stainless or bronze?
stainless or bronze?
(OP)
Hi
I have a request to make shaft adapters for a speed reducer.
Theses are in a salt H2O area.ie salt water may come in direct contact.The gear boxes are made of AL with a female stainless input.The staft that is going into the gear box is stainless.Gear boxes have a 1" bore and the shafts are 20mm.So the adapters will be 1" by 20mm by 4" long.
Would stainless be better than 660 bearing bronze.have to make several and guy wants price and advice on both.
Any help would be great
eddie
I have a request to make shaft adapters for a speed reducer.
Theses are in a salt H2O area.ie salt water may come in direct contact.The gear boxes are made of AL with a female stainless input.The staft that is going into the gear box is stainless.Gear boxes have a 1" bore and the shafts are 20mm.So the adapters will be 1" by 20mm by 4" long.
Would stainless be better than 660 bearing bronze.have to make several and guy wants price and advice on both.
Any help would be great
eddie





RE: stainless or bronze?
First choice would be Nitronic 50.
Second would be 17/4 PH S/S (H1150)
Last would be 316 S/S
Monel 400 would work.
If you have to stay with bronze go to silicon bronze
316 is going to be quickest and least expensive. But if there is any load you have the possibility of cracking in the long run.
If you are around saltwater the top choices are boat shafting materials used in salt water and are very good.
RE: stainless or bronze?
RE: stainless or bronze?
RE: stainless or bronze?
RE: stainless or bronze?
Thanks for the advice on 303SS in salt spray- not my personal experience (yet!), but I trust yours. Better to learn from someone else's failures than to wait for your own to happen!
RE: stainless or bronze?
RE: stainless or bronze?
I can see that 303 is inferior to 316, but are you implying that 303 is worse in salt water than 304? I calculate the pitting resistance equivalence index for 304 to be ~ 18 and for 303 to be ~20, and for 316SS ~24. The 303 has small amounts of sulphur and phosphorus added- do these have an overwhelming influence on the corrosion of this alloy?
RE: stainless or bronze?
The answer to your question is "YES". In terms of corrosion resistance, 303 has ENORMOUS amounts of S, not small amounts. Member mcguire has posted previously on how much pitting resistance is reduced by S. Check his FAQ.
RE: stainless or bronze?
I've never seen any correlation with the "pitting resistance" and actual behavior in sea water. 303 S/S normally becomes a rust ball with deep pits in a very short time. 304 S/S starts out very slowly as very small pits that take a long time to completely cover a part in rust. 316 S/S takes a very long time to initiate pitting and is very easily cleaned. 316 S/S is usually the preferred material if you can’t go to other materials. This is because of cost and availability.
In giving a suggestion for material for use in salt water I always like to give a choice and let the cost and availability dictate the end product. Like if you were in my area all of these materials would be readily available at reasonable cost.
I opted for a stronger material as his sleeve will be fairly thin. It just so happens that the material is much better in salt water. But you can use any of my suggestons.
RE: stainless or bronze?