Cast Alum Substitute from NACO 150 1

[VaBeachZ]

I have two Norwegian items cast from NACO 150 Alum (Nordisk Alum Co.), circa 1971. American sub given is SAE 309.

We have no molds to remake just one of each part. I'm looking for an extruded substitute alum alloy for the cast alum material and make billet from a block about the size of a 3 lb. coffee can.

This would be the easiest route because of reduced paperwork and recertification, i.e., a direct replacement material. If items were made from sheet alum and welded together, recertification would be in the process again.

Thank you for reading and your suggestions.

Everett#2390

 

[swall]

The old SAE 309 is the current 360 die cast alloy. 6061-T6 wrought alloy should be an acceptable substitue.

 

[VaBeachZ]

Thanks for the info!!

Documentation wise, how would I get there?

There are no problems, just challenges. Everett#2390

 

[swall]

Assuming that your customer will let you make the substitution, the biggest source of misunderstanding that may arise will be with the mechanical properties. The published properties for die castings are "typical values", not guaranteed minimums. For 360 alloy, the UTS is 45 ksi and the TYS is 24ksi. For 6061-T6 extruded aluminum, the published mech properties are minimums and these are 38ksi UTS and 35ksi TYS. Rule of thumb for die castings is to design to 80% of the published typical values. Thus 80% of 45ksi is 36ksi and the 6061-T6 min UTS is slightly higher than this.

 

[VaBeachZ]

Thanks, Swall! I'll use this info to present to the customer.

There are no problems, just challenges. Everett#2390