Factory knew and two different angles on the edge

Discuss Spyderco's products and history.
User avatar
Evil D
Member
Posts: 27147
Joined: Sat Jun 26, 2010 9:48 pm
Location: Northern KY

Re: Factory knew and two different angles on the edge

#21

Post by Evil D »

bruckner wrote:
Sun Jul 30, 2017 11:22 pm
Thanks for your messages. I guess I'm gonna have to reprofile it a bit. I've watched some videos and apparently, a lot of those blades are like mine.
I'm surprised because I thought in the Golden place, they were sharpening the blades by robot.
Even if they are, that won't account for variances in blade grind angles. If the flat grind of the blade is off even 1 degree on one side vs the other it can result in a wider bevel, even if the angle of that bevel is exactly the same on both sides. The edge could also just be off center, where both sides are the same angle but the centerline of the edge is off to one side which also creates a wider bevel.
All SE all the time since 2017
~David
klp
Member
Posts: 4
Joined: Wed Aug 08, 2018 7:49 pm

Re: Factory knew and two different angles on the edge

#22

Post by klp »

klp wrote:
Wed Aug 08, 2018 7:59 pm
You think that's uneven, check this out! And this is after I did some grinding with a diamond rod on the short side (20 degrees is the shallowest I can go for now)

I thought I must have bought a single bevel blade on accident

boy this forum is hard to use. anways, I meant to post the other side, which literally had the smallest edge I've ever seen while still calling it an edge at all.
Didn't matter, it was still super sharp, and i just got a sharpmaker, and reground to 30 degrees with a 40 degree micro bevel and it's popping hairs all over.
User avatar
Surfingringo
Member
Posts: 5818
Joined: Sun Sep 01, 2013 2:02 pm
Location: Costa Rica

Re: Factory knew and two different angles on the edge

#23

Post by Surfingringo »

ConspicuousConsumption wrote:
Wed Aug 02, 2017 11:46 am
Jazz wrote:
ConspicuousConsumption wrote:
I'm pretty new to the nuances of blade angles. What do you hate about the 40 degree angle? And what do you prefer, or what's your ideal? Why?
40 degrees is 20 degrees each side of the blade laid at an angle to the stone. It's to shallow of an edge for nice slicing, whittling, etc. I like around 15 degrees each side, so a 30 degree edge angle. The 40 degree angle is a lot stronger, but I don't cut sheetrock, so I'm fine with what I like.
Thank you for the explanation. So basically you want a finer edge with the lower angle.
Aside from the performance gain, another advantage of a 30 degree edge is ease of sharpening. When using a tool like the Sharpmaker, you are applying a microbevel to the 30 degree edge which is WAY faster and more efficient than sharpening an entire 40 degree edge bevel.
me2
Member
Posts: 370
Joined: Sat Dec 08, 2012 11:37 am

Re: Factory knew and two different angles on the edge

#24

Post by me2 »

I have said before I'd like some knife company to sell knives with no factory edge, just skip that part and let me do it. It can't take longer to do that than it does to unscrew some of the really wonky factory edges I've had, none from Spyderco though. I rebevel basically all my knives, so for people like me, it would be a benefit.
FK
Member
Posts: 630
Joined: Fri Sep 24, 2004 10:33 am
Location: CT USA

Re: Factory knew and two different angles on the edge

#25

Post by FK »

me2,
+1 on factory no bevel or very basic rough bevel.
This is very commonly seen on high end Japanese kitchen knives, the maker expects the end user to sharpen to their own individual preferences.
Why so many go on and on about out of the box factory sharpness is beyond me,,, the original factory edge lasts only a short time in the overall life of a knife blade.

Regards,
FK
Member since Feb 17, 2001
User avatar
awa54
Member
Posts: 2685
Joined: Thu Jun 18, 2015 9:54 am
Location: Vermont, USA
Contact:

Re: Factory knew and two different angles on the edge

#26

Post by awa54 »

FK wrote:
Sat Aug 11, 2018 7:57 am
me2,
+1 on factory no bevel or very basic rough bevel.
This is very commonly seen on high end Japanese kitchen knives, the maker expects the end user to sharpen to their own individual preferences.
Why so many go on and on about out of the box factory sharpness is beyond me,,, the original factory edge lasts only a short time in the overall life of a knife blade.

Regards,
FK
Member since Feb 17, 2001

I'm always curious to know how many otherwise perfectly good knives there are out in the world that have fallen out of use once the factory edge got dull... I see this all the time in my friends and family with their kitchen knives; never sharpened after initial purchase, so that great $100+ chef knife they bought five years ago is useless for actual food prep and now lives at the back of the drawer collecting dust or even worse, is still being used with a *blunt* edge, which oten leads them to think that it's a bad knife.

Almost all traditionally hand forged Japanese woodworking and kitchen blades used to be supplied with an edge that was pretty basic, sharp for sure but not terribly refined, mostly because the outermost part of the water quenched (and sometimes un-tempered) edge was brittle and would chip out easily compared to the steel a little deeper in. Users of these cutting tools were expected to understand that this is the case, so the first thing you would do upon receiving a new chisel or nakiri is to do some light stock removal to get to the tougher steel and to apply your preffered edge profile. I'd bet that these days some of the higher end knives come with this step already done, as an accommodation to the US market where lots of high-dollar kitchen jewelry now sells to home users as well as commercial kitchens.
-David

still more knives than sharpening stones...
FK
Member
Posts: 630
Joined: Fri Sep 24, 2004 10:33 am
Location: CT USA

Re: Factory knew and two different angles on the edge

#27

Post by FK »

The problem with Japanese knives and wood working tools heat treat is not the temperature transformation in oil or warm water,,, it is from the heating to hardening temperature in the atmosphere. The carbon at transformation temperature will form what is call decarb or decarburization scale on the steel surface. The carbon combines with oxygen and is removed from the iron/carbon matrix. The lack of carbon will result in a thin layer of less than optimum carbon and a lower hardness.

It depends on the individual heat treatment time temperature transformation curve and steel used.

Without modern atmosphere furnaces, we expect to remove some of the initial steel outer layer in order to expose the well hardened steel. Some manuf. will remove the decarb layer completely and others not very well.

The tempering temperature is too low for decarb to occur, this softens the very hard "as quenched" steel and lowers the brittle tendency for chipping.

Steel heat treatment is a two step process.
1. Harden - raise temperature to transformation temperature and quench to quickly lower the temp. (water, oil or air is used depending upon alloy). This step forms the martensite structure.
2. Temper - raise temperature again to a much lower level to reduce brittle hardness to desired working levels.

Regards,
FK
Member since Feb 17, 2001
User avatar
Jazz
Member
Posts: 7678
Joined: Sun Jul 01, 2007 7:46 pm
Location: Alberta, Canada

Re: Factory knew and two different angles on the edge

#28

Post by Jazz »

Can you edit the title to “new”, not “knew”, please? It’s making me crazy. :eek:
- best wishes, Jazz.
Daveho
Member
Posts: 1260
Joined: Tue Feb 20, 2018 9:19 pm

Re: Factory knew and two different angles on the edge

#29

Post by Daveho »

Jazz wrote:
Sat Aug 11, 2018 3:28 pm
Can you edit the title to “new”, not “knew”, please? It’s making me crazy. :eek:
100% agree, I came here for videos the golden factory intentionally putting wrong angles on blades.
User avatar
DougC-3
Member
Posts: 3684
Joined: Mon Apr 22, 2013 2:22 pm
Location: Southeastern USA

Re: Factory knew and two different angles on the edge

#30

Post by DougC-3 »

Daveho wrote:
Sat Aug 11, 2018 3:41 pm
Jazz wrote:
Sat Aug 11, 2018 3:28 pm
Can you edit the title to “new”, not “knew”, please? It’s making me crazy. :eek:
100% agree, I came here for videos the golden factory intentionally putting wrong angles on blades.
Me too -- I at least considered that possibility :p
K-390 on hand: Mule Team 17, Police 4 G-10, Endela (burlap micarta), Endela backup, Endura (canvas micarta), Straight Stretch (now blade-swapped with G-10 Stretch), Delica Wharncliffe, Dragonfly Wharncliffe, & Dragonfly Wharncliffe shorty mod
Note to self: Less is more.
Post Reply