A question of steel and coatings

[Andy]

soupmonger might be the one to talk to about busse knives.

[Tio Loco]

Forgive me if I overlooked its' mention, but I did not see any mention of the old
L-6 steel. I made a lot of blades from it.

Easy to temper. Takes dual temper nicely. I used to heat a copper block red hot in the forge and then rub the back of the knife on the block until the edge went to straw color and then quench in oil. I bent several trial blades 90° and back without snapping the blade. The edge cracked but the knife stayed intact. It will rust, but the higher nickel content slows it a bit compared to a lot of high carbon steels.

It used to be easy to come by as most all of the old big circular saw blades were made of L-6. Fully drawn it is a joy to work in its' dead soft mode and will get as hard and brittle as glass if you desire.

I'm know there is a lot better stuff out there nowadays but for the man that wants to make his own blades it is a good steel in my opinion.

[farid]

I think Farid uses T1, I like M42 myself.

http://www.faridknives.com/steelsused.htm

T-1 is around 10% heavier than most steels due to it's 18% (W) Tungsten. For around 40 years it was considered the best steel for cutting tools in the engineering industry, now it is very expensive to manufacture due to the price of Tungsten. It was patented by Crucible steels.

M2, M42, M7, M35 and many other steels I can mention are NO match for the
T-1’s cutting ability and wear resistance. This steel requires 2350 F to
heat-treat.


regards
Farid

[hedwa]

Hi

I have a carbon steel knife and it is prone to rusting. Is there a product which I could coat it with which would not change the thickness or colour of the knife to much (E.G clear) but would prevent rusting.

[JMS]

Hello, great summary !

My few comments below:

I mostly agree except with BM's version of ATS 34 that was in my opinion of poor consistency, from brittle to good.
There are a few missing other steels which are not bad at all and would have merited a word. Aogami, shirogami, are great, specially in sandwitches, aogami is tougher, and shirogami has a fine grain and gets a very fine edge, Yet they are steels that are left between 60 and 65 HRC (63 for shirogami). 19c27, 13c26, the new 14C28 also come to my mind as I discussed them elsewhere recently . M2 is in my experience much much better in edge holding than ATS34. I have met great D2 aking reasonably thin edges from Dozier and Queen.

Indeed the heat treat makes a whole difference, specially in some sensible very high or quite low carbon (SS or not) alloys.

As a finish, because it is hardly a coating, I like on carbon steel knives a ferric-chloride finish rubbed with 000 steel wool , as it protects from rust quite nicely, like a natural patina does.

[The General]

While hardly intended to be a comprehensive round up of steels, these are all steels and alloys I have used and own.

I can't honestly comment a great deal on materials I have not tested and tried.

Specs on paper are only part of the argument.

I am always willing to test out steels and alloys of course but seriously don't intend to invest in any of the steels you have mentioned. So I won't be adding them to the list.

[RSF]

I have a question. We all know the various steels by their american or japanese names/numbers but what about the home grown steels?

What does EN45, for example, equate to?

Also here's a stumper.

I asked for the chemical breakdown for EN45 and EN43 when I ordered a few bars last week. When it arrived the three sizes of EN45 all had different chemistry!

Why would the same steel have different ingredients/percentages for each size of stock?

I'm guessing,the blocks you ordered were cut from bigger blocks and some parts could of gone more to the bottom (or any direction,leaving you with blocks which had loss the added materials threw the going seperate ways,If you get what I mean.

What is considered the best when it come to making a nice long lasting knife?

[easy]

how about RWL34 ?

[The General]

how about RWL34 ?

This is one I can comment on as I do have a knife in this steel. Its an improved particle metallurgy version of ATS-34 or 154CM. I believe there is an American version known as CPM154. They are in my tests slight but barely noticeable improvements over the previous types. They are I guess on a production basis more consistent and have a finer grain. Either way I could not really tell any noticeable difference in the testing I did. Limited as it was. Edge retention wise, I really would struggle to blind folded tell the difference.

I am told these steels (RWL34 and CPM154) are much tougher and less prone to chipping or fracture than the previous ATS-34 and 154CM. Hence they ought to give better results in larger harder use blades.

[Rick Lowe CPM]

A T1 is a HSS - high tungsten (18%W - 4% Cr- 1%V) steel look at http://en.wikipedia.org/wiki/High_speed_steel
http://www.diehlsteel.com/t1.aspx
Used for cutting tools - mills drills etc
History http://www.ehow.com/list_6050282_pro...-t1-steel.html
Hope it helps!

[Rick Lowe CPM]

FARID
What about the CPM Rex T15 we use for aerospace broaches and hobs? http://www.crucible.com/eselector/pr...e/cpmt15t.html
12% W, 4.9%V, 4% Cr, 5%Co...... its almost like a belt busting American breakfast - carbides, carbides carbides! Underharden for toughness ,,,, what do you think?

[farid]

Hello Rick, how are you.
yes CPM Rex T15 is a great steel but my latest project that involves a high end Crucible steel are two choppers made from 12mm thick CPM REX 121, as you know very well it is the only steel Cricible has ever made that approaches around 71-72 RC.
talk later
Farid
http://www.britishblades.com/forums/...ighlight=farid

[tamoko]

Any opinion about RWL34 vs BG42?

[The General]

Any opinion about RWL34 vs BG42?

I really like BG42 and RWL34. BG42 is an improved version of ATS-34 and 154CM and its incredibly clean. My understanding was it was developed for turbine fan blades. If I were to say I could really notice a performance difference between the two steels that could not be attributed to other factors such as heat treat, blade size and geometry and importantly style and thickness. Well I would be a liar.

I have used both and both are excellent stainless steels. I think BG42 probably slightly edges ahead in performance terms. Though that is almost certainly my bias as I have a soft spot for this steel.

[tamoko]

I ask because i have read lot of posts: "BG-42 outperform ATS-34".
And ATS34/154CM very same to RWL34. So it is possibly BG-42 outperform RWL in edge performance?