|12 forum posts|
Was going to order some bronze for making bushes. Where's the best(cheapest) bit to buy it? Is there much difference between the two? Advantages etc. Been looking on the local site and they have phosphor bronze grade saw-660,lg2 & rh7 doesn't mean much to me.
|Andrew Johnston||30/07/2017 17:38:29|
5115 forum posts
Oilite is a porous bronze, impregnated with oil. It tends to be used at the size as purchased. Machining can be difficult as it is all too easy to close the pores, thereby rendering the bearing properties useless
SAE660 is a leaded bronze, easy to machine and fine for bearings. LG2 is a leaded gunmetal bronze, ie, contains zinc as well as tin as one of the alloying constituents. I don't know what RH7 means. By far and away the most common bronze is PB102; that will be fine for bushes and bearings.
|duncan webster||30/07/2017 18:51:46|
2341 forum posts
Drawn PB102 is a pig to drill, I've even tried annealing it to no avail. It closes up on the drill, gets very hot, and then siezes. If anyone has a solution speak now or forever.............
Edited By duncan webster on 30/07/2017 18:52:11
|mike T||30/07/2017 19:05:39|
|170 forum posts|
Best to restrict your use of phosphor bronze PB 102 to boiler fittings rather than for making bearings. The leaded bronzes SAE660 and gunmetal LG2 are so much easier to machine and are intended as bearing materials. Oilite is also good, provided the shaft fits without the need to adjust the bore of the oilite bush.
|451 forum posts|
I have just fitted "Oilite" bushes to my Super Seven countershaft, and had to ream them to size. The "Olite" website says they may be reamed with a sharp reamer.
|Will Bells||30/07/2017 19:22:40|
|152 forum posts|
You probably already know that the classic solution to machine PB102 without tears is to use a top quality drill (I hesitate to say, but not FE), coolant and take it easy. I did use some for a fishing reel that I made and had no problems (used 4 facet TIN coated Dormer drills).
But perhaps using Calphos 90 would be a good solution. Reasonable properties and excellent to machine, although a bit expensive. I got some from Noggin End a couple of years ago; not a great selection of sizes, but was OK for my needs and machined perfectly.
Cheers - Will
|Nigel McBurney 1||30/07/2017 20:17:45|
641 forum posts
Drawn phosphor bronze can be evil stuff to machine,to stop drills binding grind the drill point slightly off centre,its a bit crude but it works, obviously drill the hole with a undersize 'off centre' drill,then finish with a ordinary drill or reamer.
|Brian H||30/07/2017 20:23:22|
1394 forum posts
By coincidence, I have just machined a couple of traction engine cylinders from PB102, simply because I found a piece that was just right in my scrap box. I drilled it through 3/4" without any problems, then bored to near size followed by reaming. The reamer has seen better days but with a touch-up with a diamond file worked well enough. I shall hone the bores but not until the cylinders have been silver soldered to the stands that hold them to the boiler and the valve chest.
I thought that the metal was being hard to work but then realised that the reamer was starting to cut the inside of the morse taper in the lathe spindle! No serious harm done fortunately but just goes to show that you need to keep your wits about you at all times.
|Andrew Johnston||30/07/2017 21:35:44|
5115 forum posts
So is PB102; according to the commercial stockists?
|Andrew Johnston||30/07/2017 21:40:53|
5115 forum posts
I've not had any problems using Dormer A002 drills, except for snatching on breakthrough as per most bronzes and brasses. I'm slowly building up a set of slow helix drills and these seem to work fine on PB102. On the lathe I always use flood coolant when drilling.
On t'other hand reaming can be a bit of an issue. Bronze and brass seem to sometimes close up slightly leaving the hole undersize. It's only a few tenths at most, and not an issue if using cold drawn stock as the shaft. But it's a PITA if you've ground a special shaft only to find it too tight.
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