Aircraft bolt material identification
 

I have some aircraft bolts that I am trying to use but I don't know what they are made out of. I figured out the last 2 digits are the diameter in 16th's and I think the letter before the last two numbers is the material. I figured out R is titanium but what is L,N,S & T. Thank you.

B30NR14
B30NL16
B30PN12
B30LT12
B30US9

Rick,if you don`t get an answer here try the `Flypast`magazine `historic aviation forum(keypublishing.com)....

Try searching for ASTM, SAE and ISO standards. If they conform to these then they will be listed. Most likely ASTM.

Yeah, that's not a numbering system I'm used to so can't help decrypt with work docs.

These bolt numbers look like they could be Boeing parts.

I do not know how to decode them.

Those numbers are not in the Boeing PSDS system (Product Standards Data System) so they are not Boeing fasteners.

And FWIW, in the Boeing system the material code is usually (but not always)
"A"=alloy or carbon steel
"C"=CRES (stainless steel)
"V"=Titanium (6AI-4V)

The other letters may indicate plating (such as cad or silver plating) and/or the type of lubricant and/or passivation.

Hope this helped.

KenV, from here they seem to be 737-300/400/500 parts.

737-300 400 500 AMM ·É»úά»¤ÊÖ²á STANDARD PRACTICES - ENGINE(47)_À¶ÌìÃñº½Íø_Ãñº½·!Òë_º½¿Õ·!Òë_·ÉÐз!Òë_Ãñº½×ÊÁÏ

They are more likely GE or SNECMA parts. I did see in another website that one of the bolts the OP listed was associated with the CF6 engine and in the link you gave the bolts are associated with the CFM56.

It might help if the OP said where he obtained the bolts and I'm curious what he intends using them for.

Rick,

They look like Boeing numbers, try searching google with adding "BAC" to the start of the part number and removing the numbers on the end, see below. Material information will be in a Boeing SRM, chapter 51-40,

BACB30NR
BACB30NL
BACB30PN
BACB30LT
BACB30US

Also google, "eng-tips.com/viewthread.cfm?qid=124385".

They look like Boeing part numbers.
You are correct that the last two digits are the diameter, they should then be followed by a dash number indicating the length.

The B30PN part number you have are probably manufactured from inconel. The engine attach bolts for the B737NG have part numbers starting with B30PN.

Rickseeman, I trust that these bolts are going to used for non aviation purposes? If for aviation do you have release documents? In any case your I.P.C. will tell you the correct part number for where you are going to use them, it should also offer any alternate part numbers.

BACB30LT - A286 CRES PER AMS 5737
BACB30NL - PH13-8Mo CRES PER AMS 5629
BACB30NR - 6Al-4V TITANIUM ALLOY PER AMS 4928 OR AMS 4967
BACB30PN - NICKEL ALLOY 718 PER AMS 5662 OR AMS 5962
BACB30US - NICKEL ALLOY 718 PER AMS 5662 OR AMS 5962

With diameter in Imperial units, the country of origin is more likely to be USA than France. For material, relative density (mass divided by volume) can give a good indication.

As noted by others, the part no. prefix used by Boeing for their standard bolts is BACB.

The OP did not mention the specific application he "was trying to use the bolts for". But normally it would not be wise to use any fasteners that you don't have traceability on for an aircraft application.

I got these bolts from a guy that parts out airplanes. They are so pretty I hate to see them get thrown away so I look for something to do with them on my farm or race cars or in the shop. The reason I was wondering about the material is I was hoping I could shorten some of them to use on my drag car but the material is so hard I will probably have to give up on that idea. Thank you for your help. And no they won't be going on airplanes.

Even for use on a race car, you should perform NDI and dimensional checks to make sure the fastener is in good condition. Unfortunately, this might cost almost as much as a new similar fastener from a commercial source. The best use for these salvaged aircraft fasteners is for restoring museum display pieces.