Spares for Qualters & Smith power hacksaw

If there's enough metal, bore it out and Loctite in a threaded bush. Cost is time and a bit of scrap.

If not, invest in some Helicoils or a clone kit.. Might cost you £55 inc VAT and delivery for a 1/2" BSW kit from J&L

Mark Rand RTFM

I thought about this. Not sure if Loctite alone would be strong enough as it carries a heavy load. There's just about enough metal, but I don't have a mill with which to bore the hole. Just a bench drill, which is too small. Instead I wondered about making a new male-threaded component with a longer thread, to engage with the remaining female thread at the bottom of the hole (I suspect the reason for the failure is that the male-threaded component is unoriginal and too short). So that's a possibility, but I don't have the necessary die and stock, and it's some way from being a good solution.

The size required is 5/8" BSF. The only kit I could find was an Armstrong Armacoil kit at more than twice the price you quote. Cheekily, it doesn't even include the drill. But it wouldn't fit in my bench drill's 1/2" chuck anyway.

Best wishes,

Chris

I think you might be surprised how strong a well-executed loctite joint can be, especially at this kind of diameter.

Cheap enough - though cutting a 5/8" BSW by hand with a die is no joke. Do you have a screwcutting lathe? If not, do you have a friend who has?

You can easily get a blacksmith's drill (anything up to 1", with a 1/2" shank). Whether your drill has the grunt to drive it is another question.

David

Sorry for the late response.

Maybe. But I'm reluctant. I want to be certain it'll be strong enough and won't degrade in the future.

I think I've found someone with the part I need, so hopefully I won't need to modify the clamping block. But it looks like the pivot posts are unoriginal. It's possible the thread failed because the male thread is shorter than intended, so I may still be making the pivot posts.

I can imagine that cutting a 5/8" thread with a die is hard work. I can't think what I'd grip 5/8" round stock in to stop it rotating. And then there's getting the die started square. I often use the drill press (unpowered) for this with smaller dies, but it won't work with 5/8". What's the best way of doing it?

My father has a Myford Super 7, which I think could be used for screw cutting. But I don't think he's ever used it for this purpose, so there probably isn't a 55 degree thread cutting tool with it. And the previous owner modified the wiring so that both "Forward" and "Reverse" on the control lever do the same thing.

I looked into this. Considerably more expensive than buying an ordinary twist drill of that size, and I'm doubtful that my drill press could drive it in cast iron. It copes with a 16 mm blacksmith's drill in aluminium, just about, but cast iron would probably be pushing my luck.

Thanks for the thoughts.

Best wishes,

Chris