Metric threaded rod - pitches

[snowyskiesau]

For a table saw fence project I'm embarking on, I need a 2 metre length of 16 - 20mm threaded rod.
No problems in getting this but at that size, the pitch that most all seems to be metric coarse i.e. 2.0 or 2.5

Is threaded rod of that diameter made in a metric fine pitch? A 1mm pitch would be ideal butt 2mm would be OK.

[Machtool]

It has to be one continuous 2 metre lenght? That will cut down your options. Not sure you will find it longer than 1 metre.

All fasteners in Tullamarine list an M20 x 1.5, but 1 metre long only.

http://www.allfasteners.com.au/threaded-rod-metric-fine-thread-mild-steel-plain-unplated-black

Regards Phil.

[KBs PensNmore]

Hi, in 16 mm you have a choice of 1.5 or 2 mm pitch and 20 mm has 1.5 and 2.5 mm pitch, according to my little black book.

Fasteners Australia have it in a 3 metre length price M 16 $35.88 and M 20 $57.75 Zinc Finished

Kryn

[snowyskiesau]

For the application, it needs to be either 1mm or 2mm pitch, not 1/2mm.
According to one table I found, 18mm and 20mm metric fine comes in 1mm and 2mm pitches.

For accuracy, it really needs to be a continuous length.

[Stustoys]

For accuracy, it really needs to be a continuous length.
Joining it to any sensible level of accuracy shouldn't to to much of a problem.

Though a 2m length sure would be easier

Stuart

[electrosteam]

T.E.A Transmissions in Queensland have threaded rod and nuts designed for accurate linear positioning.
Their stock 16 and 20 mm sizes are 4 mm pitch with a 0.1 mm per 300 mm accumulating error in lengths to 2 m.
Other sizes available by request.

https://www.tea.net.au/Portals/0/uploads/PAGE%2034.pdf

John.

[snowyskiesau]

T.E.A Transmissions in Queensland have threaded rod and nuts designed for accurate linear positioning.



Thanks for the link but this would be way too expensive for what's required.

[KBs PensNmore]

Anyone out there got a 2.4 m BC lathe, and can cut a 1mm pitch thread in 20mm bar, to help this poor man out of his misery :D
Kryn

[Ueee]

Bolt do M16x2 in 3m lengths. Not exactly what you want though. https://www.bolt.com.au/mild-steel-rod-metric-plain-c-1010_1817_1818_1819.html

[snowyskiesau]

2mm would be OK.On the table saw fence, this would allow a minimum increment of 2mm which is probably enough. The original design allows for 1/16"
https://www.youtube.com/channel/UC0T7tvy44mlQCjaTtparOZw/videos

[KBs PensNmore]

You could mount an electric motor on the end of the shaft, hook it up to a computer and have a CNC fence guide:D Or put a handle on the end and have infinite adjustment for the fence. Just a couple of different thoughts.

[Michael G]

As an alternative, how about using a solid rod (clamp the fence to the rod) and on the end have a threaded section 200mm long say that can provide the fine adjustment. Even with a 2mm pitch, adjusting your fence from say 1m to 1.5m is going to get awfully old awfully quick. (BTDT)

Michael

[PDW]

As an alternative, how about using a solid rod (clamp the fence to the rod) and on the end have a threaded section 200mm long say that can provide the fine adjustment. Even with a 2mm pitch, adjusting your fence from say 1m to 1.5m is going to get awfully old awfully quick. (BTDT)

Michael

That's exactly how the fence on my old Woodfast table saw works.

Except the idiots used a right hand thread so I always turn it the wrong way!!!

PDW

[snowyskiesau]

As an alternative, how about using a solid rod (clamp the fence to the rod) and on the end have a threaded section 200mm long say that can provide the fine adjustment. Even with a 2mm pitch, adjusting your fence from say 1m to 1.5m is going to get awfully old awfully quick. (BTDT)

Michael

The threaded rod isn't turned to locate the fence, it's fixed in position and is used to lock the fence to within 1/16" of where you want it (imperial measurement used in the linked design)
Actually the rod can be turned half a rotation if you need 1/32" accuracy. This is why a 2mm pitch is OK as half a turn adjustment gives you a 1mm accuracy.

If I use a thread pitch of 1.5 (or 2.5) then I'm (theoretically) within 1.5mm or 2.5mm whereas I'd prefer this to be a whole number. Hope this makes sense to anyone who hasn't viewed the video.

[Steamwhisperer]

I just watched the video and was wondering if you need the whole length threaded or just the area where the third nuts (half nuts) clamp.
It would be easier to screwcut a shorter section in the middle or wherever out of solid bar than purchase that length of running thread.
Probably cheaper as well. I know I can screwcut at least 700mm comfortably out of any size bar or pipe.

Phil

[snowyskiesau]

Ideally, you need to be able to position the fence anywhere along its 2 metre length and lock it down which means it all has to be threaded.

Just had the thought that if I went with a 1.5mm pitch and changed the detent knob to have three positions then I could still get 1mm spacing. Not as straight forward but not too much extra work.

As Ueee has pointed out, 16mm is readily available in 2mm pitch and for the application, that diameter would probably be enough.

It's a shame we went metric as 3/4" 16TPI is readily and cheaply available :)