17-4 H1150 has a +1 coming to the party.

How can H1150 meet H1150D mechanical properties? It all depends on if the material requirements will allow the use of the material. If the desire is the mechanical properties and not there double aging, it’s possible. Here’s the quick 411 on how.

There are a few times when I am just on, ya know? Maybe it’s the 32 ounce RTIC cup that my gal Audra (shout out to that Georgia girl in Philly now!) gave to me for Christmas so that I have a continuous hug in a mug (aka coffee), perhaps the mutli vitamin that I take daily (could it possibly be), or slight chance that it’s my Spotify playlist of baller jam playing just loudly enough for me to get the good mojo going when I hear Korn’s cover of “Word Up”.

Who knows? It happens, tho.

On this particular day, while listening ever so intently on a conference call from hell of excess inventory and what can be done about it, I spoke.

Those that know me, know I speak a lot. I mean, a lot. I’m a chatty kinda gal, silence makes me uncomfortable — much like too much white space on a paper. Like, it needs to be filled. Shockingly enough tho, I have learned on conference calls and most meetings, I need to just STFU and listen.

But this time, I just couldn’t.

Next thing, I know, while the discussion is about small diameter 17-4 H1150 (what I have always known to be SH (Single H) 1150 as in not DH (Double H) 1150, I pipe up like I have something important to say.

So I said, “I can see what we can do here in the Southwest with it as many times, SH1150 will meet DH1150 properties (the mechanical testing parts — yield, hardness, etc), IF the requirement is to meet properties and not the double heat treating.”

What? Who said that? Oh dayum. I spoke in a call when I should have just been noting the activity of next steps. Next steps? Whose steppin’? Well, that would be me, when it’s all over and the fat lady starts up the pipes.

But yep, Folks. It can happen. And it does. More than you’d think.

So why is 17-4 both single aged and double aged?

Well, to get the technical of it, I had to burn a call to my go to guys at 10.5% Guroos again. (One day, I’ll ask for permissions to use their names, they are great folks there and they help me daily. I mean DAILY.)

The standards for aged hardened material is none other than our buddies, good ol’ ASTM A564, AMS 5643 Mod, Condition H1150.

Notice I just mentioned SH1150. Not DH1150.

In our oil and gas world, we live by the standard NACE MRO 1795. NACE doesn’t even MENTION SH1150. Distant relative. Double H, Folks. Because more has to be better, I guess.

NACE is the National Association of Corrosive Engineers. The big think tank of folks way smarter than I that have been looking at corrosive properties of materials and having fun doing it. These cats sit around in chat rooms several times a year, talking about things like resistance to corrosion, useful life spans of the tooling, and oh mah gah, risk mitigation from tool failure (shudder!).

Back to DH (Double H)1150.

Well, heat treating a bar of 17-4 twice will give a bar higher strength and make the material harder, because not only is more better- the twice heat treated bar will be more resistant to a corrosive environment, have a longer useful life in the tooling and will be more resistant to failure in end use application.

To get there tho, its a very tight timeline thru a flaming hot. big ass oven.

When material gets treated, it actually gets softer. No shit. It does.

Tensile is lowered because the heat treating temps are in lower ranges and the second aging is at the freaking lowest temperature possible to obtain the desired results of –

Yep. Single H properties in a Double H bar.

My go to Guys at 10.5% Guroos (nope, I’ve not asked for permissions to use names yet– yes, I should have priorities in order) have advised me that temp ranges are sorta like suggestions — as in, “Get it this hot, don’t go over, because if ya do”,… Well, you just won yourself a fairly expensive do over, ya know whaddaimean?

Here’s the mechanical deets, Peeps!

 Ten(Min) Yield (min) ElongationReduction of Area Harndness (HRC) Impact (ft lbs) 
H1150135105165028 MIN30
DH1150125105165024 Min / 33 MAX30

Remember tho —

NACE is applicable to DH1150, Double H 1150 or even H1150D. To be in compliance completely with NACE, the material does have to go thru the second aging. In the check list world of receiving — that second aging has to be on that MTR. If not, it’s a reject. There are material requirements that don’t require he second aging. One just has to read the requirement to the MTR and ask the question — Do you want properties or the extra heat?

I leave you with this — “A grill is just a source of heat. Just like a stove, it is very user-friendly.” Bobby Flay

630 is 17-4. Really. I’m not joking.

In my day, I usually have several “are you KIDDING ME” moments sprinkled heavily with eye rolls, sighs of varying audibility, with a few ermahgah’s thrown in just for giggles and grins. You get me. It helps the day go.

Some days, tho, the kidding me’s, eye rolls and ermahgah’s just aren’t enough.

There are things that pop into the ol’ email in box that just demand more, but yet, in an office, more cannot be given, ya know? Gotta stay somewhat PC, even in the oil patch. A short line requesting help on a forwarded email chain (you had to know it). Close to the end of the day (of course!) And while reading the chain a sigh with the eye roll, immediately followed by a gaze to the ceiling with a finale of “ARE YOU FREAKING KIDDING ME!?”, just doesn’t quite give the satisfaction that I need when this sort of thing happens.

I got a live one that day. A customer ordered 17-4 round bar. The Material Test Report (MTR) didn’t have 17-4 called out specifically as the material type. This particular mill calls 17-4 “Type 630”.

Our customer was just a bit short of pissed because in their mind, we shipped the wrong material and the email string was all about negligence, shock and awe, just short of amazement at the carelessness of our quality standards. As I read the email string, I could not believe what I was reading! They actually believed that Type 630 and 17-4 were two different material grades!


Google, people. The best book you’ll ever read.

So, with my eyes that couldn’t stop rolling, I call my branch and explain that as long as I’ve been in this industry, 17-4 and Type 630 have been used interchangeably for the same material. Why? I don’t know. It just is.

But the customer wants a Certificate of Compliance (C of C) from the mill (not us) stating that fact — that Type 630 is 17-4.

Oh man, you are not SERIOUS! Really? A C of C? Because, yeah. Mills want to do that.

Well, I have an ace up my sleeve because I know for a FACT that when I ask this of my mill contacts of this mill, there’s gonna be a chuckle or two as the three of us combined experience is pushing seventy five years in the industry (one of us, I think was born under a pump jack).

I call my gal, I ask her to help me with my problem and of course, she does in the best way she can. She has the UNS code, UNS17400 added to the MTR. It should by all reasoning, stop there, right?

No. No, it does not.

The customer’s interest has peaked. In a wild way. Wants to know the history of why Type 630 went to an UNS code. And when? And who or what “entity” made those changes?

Have I mentioned Google?

When one does the Google of what is Type 630, one of the first options to click is “SAE Type 630 stainless steel (more commonly known as 17-4, also known as UNS 17400 is a grade of martensitic precipitation -hardened stainless steel.” (Wikipedia).

BOOM! There ya go. Finished. Right?

No. No, we are not finished.

So I call a lifeline to my Product Manager, that is one of those kinds of product managers that has sat in a buyer’s chair for good while and has probably forgotten more than I know of stainless material.

You’re gonna love his answer.

“Just because it is.”

Thank gawd he elaborated a bit to get me out of this pickle with the customer and to share with you’s guys.

Back in the day, Society of American Engineers (SAE) used a three digit numbering system for identifying alloys. When it came to 17-4, SAE decided to use SAE Alloy 630 for 17-4.

17-4 is one of those alloys that have the ability to be heat treated in several heat tempers, such as 17-4 H1025, 17-4 H1150 and 17-4 DH1150. SAE didn’t create a unique three digit number for each of the heat treats, so the industry has used 17-4.

I leave you with this…. “I am just a child who has never grown up. I still keep asking these ‘how’ and ‘why’ questions. Occasionally, I find an answer.” Stephen Hawking