Thread: Material for bronze bush

Hi All,

I need to make some bronze bushes (grease lubricant). Is there any particular bronze I need to get or anything will do? Aldo the shaft is 1", lat clearance or hole should the bush be?

Thanks heaps
Jackaroo

I was told Phosphor Bronze is for bearing bushes for steel shafts and without any other guidance 1 thou clearance on diameter for each 1 inch of diameter of the shaft in the journal.

Now I have learnt that an "agricultural machine" needs much more clearance. (Dud alignment, dirt etc) plus it is easier to get together and it does not matter that there is some movement in the shaft as it rotates slowly.

Now over to real machinists but I suspect some detail on where the bearing is and what it is doing will help the knowledgeable.

The type of application would be good to know,RPM,how much interference will there be on the bush when it goes into its housing.
What is the wall thickness of the bearing.

Originally Posted by HavinaGo

I was told Phosphor Bronze is for bearing bushes for steel shafts and without any other guidance 1 thou clearance on diameter for each 1 inch of diameter of the shaft in the journal.

if I use a 1" reamer, will that do the job for the clearance?

I bought these after work today and I think they will do the job.

Originally Posted by pipeclay

The type of application would be good to know,RPM,how much interference will there be on the bush when it goes into its housing.
What is the wall thickness of the bearing.

Hi Pipeclay,

Its for the motorbike front shockers, so basically the inner rod of 1" is sliding inside the tube. The bush is 0.1" thickness, about 1-1/4 " long.

If it is a standard size it would probably be cheaper to buy the bushes as finished..

The list of sizes I have an OD of

1 1/16
1 1/8
1 13/16
1 1/4
1 3/8

In various lengths from 1" to 4" depending on size. 1 1/4 has the biggest range of lengths.

Pale green steel mudguard and stays, upside down fork stanchions, not a BSA D1-D3 Bantam is it?

For your bush to be an H7 clearance fit on a 1" shaft the hole needs to be no more than 0.021mm greater than the nominal shaft diameter. The ideal shaft fit is H6, which is no more than 0.013mm undersized from nominal. Altogether you can have a maximum clearance of 0.034mm. If your 1" reamer is in very good condition it should be OK, provided that your shaft is exactly 1" (less the allowable tolerance above). Ream at half the drilling speed and use LOTS of coolant/lubricant.

Phosphor bronze is ok for this (the OEM would have used this material) but have you thought about nylon or Tufnol? Cheaper than bronze and considerably easier to machine, plus they don't require lubricant in use. Many small Hondas use nylon bushes in their front forks.

I'm a big fan of leaded bronze, I think it's also the bushing metal you see on the racks at the bearing shops too. Here's a good comparison chart of the various alloys (chart at top of page 2)and as you can see it has good resistance to seizing and good conformability and embeddability of foreign matter like dirt.

http://www.australwright.com.au/data...20Bearings.pdf

I know it is a bit late now but this company specialises in brass/bronze products as well..

I have bought from them over the phone and have had excellent service...

Edit: Forgot the link (doh) http://www.georgeweston.com.au/

Thanks all.

Hi RC. I just checked, the OD is 1 3/16.
I bought the material from www.georgewhite.com.au (located in Clayton, Vic).

Chief Tiff: yes its a D1 BSA, I am rebuilding the motor, replacing all the rubbers, cables and bearings to get it back on road. I didnt think of Tufnol, might be a better option for this.

Ahh OK, George White and George Weston seem to operate together, when I was looking for windmill pump brass tube I originally contacted George White and they put me onto the Brisbane company that I linked to..

Originally Posted by Graziano

I'm a big fan of leaded bronze, I think it's also the bushing metal you see on the racks at the bearing shops too. Here's a good comparison chart of the various alloys (chart at top of page 2)and as you can see it has good resistance to seizing and good conformability and embeddability of foreign matter like dirt.

http://www.australwright.com.au/data...20Bearings.pdf

Leaded bronze are those used automotive con-rod bearings yeah?

Originally Posted by jackaroo

Leaded bronze are those used automotive con-rod bearings yeah?

Depends on what you want to do, most modern automotive conrods have a very thin lead based whitemetal (Clevite) on a backing shell to give the required strength as it's softer and not as wear resistant or strong as leaded bronze, but it will embed crap easier and is less prone to seizing than leaded bronze .

Whitemetal can be melted in a pot at three hundred deg C or so which allows you to re-metal and repair crank bushings such as model T car engines as well as larger machinery like really big diesels where the metal is fused to the engine block and not a drop in shell like modern engines. This is something you could never do with bronze as it melts at 1000 deg C or so. If you look at that link I posted, table 1 on page two shows that leaded bronze is stronger and handles higher temperatures but that's it.