Trevvy 2nd July 2014, 09:34 AM Hi guys, new to this site, have spent all last night browsing to see what's up, must say, very impressed.
Ok, here's my question.
I,m cutting three 1 meter long by 1"1/4 6TP Acme external threads and making three nuts to suit.
The boring bar I,m using is 1/2" round, a little to flexable, so have decided to make a new unit from 1" bar stock.
All other boring bars I,ve seen have had the tool steel tip brazed onto the bar.
What bronze do I use.I have some hard bronze and normal multi purse bronze
Ueee 2nd July 2014, 10:28 AM Hi Trevvy and welcome,
I have only ever used standard manganese or silicon bronze rods for brazing, not that i have done many tool bits but it works well. You can also weld your HSS bit to the bar, you don't need to worry about getting it too hot just don't quench it.
Either that or broach a square hole in your bar and add a locking screw in the end and you can use it with other tool bits.
Cheers,
Ew
PDW 2nd July 2014, 12:07 PM Hi Trevvy and welcome,
I have only ever used standard manganese or silicon bronze rods for brazing, not that i have done many tool bits but it works well. You can also weld your HSS bit to the bar, you don't need to worry about getting it too hot just don't quench it.
Sure, provided you don't mind stress cracking in the HAZ.
I've done this using a lot of preheat (dull red) and slow cooling, got away with it, don't recommend it. If you are going to weld HSS to other steels, use E309 rods or similar - you want the ductility.
Personally if I had brazing gear on hand, I'd braze it. Whatever hard brazing rods you use will be plenty strong enough.
PDW
snapatap 2nd July 2014, 01:55 PM At work we stick weld hss to mild steel bars with stainless rods. Never had an issue. Most of the time it's for cutting acme or square threads. Try to make your bar as big as possible, some times we mill the bar back a bit for clearance .
welder 2nd July 2014, 05:39 PM +1 on the stick welding of hss we also do it at work with stainless rods and haven't had an issue.
Vernonv 3rd July 2014, 08:24 AM I haven't brazed any HSS tips to boring bars, but for carbide tips I just use ordinary 15% silver solder with a little brazing flux (both available from plumbing and hardware stores).
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