Thread: Welding HSS

Hi all,
I need to make a tool for shaving out a gear keyway on the lathe.
The keyway is 5mm in an 18mm bore.
My plan is to stick weld a piece of HSS into the end of a round steel bar but I'm a little worried about affecting the HSS hardness.
What should I do after welding it ?

Could you braze or silver solder it instead? Neither of those will change the temper. I have never seen hss weeded successfully.

Originally Posted by caskwarrior

Could you braze or silver solder it instead? Neither of those will change the temper. I have never seen hss weeded successfully.

I guess I could try silver solder, if my torch will get it hot enough. I've only got LPG.
But then I'd have to get the HSS red hot for silver solder, wouldn't that change the temper ?

The temp of the HSS won't be affected by welding - that is if you can weld it but like CW says I have not seen it welded, brazed certainly.
HSS has to be held at red heat for a long time to substantially affect the hardness and even then it only changes by a few points on the hardness scale.
Annealing requires hours of heat.

Originally Posted by phaser

I guess I could try silver solder, if my torch will get it hot enough. I've only got LPG.

I regularly use a primus lpg torch to silver solder carbide but I have to use the high silver content and fire bricks. How big is the cross section?

Hi Guys,

I agree with Ralph, I've never seen it welded either ! Usually it is silver soldered or brazed with sifbronze.

As far as cutting a keyway is concerned just use a grub screw to secure the HSS. Its a lot easier.

Originally Posted by BaronJ

Hi Guys,

I agree with Ralph, I've never seen it welded either ! Usually it is silver soldered or brazed with sifbronze.

As far as cutting a keyway is concerned just use a grub screw to secure the HSS. Its a lot easier.

A grub screw was the original idea but how do you make a 5mm square hole through a 14mm round bar and on an angle ?
I could drill it but it's a hell of a lot of filing to make it square.

316L stainless rods are good for welding hss to steel.

Sometimes I also use them for welding cast iron, steel to cast iron, cast steel.

cheers, shed

https://www.boc.com.au/shop/en/au/bo...rodes#product1

It doesn't nessecarily need to be a square hole, as long as the grub screw is square to the face, that should be enough to hold it in position.
Kryn

Hi Phaser,

A grub screw was the original idea but how do you make a 5mm square hole through a 14mm round bar and on an angle ?

You don't !

Just drill a hole in the end of a suitable piece of bar, fit your HSS bit into the hole and secure with a grub screw.

Put the gear in the lathe chuck and the cutter in the tool post, use the lathe saddle to move the tool in and out to cut the keyway. You will need to grind the cutting face correctly and you will only take off a few thou per cut.

26062014-08.jpg
Here is one I did earlier.
26062014-01.jpg
I found that cutting more than one key slot very tiring, so I made a tool to help.

19062014-04.jpg 19062014-02.jpg
This is the tool. There is just a grub screw to secure a length of suitable tool steel. In your case for a 5 mm wide key, use a 5 mm wide piece of tool steel.

Originally Posted by phaser

Hi all,
I need to make a tool for shaving out a gear keyway on the lathe.
The keyway is 5mm in an 18mm bore.
My plan is to stick weld a piece of HSS into the end of a round steel bar but I'm a little worried about affecting the HSS hardness.
What should I do after welding it ?

Use it.

Originally Posted by caskwarrior

Could you braze or silver solder it instead? Neither of those will change the temper. I have never seen hss weeded successfully.

Me too, I can't seem to find HSS weeds, but I have welded it and used it after welding with Mig and stick.

Originally Posted by BaronJ

Hi Phaser,



You don't !

Just drill a hole in the end of a suitable piece of bar, fit your HSS bit into the hole and secure with a grub screw.

Put the gear in the lathe chuck and the cutter in the tool post, use the lathe saddle to move the tool in and out to cut the keyway. You will need to grind the cutting face correctly and you will only take off a few thou per cut.

26062014-08.jpg
Here is one I did earlier.
26062014-01.jpg
I found that cutting more than one key slot very tiring, so I made a tool to help.

19062014-04.jpg 19062014-02.jpg
This is the tool. There is just a grub screw to secure a length of suitable tool steel. In your case for a 5 mm wide key, use a 5 mm wide piece of tool steel.

I have made several internal keyways using this same technique. I concur that it is a laborious task if you have to make several but as a one-off it still works very well. I really need to make one of those lever setups.

Simon

Originally Posted by caskwarrior

I regularly use a primus lpg torch to silver solder carbide but I have to use the high silver content and fire bricks. How big is the cross section?

My idea was to weld or solder it in like this.
A round bar about 12mm slotted with a hacksaw and files to take the 5mm HSS bit.

keyway cutter.jpg

A stronger way is to mill an angled slot in the holder lengthwise and put the HSS in there and grind to suit. I will get a photo of one I prepared earlier.