# Question about Tapping Brass



## bearswood (Jan 2, 2008)

After tapping a #2-56 hole into a piece of brass, the screw does not want to seat. It goes farther in with a flat head but not as far with a hex head. Do not want to add lubricate because it is in the frame. The frame is for the DIY Mason Bogie in the MLC. I making it out of brass do not like the way it tracks in styrene. I hope this is in the right topic.


George from northern Indiana


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## John J (Dec 29, 2007)

Can you get us some pictures?

Could it be that it is bottoming out in the hole?

Could there be metal shavings from the tapping in the hole? 

The bolt shaft threads may be a little rough at the top near the head.

Do you have Die of the same threads you ccould run over the bolt to clean them up? 

JJ


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## xo18thfa (Jan 2, 2008)

Are you using brass plate for the hobby shop? If so, that brass is a different alloy then round, rectangle or hex bar stock. Sheet is usually alloy #260. It is hard to tap. It's miserable to cut and drill too. Try lubricating it, I know you don't want to, but will clean up. Maybe try a new, sharper tap.

A better brass to use is alloy #360. McMaster-Carr, Online Metals, Metals Express, Speedy Metals Online have it.


Other options maybe to avoid tapping it altogether and use a nut/bolt. Or use coll rolled sheet steel. CRS taps fine and is not that hard to work with.


Sheet brass is a tough one.


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## armorsmith (Jun 1, 2008)

George, 

Keep in mind that there are two things affecting your dilemma (if I understand the question correctly). First, almost all fasteners are manufactured today using a rolled thread method, which will NOT give complete threads up to the head - hence there will always be a short lead in. Second, your tap in the brass bar/plate will be a sharp cornered hole. It is difficult at best to try to fit a sharp corner into a rounded corner. My best suggestion is to put a small chamfer on the top of the tapped hole, this will help by allowing the lead in thread a little depth to set into. Also, if you do the chamfer before you tap the hole, it will make starting the tap much easier. 

Bob C.


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## Don Howard (Jan 2, 2008)

I have linked to a picture of the head of a 2-56 Hex Head Machine Screw from Microfasteners.

http://picasaweb.google.com/lh/phot...directlink
or









From:


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## armorsmith (Jun 1, 2008)

Don, 

Your photograph demonstrates exactly what I was talking about. Something I thought about after posting last time, you may be able to run a 2-56 die up the bolt backwards and possibly get a little more threading closer to the head of the bolt, but be careful no to break the bolt. 

Good luck. 

Bob C.


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## Bruce Chandler (Jan 2, 2008)

Can you just make the hole a bit wider at the top? Big enough to accommodate that part with no thread? It looks like it would not need to be more than 1/32" deep.

Be very careful with those brass screws - they're not real strong.


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## bearswood (Jan 2, 2008)

As you can see the screws touch the outside with enlarged hole but the hex heads do not. The top of the screw does not come into play. I hope the picture comes through.


George from northern Indiana


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## Greg Elmassian (Jan 3, 2008)

I'm confused... the picture is not in enough detail to really see anything. 

I'm not clear on "touch the outside with enlarged hole but the hex heads do not". 

Are both pieces tapped, or just the "second piece" the bolt goes into? 

I would think this would be simple, the first piece has a "clearance hole", the bolt slides through it, no engagement of threads. 
The second piece only needs a tapped hole deep enough. 

Regards, Greg


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## bearswood (Jan 2, 2008)

I am sorry I know the picture stinks but could not get any closer. The outside piece is redrilled larger after I drilled the inside and tapped it but the hex head does not want to seat even though the depth is past the length of the bolt. I might just order from Microfastners and chuck the stuff that is tagged Walther's that I bought at my LHS. It is getting frustrating dealing with styrene now brass is being a pain in the neck. Maybe I just carve the whole bloody engine out of basswood, instead. Maybe I should copy Warther's engines he did in ebony and ivory plus other woods. If you get to Dover, Ohio or nearby you have to see the musuem. http://www.warthers.com/carving.htm

George from northern Indiana


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## bearswood (Jan 2, 2008)

Okay, now I am really confused. They went in with no problem. I want to thank everyone for their advice but it seems that I am becoming one of my Jr. High students stuck in my own ozone. Maybe I thought I was from downunder and was following the flow of toilet. Now I am more confused and befuddled than before. Thanks again for all the help and advice. You would think I would know better. I think I am going to put the train down and go carve something or build a Welsh chair. No, I think I will go finish the radiant floor heating system that will make my wife happy and the dogs.

George from northern Indiana


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## Greg Elmassian (Jan 3, 2008)

possibly the "clearance" holes were large enough by themselves, but a slight misalignment made it so certain bolts were not perfectly centered in the "clearance holes" and made it so they did not want to seat fully. 

In any case, seems that all is well now. 

Don't give up now since you conquered the mystery! 

Regards, Greg


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