So has anyone taken some bronze stock to a lathe and made a pin punch? I am planning on doing this because I deal with a lot of roll pins, large ones too, around 3/4 to 7/8, and I was just curious if anyone knew a good grade of bronze to use for a punch, from what I understand bushing bronze is too soft, more like brass, any suggestions?
Making bronze punch
- Thread starter Tom.C
- Start date
afazz
Well-known member
I can't answer your question on grade, but here is some inspiration. I inherited a bunch of brass rods when my grandfather passed, and I turned them into punches.
I ended up with more than I needed, so I gave some to a buddy who works as a die maker. He made some little brass hammers from large punches and a piece of brass.
I ended up with more than I needed, so I gave some to a buddy who works as a die maker. He made some little brass hammers from large punches and a piece of brass.
jeeper46
Well-known member
One of the few things I still use from my days as a Diemaker are all the various brass rods I accumulated back then. All sorts of diameters and lengths, like the photo above. I use them all the time on my various old cars and bikes.
Maybe I'm missing something, but roll pins with brass makes me think they will get messed up. Aren't the pins spring steel? I would think it might risk chewing up the punch a bit. But you probaly have more specific knowledge of what you need to do. Would be curious to hear how it works out tho.
matt_i
Well-known member
Here is my fave for roll pins. Mayhew (steel) punches with a small hemisphere on the end to center the punch.
https://www.amazon.com/dp/B004FCO5EG/?tag=atomicindus08-20
As far as making general purpose bronze punches, I would go with SAE 660/ CDA 932 "cast bronze" and avoid the SAE 841 (forgot the CDA number) sintered bronze "oilite" as its porous and brittle and will fracture. The SAE 660 is malleable and will not fracture without bending or mushrooming first.
https://www.amazon.com/dp/B004FCO5EG/?tag=atomicindus08-20
As far as making general purpose bronze punches, I would go with SAE 660/ CDA 932 "cast bronze" and avoid the SAE 841 (forgot the CDA number) sintered bronze "oilite" as its porous and brittle and will fracture. The SAE 660 is malleable and will not fracture without bending or mushrooming first.
Bagherra
Well-known member
I made a couple on a lathe when I was in Iraq...
Got bored and one of the machinists let me make a couple. Pretty simple and straightforward...I
I'll post pix when I get home!
Got bored and one of the machinists let me make a couple. Pretty simple and straightforward...I
I'll post pix when I get home!
Dave455
Well-known member
I've made up all manner of punches over the years, generally in bronze or brass if I need something that won't leave marks!
To be honest, if you're working with roll pins (well, what I'd call a roll pin, which is technically a 'Spring torsion pin') you don't want a soft punch, you want the hardest you can get! This is because where the ends of the pin are beveled , you basically are pushing against a hardened knife edge. Priory, in the U.K. offer specific punches for these pins, which also have a small lug to centre the punch properly.
If you want a 'non marking' punch you are generally better off with brass rather than bronze.
Only in extreme circumstances, where you need a relatively large amount of force but still don't want to use a steel punch, would I use bronze. In these cases I use 'phosphor bronze' as it comes from a local engineering supplier. Superb stuff, lovely to work, takes an awesome finish, but expensive!
Consider also, taking a set of regular steel punches, then bevelling the edges slightly, and polishing the tips! This reduces marks if you have to use the steel punch!
To be honest, if you're working with roll pins (well, what I'd call a roll pin, which is technically a 'Spring torsion pin') you don't want a soft punch, you want the hardest you can get! This is because where the ends of the pin are beveled , you basically are pushing against a hardened knife edge. Priory, in the U.K. offer specific punches for these pins, which also have a small lug to centre the punch properly.
If you want a 'non marking' punch you are generally better off with brass rather than bronze.
Only in extreme circumstances, where you need a relatively large amount of force but still don't want to use a steel punch, would I use bronze. In these cases I use 'phosphor bronze' as it comes from a local engineering supplier. Superb stuff, lovely to work, takes an awesome finish, but expensive!
Consider also, taking a set of regular steel punches, then bevelling the edges slightly, and polishing the tips! This reduces marks if you have to use the steel punch!
ilovevocs
Well-known member
I like to use o1 drill rod and heat treat the end with torch and small can of oil; then temper with torch.
While your at it make some nice center punches too.
While your at it make some nice center punches too.
Mecha
Well-known member
I would echo and agree exactly with what was said here. Used to use bronze and brass tools in a non-sparking factory environment, and (this isn't much help) would suggest using the hardest brass available for tooling longevity. You sort of know it isn't going to hold up to excessive abuse anyhow but that is the point that the brass takes the absorption and deformation while the steel takes the force. If you absolutely want non-marring I'd go bronze as well.
Dave455
Well-known member
I used to do a lot of assembly work and often ended up making a few tools for each job. The first picture shows a steel punch, a brass punch and some custom screwdrivers - stored in a block of wood - one block per job!
The second picture shows some small brass punches and some brass hammers, all 'home brew'!
The second picture shows some small brass punches and some brass hammers, all 'home brew'!
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I'm not talking about brass punches, I need bronze, brass is not suitable for these type of roll pins and neither is Steel, We currently use snap-on bronze punches, but they don't offer all the sizes I would like to have, so I was simply looking for a bronze grade suitable for punches. I really am not well versed in bronze and the different types, but these roll pins require a lot of force to remove, and using steel, even a roll pin punch, will make things go south quick.
Tom
Most of the time the Mayhew roll pin punches are the most suitable, but in any case, you are looking for an aluminum bronze alloy if you want something really tough. Investigate the different grades of Ampco bronze to get an idea. Ampco 18 is somewhat available, but Ampco 21 is even tougher.
You will want to get pricing for them.
Even these however will not hold up like a steel punch.
Most of the time the Mayhew roll pin punches are the most suitable, but in any case, you are looking for an aluminum bronze alloy if you want something really tough. Investigate the different grades of Ampco bronze to get an idea. Ampco 18 is somewhat available, but Ampco 21 is even tougher.
You will want to get pricing for them.
Even these however will not hold up like a steel punch.
pugglewuggle
Well-known member
Hi Tom, I know this is old, but can you tell me why you would want a bronze punch over brass, or brass over bronze? Thank you!
He may not frequent this forum any more. Someone else may know the answer.
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Last Activity: 01-27-2018 08:32 PM
Hey, yeah sorry I haven’t been around in a while but basically the reason I need this type of punch is because we have to knock out roll pins that are very large and probably much different then a roll pin you may imagine, it’s essentially a sheet of spring steel that is rolled up into a round pin, they are extremely tight in the bore and have no spring tension like a normal roll pin would, they work off of an interface fit. So using bronze is essential due to brass being to soft for the force involved in hitting them out and steel mushrooming and further tightening the pin in the hole.
I should note this pin isn’t “hollow” like a normal roll pin, the sheet is rolled tightly and almost resembles a solid pin.
I still love using bronze for many applications tho as it can allow you to strike thing you normally wouldn’t, with tools you normally couldn’t.
I should note this pin isn’t “hollow” like a normal roll pin, the sheet is rolled tightly and almost resembles a solid pin.
I still love using bronze for many applications tho as it can allow you to strike thing you normally wouldn’t, with tools you normally couldn’t.
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OccupantRJ
Well-known member
Look at 642 silicon aluminum bronze.
matt_i
Well-known member
I would describe this as a coiled pin.
I would use 1018 or W1 drill rod, in the annealed state, face on the lathe. Will be considerably softer than the spring temper 1095 (or whatever) they are using for the coiled pin. Short pin to keep it from buckling and a heavier hammer to let the mass move something.