# Princess auto bronze bearings



## Tom O (Jun 10, 2021)

So I bought these a while back I have to say I never new bronze was magnetic!


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## CalgaryPT (Jun 10, 2021)

It's not. Sometimes they mark as "bronze or oilite bushings" sintered iron bushings, which will stick to a magnet.


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## Tom O (Jun 10, 2021)

Ok I just thought it would be non magnetic just in case of any magnetic particles


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## CalgaryPT (Jun 10, 2021)

I've used those exact bushings. Pretty sure they are sintered iron which can look like bronze. i may be wrong Tom, but it seems people and companies call anything the colour bronze, "bronze bushings/bearings" these days. Kind of like people call all tissues "Kleenex." In the pic below are true bronze bushings (cannot be picked by a magnet) on the left. On the right are sintered iron and oilite bushings. Sintered iron can be picked by a magnet, but all LOOK bronze in color. The PA ones do say "bronze" but if they can be picked by a magnet they aren't.


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## Alexander (Jun 10, 2021)

I guess Power Fist has a rather loose definition of bronze.


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## francist (Jun 10, 2021)

Good grief, can’t anyone do business without lying? That’s really disappointing.


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## Alexander (Jun 10, 2021)

Not princess auto. Here is a bushing I made today. Anyone could buy them cheap but the customer needed good ones with a mill certificate so I had to machine them myself.


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## CalgaryPT (Jun 11, 2021)

Alexander said:


> Not princess auto. Here is a bushing I made today. Anyone could buy them cheap but the customer needed good ones with a mill certificate so I had to machine them myself.


Alex, what's a mill certificate? I'm assuming it is a signed doc stating the part was made by an operator with a certain (verifiable) degree of skill and within spec?


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## PeterT (Jun 11, 2021)

Several places that sell metals will provide sheets, some upon request, some always, some may charge a bit. I checked the box once & got a half inch stack of papers. Usually if its to some standard like ASTM or whatever its just the same composition information, but sometimes it states the mill/supplier it came from.


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## PeterT (Jun 11, 2021)

I think the only way the 'bronze' could hold a magnet like that is that it contains some appreciable amount of iron. It may not necessarily be deceptive, could be a dedicated running material. But maybe a bit counter intuitive. Bearing bronzes come in a multitude of flavors but predominantly copper & tin (non-magnetic) then other constituents. I've heard of manganese bronze but didn't think iron was a common ingredient. I cant seeing that being very good for running shaft fits though if its going to hang onto particles. Usually you want the magnet a distance away like the bottom of an oil sump haha

https://www.advancebronze.com/alloy-charts.php


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## Alexander (Jun 11, 2021)

It is much simpler than that. The mill certificate is a document that stays with the parts through ever step of the manufacturing process. It contains information such as; material type, tensile strength, country of origin, and what standard it was tested by.


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## Tom Kitta (Jun 11, 2021)

You need a certificate for applications where a mystery metal is not acceptable. Such as when a human life my be put in danger. 

Regular metal quick links cost like $2. Climbing ones ... made in France and stamped with strength in each axis + Petzel brand name cost at least 4x as much. 

In real life most cheap people rappelled off a thicker chain link - not stamped for climbing but I never heard of anyone ever dying. Now webbing failures on the other hand are quite common. That through is always beaten by simple human mistakes. 

Most hobby welding is just gluing some metal together with some rod. BUT there are applications where rod type needs to be known, rod that needs baking needs to be baked to get rid of water and that 70k psi needs to be maintained. Coupons may be taken to ensure welding is done properly. Filets need to be done and passes done as per book. This is why it takes so long to weld a pipeline - the spots where pipes are welded are no weaker then any other spot.


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## Johnwa (Jun 11, 2021)

The bronze wiki mentions that bronze alloys containing nickel and/or iron can be magnetic.


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## Tom Kitta (Jun 11, 2021)

It could be manganese bronze.

It could be aluminum bronze - supposedly has some iron in it. 

Maybe its just lump of steel that has paint applied? 

Best method is to get one of these guns at scrap yard and try to figure it out.


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## CalgaryPT (Jun 11, 2021)

Tom Kitta said:


> ...This is why it takes so long to weld a pipeline - the spots where pipes are welded are no weaker then any other spot.


Alberta is about to have lots of pipeline coupons to practice on.


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## Chicken lights (Jun 11, 2021)

Alexander said:


> It is much simpler than that. The mill certificate is a document that stays with the parts through ever step of the manufacturing process. It contains information such as; material type, tensile strength, country of origin, and what standard it was tested by.


Yep, I get those a lot running steel or aluminum. Basically just someone guaranteeing that what they think they are buying, is what they’re actually getting. Never really read one that close but I get the gist of it


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