Developing Methods For Knife Testing

[Vivi]

I'm trying to figure out ways to make my reviews more objectively valuable rather than filled mostly with things like "It's a comfortable knife and has a nice blade shape." Ways to standardize out of box sharpness rather than saying it's hair popping sharp, etc. I'm also looking for suggestions as to what information should be included.

Here are some of my ideas for information to make sure I include in future reviews

-Standardized out of box sharpness testing
-Measure the force needed to make a cut with the factory edge profile versus a more acute edge ground on later
-Edge retention testing against knives with similar edge profiles using materials where blade geometry behind the edge has the least influence possible. It would be interesting to run multiple retention tests, one with a highly polished profile edge and another with a coarse edge, and test both in push cutting and slicing to see how they compare in areas they're known to excel.
-Note the balance point of the knife
-Note carry comfort in front and back pocket not clipped, and clipped to the pockets and waistband in various places while sitting, standing, running etc.
-Check grip security during stabs and aggressive slicing with gloves on, with wet hands, with hands numb from cold etc. Check ease of opening and lock operation in a similar manner.
-Test the lock in a variety of ways applicable to the lock type.
-Use the knife for all of my usual needs and note how it preforms with everyday work.
-Update the reviews after carrying the knife over a period of months / years and note if impressions have changed.
-Include large, well-focused pictures detailing key areas of the knife such as lock, grip, handle texture etc.

If you can come up with more ideas, let me know. I'm trying to build up content while also keeping out what isn't needed.

I'm still devising methods to test sharpness and edge retention. It's hard to find a lot of cardboard of the same type and using different thicknesses would just introduce another variable. I'm probably going to end up using thick rope for the slicing tests. For the sharpness testing I saw a setup on www.culteryscience.com I intend to duplicate and try out, assuming my scale with a max load of 400g is sufficient. Here's the photo: http://img149.imageshack.us/img149/2734/p10104220xi.jpg

If anyone has other ideas for testing knife blades let me know. I want to provide accurate, useful information.

 

[Confederate]

These are all exceptional goals. Given the steel snobbery most of us have, I'd be anxious to find out when a blade reaches the point of diminishing marginal return in the categories of 1) strength and 2) edge retention. I think also it would be great to test the hardness of random samples within a certain type of steel. One knife company has a tolerance of between RC57 and RC59 for its AUS8 blades, for example. But users are often plagued with doubts about what they're getting or, more specifically, what they're not getting. Looking at steel charts is a good place to begin, but it's far from being conclusive. This is one reason why I don't subscribe to knife magazines. They'll run a two-page color spread of a knife, then spend half a page describing it. The bottom line is that unless a user is buying a knife from a well known custom maker, he had no idea of heat treatment or anything else.

 

[spikedog]

I worked as a test engineer for over 10 years. Many standardized test methods are published by organizations such as ASTM, ISO, AAMI, and most test methods that I developed referenced standardized methods. The standard test methods are developed by committees of professionals knowledgeable about the particular subject and are thus accepted industry-wide. Having said this, I suspect there are standardized internal methods that the manufacturers perform (at least hardness); however, there seems to be no standardized tests for actual use as others have mentioned.

I too wish there were some standardized test, especially when people begin to "whack" the spines of knives and describe lock failure.

Someone form a committee, define the measured quantities (blade play, sharpness, killing ability, or whatever), design the test methods (i.e. how to actually repeatably do the measurement), and agree that these are the tests.

Quite a bit of work, I know, I've done it.