New Shaft Material

[eski1]

Hi

We currently make some Conveyor shafts 600mm long 25 dia in 304 St/St . The Shafts rotate back and forth & are held either end in a bearing and the load is applied in the center of shaft .
At presnt the shafts fail in the center by cracking in half .

We are looking to use a tougher grade of stainless that can cope better with the conditions mentioned . Can anyone recommend a suitable grade ?

Best regards

Chris

 

[arunmrao]

You can use 410 or 440 grades or 17/4 PH grade material

_____________________________________
"It's better to die standing than live your whole life on the knees" by Peter Mayle in his book A Good Year

 

[unclesyd]

Another good candidate is High Strength Nitronic 50.

On any shafting make sure you don't have any notches in the shaft. it needs to be smooth from bearing to bearing.

 

[arunmrao]

Perhaps you could also take a look at 202 grade material.

_____________________________________
"It's better to die standing than live your whole life on the knees" by Peter Mayle in his book A Good Year

 

[blacksmith37]

The failue sounds like fatigue; which means you need higher strength ,not toughness.
Can you get cold drawn/worked 304 (or 316 with higher cold work coefficient) ?
Can you get your shafts shot peened (cold worked surface)?
Or, as noted, various other alloys, some with a sacrifice of corrosion resistance.

 

[EdStainless]

What diameter?
If you go higher strength you might want to go to custom cold drawn tubing to reduce the amount of material. At higher strength you could use less cross section.

1. Cold drawn 304
2. Cold drawn Nitronic (219 is a good one)
3. annealed duplex stainless, good strength and toughness
4. PH stainless, 17-7, 17-4, 15-5, make sure NOT to use the highest strength condition. For good toughness use 1000 or 1050 aging.

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