sae 770 aluminum bar stock

Hi- I need to machine new rear main bearing inserts for an engine and am looking to purchase a foot or so of sae 770 alloy aluminum bar stock or thick wall tubing 3 inches in diameter- anyone have any idea where it can be purchased from- thanks in advance- Chuck:

Its cast aluminum

5.5-7.0 Sn
.70-1.30 Cu
.70-1.30 Ni
.70 max Si
.70 max Fe
Al balance

I.E., a bearing alloy - likely bought as ingots (pigs?) by the ton for internal processing by mass producers of engine bearings.

Hhi -thanks for the reply- so you know if anyone sells it in bar stock- chuck

johnoder said:

Its cast aluminum

5.5-7.0 Sn
.70-1.30 Cu
.70-1.30 Ni
.70 max Si
.70 max Fe
Al balance

I.E., a bearing alloy - likely bought as ingots (pigs?) by the ton for internal processing by mass producers of engine bearings.

Click to expand...

Lordy, what would we do without John? Glad he's younger than me, I'm covered. Don't know what you kids will do down the road......

Chuck, just a note, just in case..... the 3 digit alloys of aluminum are cast product, the four digit are rolled in a mill.

Examples, 318 for casting pots and pans, 356 for structural, especially aircraft alloys, heat treatable to various values, T4, T5, T6 etc.

Common roll milled aluminum, 6061 and 7075.....

Note the very high tin (Sn) content in John's alloy breakdown, important for plain bearings.

Bob

thanks John for the formula- another member gave me the name of Erie Bronze who make the 850 alloy and say if i send the 770 formula they might be able to supply it- i will email the specs you gave and see what happens- thanks Chuck

thanks Bob for the info- this is new to me- everytime you get involved in some new project you discover a whole new world of information-Ive been a mechanic all my life and I never knew aluminum could be used for main and rod bearings untill I set out on a search to try to find inserts for this Offy engine im trying to bring back to life- thanks again for the help- Chuck

Chemistry was listed by an India outfit that probably would want you to buy a boat load (ingots for remelt, not bar stock).

Any non ferrous foundry could make it if they were interested enough.

That's SAE's job - writing down what things are made of so they can be duplicated. They call that STANDARDS.

But having an SAE number does not mean it is laying around for sale in the form you would like, especially for stuff with such narrow application.

I do know it is totally missing from the UNS book (Unified Numbering System, put out by SAE and ASTM), which lists just about every metal and says what it is related to and what its chemistry is and who standardized it.

850.1 / ASTM B179 is similar, and is listed in UNS.

5.5-7.0 Sn
0.7 - 1.30 Cu
0.7-1.30 Ni
0.70 max SI
0.10 max Mg
0.10 max Mn
0.20 max Ti
0.50 max Fe
remainder Al

850.1 is just a more "speced" version of 850 which has the same amounts of Cu, Ni and Sn.





John Oder

A couple catalogs back McMaster-Carr listed 850 bar stock, but not large enough diameter to make the same sort of bearings that I wanted to make.

I considered casting slugs from melted scrap pistons, as they have a silicon aluminum alloy, but could not find what the other alloying metals were, so I ended up using 3003 bar stock, which I have used before- but the crankshaft has to be built up with the wire that they use to reweld journals on diesel cranks.

Herb Kephart