2mm square push broach?

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Hauk

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Hi,
I need to clean up some square holes in rather small brass castings.

The holes are 2mm X 2mm and about 4mm deep. They go all the way through the casting, so clearing out chips is not an issue.

I have found several 2mm X 2mm rotating square broaches, but this concept is a bit too advanced for my use.

What I am looking for is a simple push-type broach. Tolerances are not too tight.

Is something like this available commercially? Or do I have to grind my own? If I need to grind my own I would love to see a drawing with the correct angles/rakes.

Best regards,
Haavard H.
 
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BaronJ

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Hi Hauk,

Have a look at this thread, post 92.

http://www.homemodelenginemachinist.com/showthread.php?t=22047&page=10

It describes my hand slotting tool. I needed to put a 4 mm slot into a bronze bush. So I purchased a piece of 4 mm square tool steel. To do what you want I would buy a piece of 2 mm square, or even better if it didn't interfere with anything, a 2 x 4 mm section and then I would have both 2 and 4 mm broaches.

As far as sharpening is concerned I just treated it as I would a lathe tool bit.

HTH.
 

Hauk

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Hi Hauk,

Have a look at this thread, post 92.

http://www.homemodelenginemachinist.com/showthread.php?t=22047&page=10

It describes my hand slotting tool. I needed to put a 4 mm slot into a bronze bush. So I purchased a piece of 4 mm square tool steel. To do what you want I would buy a piece of 2 mm square, or even better if it didn't interfere with anything, a 2 x 4 mm section and then I would have both 2 and 4 mm broaches.

As far as sharpening is concerned I just treated it as I would a lathe tool bit.

HTH.
Anyone know of a source for 2mm square tool steel? I could also use som 1,5X1,5mm tool steel.

Maybe watchmakers use such tiny tools?

Best regards,
Haavard H
 

BaronJ

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Depending upon the tool suppliers around you 2 mm square is a common size, often used for small lathe boring bar bits. I have some 5/64" square that I use in one of mine.
 

Theclockworks

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Depending upon the tool suppliers around you 2 mm square is a common size, often used for small lathe boring bar bits. I have some 5/64" square that I use in one of mine.
Could you not use silver steel
 

Hauk

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I could possible use silver steel, but I still need a source for it!

The tool suppliers in my area stock very little of stuff like this, so I am entirely dependent on finding what I need online.
 

Wizard69

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You could try these guys to see if they would do custom grinds: http://www.arwarnerco.com

You could also try MSCDirect, Travers and other online sellers. MSC does have 1.5mm bits listed.

Spend some time on the net. Google is your friend.
 

Hauk

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You could try these guys to see if they would do custom grinds: http://www.arwarnerco.com

You could also try MSCDirect, Travers and other online sellers. MSC does have 1.5mm bits listed.

Spend some time on the net. Google is your friend.
Belive me, I do spend some time on the net searching for all kinds of stuff. But I have failed to find tool blanks or silver steel in the required dimensins (1,5X1,5mm or 2X2mm)

MSCDirect has a lot of interesting stuff, but as far as I could see, no tool blanks in the above sizes.
 

BaronJ

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Unless you have some means for machining to size and hardening it, silver steel / drill rod is no use to you. There are a number of suppliers, "Michel Fox, Cromwells, Buck & Hickman etc that stock "Dormer, Presto, etc" HSS tool bits in both metric and imperial sizes from 1mm round and square forms upwards. Some have carbide tool bits as well.
 

Wizard69

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Belive me, I do spend some time on the net searching for all kinds of stuff. But I have failed to find tool blanks or silver steel in the required dimensins (1,5X1,5mm or 2X2mm)

MSCDirect has a lot of interesting stuff, but as far as I could see, no tool blanks in the above sizes.

Well I'm pretty sure it was MSCDirect that I was looking at. They had 1.5 & 3 mm square listed. It would be a total pain in the but to do free hand but you could always grind 3 mm down. It would be easy with a tool grinder but most of us don't have one!

I would be the first to suggest that MSC's online catalogs suck.
 

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