carbide tipped boring bars

I bought a set of 3/4 shank carbide inserted boring bars. I have two of them with broken tips due various mistakes I made. I was wondering if it is possible to get new carbide inserts and braze them in. I hate to buy a new set as these are short shank boring bars and are very handy in some tool setups.

Reply to
desperado
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Reply to
Richard J Kinch

Sure! Also, concider HSS chunks for special uses.

Reply to
Tom Gardner

This is great to know!

But >

Reply to
Proctologically Violated©®

Yup, I do it all the time for special function bits. Considering the cost of some of the bits on the market it is hardly worthwhile for standard bits. Bugs

Reply to
Bugs

It could be brass /bronze which could contribute to the breakage. It could be silver braze alloy corroded with age.

Sweat the old one out with a torch. Try not to burn the braze alloy.

The only problem may be with the new insert. Not all carbide wets well. Put a good amount of flux on the new insert with a cut bit of wire and heat it. If it flows out well then it is good.

tom

Reply to
president

I don't know that the color appearance is much help identifying an alloy. The pricey 45 percent silver stuff still has a gold or brass color.

I forget where I researched this, but the cadmium and high silver alloy is said to be critical to getting a shock-resistant braze on carbide. The more common HVAC rods I presume would be more prone to snap off.

I have used the silver/cadmium rods, with the Allstate S-200 flux, on a number of hand and power tools, and it has always wetted easily, filled and filleted nicely, and held up superbly, with nothing more than Turbotorch propane/air flame.

Reply to
Richard J Kinch

Probably on our web site. (We have a new version of our book Building Superior Brazed Tools.) Our specialization is in high end applications such as very narrow saw tips in mills, oil well heads, satellites, etc. You are correct that the choice of alloy can make a huge difference.

However less expensive alloys can also work very well as the need for bond strength and impact resistance drops. Arguably you need greater strengths for a saw tip than for a braze joint in an air conditioning system. Depending on the braze area (the bigger the better) and the amount and direction of the force applied a much less expensive alloy can be suitable.

Tom

Reply to
president

Yes, that's it:

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Reply to
Richard J Kinch

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