MIL-H-6875
MIL-H-6875
(OP)
I searched here under FAQ's, Forums, and Links with no results.
As I recall, this specification covers most categories of heat treatment for steel but I think it has been superceded by another spec e.g. AMS...?
I am advising a friend to Normalize a 4130 weldment for an experimental airplane and will recommend he specify it to be Normalized per MIL-H-6875 or the currently applicable spec if someone can tell me the current specification designation.
Thanks in advance for help
As I recall, this specification covers most categories of heat treatment for steel but I think it has been superceded by another spec e.g. AMS...?
I am advising a friend to Normalize a 4130 weldment for an experimental airplane and will recommend he specify it to be Normalized per MIL-H-6875 or the currently applicable spec if someone can tell me the current specification designation.
Thanks in advance for help





RE: MIL-H-6875
I don't deal with 4130 weldments, so I am really just looking for information.
rp
RE: MIL-H-6875
One of the reasons to specify 6875 is for control of decarb.
I would expect toughness to be better for normalize than stress relief since again the structure will be more homogenous. Normalized 4130 is used extensively for aircraft parts and the properties are well established.
RE: MIL-H-6875
In some cases, unless using inert or protective atmosphere or vacuum, the spec. for raw materials requires removal of a surface layer of material.
RE: MIL-H-6875
ht