Tap and die sizes

[beefsheeparable]

So I’ve got an 18mm hole and a 19mm rod, struggling to work out if I’d be able to thread them together? And what size tap and dies I’d need if so?
cheers!

 

[Tomr10]

What size thread you after 18 mm?

 

[beefsheeparable]

I think so, would I need 18mm bar to cut 18mm thread though?

 

[spark plug]

With those size materials the thread size that would fit would be M19x1, which is rather odd ball. If you could go up to a 20mm rod with the 18mm hole that would be more standards at M20x2.

 

[beefsheeparable]

Ahhh ok, thanks for clearing that up! No can do with the rod size, was thinking tapping it would be a more refined solution rather than just getting the welder out but that’s looking what I might do now!

 

[spark plug]

Another option would be for a 3/4” UNF thread, your rod would be ok but you would need a 17.5mm hole.

 

[beefsheeparable]

Afraid I’m stuck with an 18mm hole and 19mm rod, https://www.ebay.co.uk/itm/1pc-M19-...767059?hash=item441406d093:g:DZEAAOSw3KFWgLdX, do the job?

 

[beefsheeparable]

Wrong size and silly long delivery, welder it is!

 

[tinman]

you could put a helicoil into the hole to make up for the difference, M18x2.5 needs a 18.5 hole, then turn down the bar end and thread it to M18x2.5 and screw it in.

 

[Tomr10]

That's a fair size though what's it for

 

[tinman]

Afraid I’m stuck with an 18mm hole and 19mm rod, https://www.ebay.co.uk/itm/1pc-M19-...767059?hash=item441406d093:g:DZEAAOSw3KFWgLdX, do the job?

no, because that stuff is only rubbish, you'd break one or the other before you got the threads made.

 

[beefsheeparable]

Having a bash at making an electric fence winder, and rather than buy the freewheel bosses off Rappa for 25 a pop I’m having a go at making them from £6 bike freewheels off eBay... I’ve got a piece of steel to make a boss to weld the freewheel to just thought threading it would be a bit more refined

12-18T Single Speed Bicycle Steel Freewheel Cog Sprocket Bike Tools Spare Parts | eBay

Bike Bicycle Single Speed Steel Freewheel Cog 12-18T Spinning Flywheel. 1 Freewheel. The smaller the number of teeth, the faster the speed. If the rear flywheel is 16-tooth and you use the 12-tooth rear flywheel, then its speed can be increased by 30%.

www.ebay.co.uk

 

[Tomr10]

Having a bash at making an electric fence winder, and rather than buy the freewheel bosses off Rappa for 25 a pop I’m having a go at making them from £6 bike freewheels off eBay... I’ve got a piece of steel to make a boss to weld the freewheel to just thought threading it would be a bit more refined

12-18T Single Speed Bicycle Steel Freewheel Cog Sprocket Bike Tools Spare Parts | eBay

Bike Bicycle Single Speed Steel Freewheel Cog 12-18T Spinning Flywheel. 1 Freewheel. The smaller the number of teeth, the faster the speed. If the rear flywheel is 16-tooth and you use the 12-tooth rear flywheel, then its speed can be increased by 30%.

www.ebay.co.uk

Could you not thread shaft and put a nut either side

 

[Tomr10]

Or make an interference fit

 

[beefsheeparable]

I’ll have a look, worth a try, was thinking a bolt either side might interfere with it spinning freely

 

[Tomr10]

I’ll have a look, worth a try, was thinking a bolt either side might interfere with it spinning freely

If it did could slacken it off. One thing that might work slight taper on the shaft problem is enough fit without interfering with movement like you sayb