What material is it

[martin perman 1Participant @martinperman1]

Gentlemen,

I am machining a brass like material but I'm certain it isnt brass because when I've machined brass in the past it comes off in small needle like swarf where as this comes off in streams of swarf like steel and anything larger than a 0.5mm the lathe groans greatly,

Any Ideas please.

Martin P

[martin perman 1Participant @martinperman1]

[davebParticipant @daveb17630]

There are different grades of brass, some alloys are hard, some are ductile. It could be bronze. There are different grades of bronze. Sometimes difficult to tell one from the other. Daveb

[colin hawesParticipant @colinhawes85982]

Aluminium bronze, horrible stuff to drill. Colin

[I.M. OUTAHEREParticipant @i-m-outahere]

I know the brass they make amunition out of is gummy stuff so you may have a grade of brass that is designed for forming .

[JohnFParticipant @johnf59703]

Plus 1 for Aluminium Bronze machined a lot of this in the past and as Colin also say’s it’s difficult to drill, grabs the drill if you are not careful. One other point don’t use it as a bearing material (bushes) it is totally unsuitable— I know this from experience with a small engine I was repairing many years ago.

Edited By JohnF on 16/12/2018 10:22:30

[martin perman 1Participant @martinperman1]

Thanks gentlemen, I'm making four 75mm dia rollers for a mates butter churn, to support the drum and decorative only.

Its a bugger to cut on my band saw also.

Martin P

[vintage engineerParticipant @vintageengineer]

Ali-bronze! It's s**t!

Edited By Neil Wyatt on 16/12/2018 13:05:19

[not done it yetParticipant @notdoneityet]

Look up ‘copper alloys’ on Wiki and take your pick!

[colin branniganParticipant @colinbrannigan54160]

Ali bronze is worse than s**t!!

Edited By Neil Wyatt on 16/12/2018 13:05:29

[I.M. OUTAHEREParticipant @i-m-outahere]

What tool geometry are you using ?

[Nicholas FarrParticipant @nicholasfarr14254]

Posted by vintage engineer on 16/12/2018 10:54:10:

Ali-bronze! It's s**t!

Hi, sorry, but I beg to differ.

Regards Nick.

Edited By Neil Wyatt on 16/12/2018 13:05:38

[Neil WyattModerator @neilwyatt]

Mind yer language please folks!

The only sticky brown stuff on this forum comes from trees

Neil

[martin perman 1Participant @martinperman1]

Posted by colin hawes on 16/12/2018 09:56:47:

Aluminium bronze, horrible stuff to drill. Colin

I would beg to differ, I've just given up trying to drill a hole through a slice I cut off, its wearing out brand new drills without hardly making a cut, the drill just polishes the metal.

My mate is going to have to find a different lump of brass or go back to plan A and use steel. I've just done a test on a lump of brass I have on my saw, the un machinable lump 95mm dia took three hours to cut a slice, my piece is 65mm and the saw was half way through in no time at all with the same blade.

Martin P

[not done it yetParticipant @notdoneityet]

Posted by colin hawes on 16/12/2018 09:56:47:

Aluminium bronze, horrible stuff to drill. Colin

I hope it is not difficult. I had a casting made by my local foundry some years ago. It turned very nicely and I have about 40 small holes to drill very accurately (to make an exact copy of an original part) and some of them will need tapping and countersinking.

[Alan Johnson 7Participant @alanjohnson7]

Have you tested your "brass" with a magnet? Some bonze has an iron content, and therefore magnetic. It may narrow your search.

You could do the Archimedes Test…… Place sample in water, measure displacement, and weigh sample. Again it could narrow your search.

[Alan Johnson 7Participant @alanjohnson7]

I should have added.. Archimedes Test will yield Kg per cubic metre. Known bronze and brass list this.

[colin branniganParticipant @colinbrannigan54160]

Sorry Neil

[not done it yetParticipant @notdoneityet]

Posted by Alan Johnson 7 on 16/12/2018 16:53:11:

Have you tested your "brass" with a magnet? Some bonze has an iron content, and therefore magnetic. It may narrow your search.

You could do the Archimedes Test…… Place sample in water, measure displacement, and weigh sample. Again it could narrow your search.

I would not expect a simple ‘Archimedes test’ would do more than reject the extremes of density, particularly if other elements are present.

Might just as well weigh in air and water to calculate, unless of very uniform and measurable dimensions when the volume could be accurately assesed. For decently accurate results, I would be using the turnings/chips and an SG bottle, along with an assay balance…

Possibly a phosphor bronze?

[Neil WyattModerator @neilwyatt]

Aluminium and copper make some interesting alloys.

Small amount of copper in aluminium is pretty much duralumin.

Small amount of aluminium in copper is aluminium bronze, but the more ally added, the harder it gets. By around 50:50 you get a grey alloy that shatters if you hit it with a hammer.

Hard to machine aluminium bronzes may have more aluminium than intended.

Neil

P.S. at our astro club Christmas quiz a question was 'what metals make Bronze'. It was tempting to answer copper and anything other than zinc, except when it's got zinc in it…

[JohnFParticipant @johnf59703]

Martin, as Neil says aluminium bronze comes in different alloys, it is difficult to machine but certainly not impossible and it is also highly corrosion resistant. The components I was machining many years ago were for submarine seawater services [corrosion resistant ] and were for want of a better description "very large plumbing fittings" pipe diameters of 6 to 12 inches, large flange's on castings to be machined then drilled and tapped or drilled and spot faced. The factory also produced other components from bar stock.

Sharp HSS tools are the order of the day and increase the top rake a little, for drilling, thin the point to ease the process and grind VERY slightly offset so it cuts slightly oversize — do not alter the flute rake as for brass. The best cutting medium is suds, it can generate a lot of heat when cutting. Your tools must be sharp !

I have machined this material successfully on my Myford with correctly ground tools etc.

John

[HopperParticipant @hopper]

Posted by martin perman on 16/12/2018 13:47:24:

 

… I've just given up trying to drill a hole through a slice I cut off, its wearing out brand new drills without hardly making a cut, the drill just polishes the metal.

…

Did you try slowing the spindle speed way down? And drilling a small pilot hole first?

If so, you may need to anneal the bronze before trying to cut or machine it.

Edited By Hopper on 17/12/2018 03:03:50

[martin perman 1Participant @martinperman1]

Gentlemen,

I'm doing this as a favour for a friend and its costing me money, three worn out and broken bandsaw blades, and time trying to machine, for me, the impossible. I dont have or use HSS tooling.

I've now asked my friend to source some different material.

Martin P

[Brian HParticipant @brianh50089]

Another way to identify it is to try and silver solder it. If it's ali-bronze, it won't.

Don't ask me how I know!

Brian

[Nicholas FarrParticipant @nicholasfarr14254]

Posted by Brian H on 17/12/2018 08:33:11:

Another way to identify it is to try and silver solder it. If it's ali-bronze, it won't.

Don't ask me how I know!

Brian

Hi Brian, I don't quite agree with you, below is a photo of a Ali-Bronze block Silver soldered to a Brass plate, that I did about 30 years ago. I don't know the grade of the Ali-Bronze, but I do know it is Ali-Bronze, it was hacksawed, filed and drilled from a worn out Ali-Bronze nut.

Regards Nick.

Edited By Nicholas Farr on 17/12/2018 09:26:53

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