15mm and 7/16" diameter HSS tool steel bar

Yes well thanks for the advice and I agree the route of 15mm HSS bar seems way too expensive and I will make a mild steel bar to take small HSS inserts. For the 7/16" I like the idea of soldering (ordinary electric solder?) on old carbide tips but you must have a very large soldering iron or do you heat it up with a gas torch beforehand?

How about one of these, loctite a sleeve on for the 15mm, turn it down a tad for the 7/16

**LINK**

Normally brazed or sliver soldered.

Andrew

Duncan £100 is well outside my target!

Andrew I think the MIG welder will come out from the bottom shelf for this then

Brazing and silver soldering would be difficult with a MIG welder. You only need a gas torch to silver solder.

Paul

Adam, Mild steel is not a particularly good material to make your boring bars from, better to choose something tougher say EN8, EN19 or EN24T. Silver steel is OK but not great either IMO, personally I use EN24T and it works well.

John

Not bad Duncan. Thanks

Andrew/Paul, when talking Silver Soldering do you mean the cheap Aluminium Alloy rods used with a gas canister blow torch? Or are you talking about Silver-Flo and if so which one?

I use this set of indexable holders made for boring heads 90% of the time.

Some Banggood can be questionable but most of our suppliers have something between the two extreams that Duncan has shown.

Adam,

No not aluminium, silver solder. I have various grades kicking around the shed, a fair bit of the old easy flo No2 which apparently you are not supposed to use these days because of the Cadmium content. Also have some Cup alloys 434 and Johnson Mathey silver flo. Any of them will do pretty well. Use a high temp flux like Tenacity No 5 or I would think Cup HT5. For small jobs you can get away with the hand held DIY self contained torch with integral cylinder if you can arrange some fire bricks to concentrate / conserve the heat.

Paul.

Apart from wearing away the grinding stone...

Adam - I have sent you a PM

John