Material dimentions and the Grain direction

[Santa Fe]

The rule of thumb for me for material call out is thickness x with x length and this also translates into ST x LT x LG. Now when I order material I still have to describe which one of the last 2 dimensions is the Long Grain because I don't expect the suppliers to abide by the same rules I do and I have seen in the past that they don't.

 

Is there a document in the Aircraft industry that supports what I described above?

 

or in fact if you don't specify which one of the last two dimensions is the LG direction then the material supplier can cut the material blanks in what ever way is more convenient for them.

 

 

 

 

 

[crazy^millman]

Not that I am ware of and if you got material in cut wrong and if was not 100% detailed and labeled on your PO not much you are going to be able to do. Why we always sent along the grain direction page from the print or from the annotation set if out of MBD with our PO's from the customer. They cut it wrong they owned it not any of the companies I worked for. I caught one outfit that had a bunch of remnant they cut up and tried to pass off that we did not give them the correct information. I surprised them when I personally showed up and asked them to show me our paper work sent and acknowledged by them at receipt of the PO. I had befriended a couple of the guys who cut and handled the material and while I was waiting they told me what the company was doing. 30 minutes later they claimed to have lost the paper work and apologized and said they would replace the material at their cost. I reported them and found out they were in really bad shape. Not long after that they closed their doors.

[rrichard]

I agree, you have to make it monkey proof so you can move on with your project

[Santa Fe]

Any other thoughts or inputs on this issue, I am having problems again with my quality people rejecting material because the material supplier did not cut the long grain parallel to the third dimension on our PO even when is not clearly specified for them to do so. Our quality department assumes that the third dimension on a material call out is and shall be the Grain Direction.

 

I have tried to explain them that it does not have to be that way if we don't clearly specify it on our PO but old paradigms prevail. I just need to find an aerospace document or material supplier document to support the material call out form and fashion.

 

Please let me know if anybody as knowledge of such document.

[Müřlıń®]

When we need grain flow to be a certain way we send a pic with dim's and grain flow arrows so there can be be no mistake on the purchase order....and if there is then the material supplier has to eat it.

 

Don't assume people know your internal policies and procedures...

 

Dont use a separate attachment....put the picture right on the purchase order with specific dims and arrows marked specifically "grain flow".

 

I know of no such document.....your company must generate a specific purchase order form.

 

I am sure you have some sort of software to generate forms...

and make someone sign and date it before you pay for material.

[betts]

I feel your pain on the lack of absolute documentation but as Ron said I have never seen it either.  The only industry I have worked in that lives by SO MUCH standard aircraft procedure that isn't documented and survives on tribal knowledge.  At least that has been my experience. 

 

What I don't get is how your QA folks are being difficult, which is the way I am reading it.  The customer spec is the customer spec and you order the material based on what they tell you and inspect it the same way.  Period and of story.  Your PO must specify how you want it, even if you have a case where the customer part is not "grain direction controlled".  Then again I don't know who is writing the PO but it shouldn't be an issue for them to be on the same team and list it ST / LT / L in addition to specifying which is which in writing.