Maching Bar Stock Fittings

[ContractHome]

If Astm B366 -S5.1 is required by the end user, then what is the concern:

Does this include both boring the I.D. and turning the O.D., or is maching prohibited with no exception?

What is the concern in fitting machined from bar stock and how does it differ from which are forged?

 

[EdStainless]

normal bar stock will have some pipe or stringers running down the length of the ID. If you try to make an elbow or angle pattern valve the odds are that you will get leaks.
Often the reductions in rolling of bar stock are small and don't result in 'forging' the material. There is also no cross flow in rolling.
Forging will break up stringers and assure that you have sound metal.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

 

[moltenmetal]

Some standards permit the use of bar within certain size limits without restriction. Beyond that size, you are required to do rigorous flaw detection on the bar prior to machining, and to do mechanical testing in both the radial and axial directions.

Having the grain flow in the right directions is desirable, especially for tees, elbows and flanges, but the minimum necessary criterion is that the material be of adequate homogeneous strength and without flaws.

As has already been noted, bar is commonly used for small fittings which suit round stock such as socket welding reducer inserts and swage nipples (the latter if you're foolish enough to specify them). Rather than stocking a myriad of sizes in umpteen materials, many local distributors stock bar and work with a machine shop to produce the required parts on a ~3 day turnaround. Saves them a bundle in otherwise dead inventory.