steels those detent balls are made of but are they usually softer than the blade steels like K390, 20CV etc? As the detent ball constantly glides over the blade tang, it seems to me wearing is a more sound reason than corrosion of picking ceramic balls over steel balls.

On a side note, do any knife makers/craftsmen replace detent balls?
 
Some people with LC200N mule knives were finding them rusting from their handle hardware.

I think it was a preventative measure to avoid the blade being contaminated and then reacting.
 
A ceramic detent ball is off course a pretty nice uppgrade. They basically dont wear out. A steel one, as tiny as it is, will have a pretty rough time gliding along the tang surface over and over again as time goes by.

Ceramic detent balls should be mandatory IMO.
 
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