Outer Limits 4x4 Board

just wondering, considering hytuf (hytuff) is just a common name, and mal tells me the hytuff he uses was an "australian recipe" would the two be the same or mabe slightly different(us gallon, imperial gallon?). just because alot are sold on an idea doesn't make it optimal.
every carpenter in oz loves steel handled estwings!
serg

popeye wrote:
if it's in stock i can get an offcut (maby) of v136 (bohlers hytuff) pretty easy, but it will be in the normalised / annealed state.

It would be great is you can get hold of some and send it to me. If this is going to happen it would also make sense to image some other steels at the same time, like 4340, for comparison. But I should be able to get some of that (or the german equivalent) here.

uninformed wrote:just wondering, considering hytuf (hytuff) is just a common name, and mal tells me the hytuff he uses was an "australian recipe" would the two be the same or mabe slightly different(us gallon, imperial gallon?). just because alot are sold on an idea doesn't make it optimal.
every carpenter in oz loves steel handled estwings!
serg

HYTUFF is the common name for AMS6418, which is a US military steel specification. However, there may be some differences depending on where it is manufactured. 4340 for instance has two different numbers under the german grading system, and the properties listed by timken steels (US) for their 4340 seem to be superior to the properties listed by OZ manufacturers for 4340.

From memory, the mechanical properties for AMS6418 given in the mil 5 handbook are nowhere near as good as those given by Comsteel for their hytuf.

Bush65 wrote:From memory, the mechanical properties for AMS6418 given in the mil 5 handbook are nowhere near as good as those given by Comsteel for their hytuf.

John, do you have the comsteel specs and composition? Here is the data from Timken.

http://www.timken.com/timken_ols/steel/ ... pdm012.asp

and see S-7108 (8th from top) - suposedly equivalent to AMS 6418.
http://www.timken.com/timken_ols/steel/ ... pdm011.asp

Strength and performance...

This is the data for "HY-TUFF", which is said to be equivalent to AMS 6425 and S-7108

http://www.timken.com/products/specialt ... HY-TUF.pdf

Ben,

From Comsteel info for Hy-Tuf:
Related Specifications AMS6418
0.25% C, 1.30% Mn, 1.80% Ni, 0.35% Cr, 0.40% Mo, 1.50% Si
Tensile strength 1500 - 1650 MPa

From MMPDS-01, which replaced Mil handbook 5

Hi-Tuf, specification AMS6425 (not AMS6481!!)
Tensile strength 220 ksi (1517 MPa)

This is similar to what Comsteel say, but I still have the belief that when I looked in the old mil hdbk 5, they a considerably lower tensile strength for AMS6481. I dont have a copy of this handbook now to check (I guess I could download it).

The more I think about this, I may not have converted from ksi to MPa, but just compared the tensile strength to that for 4340 in an adjacent column (260 ksi), but reading the notes, values for 4340 are applicable to "consumable-electrode vacuum-melted material only".

The other curious thing is that MMPDS-01 does not appear to have anything on AMS6481, whereas I was sure it was in mil hdbk 5.

BTW:
MMPDS-01 is the only source for for material strength properties and design values that the US FAA generally accepts for complience with Federal Aviation Regulations.

AMS is the abreviation for Aerospace Material Specification

MMPDS-01 can readily be downloaded in pdf format from a lot of places, but is over 70 MB. Official site for mil handbooks is http://assist.daps.dla.mil/online/start/ You have to register first at this site.