Taps&Dies

[GeorgiePorgie]

Dunno why but I always have a problem when I want to cut a thread on a rod or tap a hole.

I have this 13mm/1/2" tube that I need to put a thread on,what size should the die be?

1/2"?

 

[nickk]

if it is exactly 1/2" then u need 1/2" unf/unc[or bsw]/bsf.If its 13mm you'l have to turn it down to 1/2" as there's no m13 thread as far as i know.

 

[brightspark]

Dunno why but I always have a problem when I want to cut a thread on a rod or tap a hole.

I have this 13mm/1/2" tube that I need to put a thread on,what size should the die be?

1/2"?

yep 1/2 inch providing thats the tube o d

 

[ouchmyfinger]

Dunno why but I always have a problem when I want to cut a thread on a rod or tap a hole.

I have this 13mm/1/2" tube that I need to put a thread on,what size should the die be?

1/2"?

Thats your prob, 13 mm is not 1/2" , whatever size your going to to cut, look up correct bore or diameter for the imperial or metric size.

 

[brightspark]

Thats your prob, 13 mm is not 1/2" , whatever size your going to to cut, look up correct bore or diameter for the imperial or metric size.

half inch is 12.70mm

 

[mike 109444]

Asuming you are trying to put a thread on the outside of a 1/2 tube (and not tap inside) You will need to check that the wall thickness is enough. If it's thin wall then you may cut through or collaps the tube with UNC or BSW and would need to go for UNF. If you have a zues book it should give the depth of a thread pitch and times by 2 to give the depth that the dies (or screw cuting) will go to.

 

[ouchmyfinger]

half inch is 12.70mm

Correct, so tap and die size will not be the same for both.

 

[hotrodder]

Pretty much all been said while i was typing but FWIW...

What you need is a Zeus book which contains thread data and tapping drill sizes for all the usual suspects. Cheap as chips and a play with google will get a free/scanned copy if that's too expensive

When cutting threads into/onto tube don't forget that thread pitch makes a difference for example male 1/2" UNF has a core dia of 0.4387" while 1/2" UNC = 0.4056"... nearly 1mm smaller due to the coarser thread which could be enough to 'make or break' things.

A decent lead in (taper) will make life easier when cutting male threads (1st cut tap is tapered for the same reasons)

ETA thread data here too... http://www.britishfasteners.com/threads/unc.html but a zeus is more pocket shaped than a computer and laminated so it doesn't mind oily fingers

 

[GeorgiePorgie]

Ok here's what it measures on a digi caliper.

13.04mm or 0.513"

Wall thickness is 2.5mm

Ta,men.

 

[ouchmyfinger]

Asuming you are trying to put a thread on the outside of a 1/2 tube (and not tap inside) You will need to check that the wall thickness is enough. If it's thin wall then you may cut through or collaps the tube with UNC or BSW and would need to go for UNF. If you have a zues book it should give the depth of a thread pitch and times by 2 to give the depth that the dies (or screw cuting) will go to.

Mike, it does,nt matter what thread you are cutting, 1/2 unc, 1/2" unf, 1/2 " whit, they are all 1/2" The point being , check with your zeus book as regarding your drill size, because they will differ per different thread.

 

[ouchmyfinger]

Pretty much all been said while i was typing but FWIW...

What you need is a Zeus book which contains thread data and tapping drill sizes for all the usual suspects. Cheap as chips and a play with google will get a free/scanned copy if that's too expensive

When cutting threads into/onto tube don't forget that thread pitch makes a difference for example male 1/2" UNF has a core dia of 0.4387" while 1/2" UNC = 0.4056"... nearly 1mm smaller due to the coarser thread which could be enough to 'make or break' things.

A decent lead in (taper) will make life easier when cutting male threads (1st cut tap is tapered for the same reasons)

ETA thread data here too... http://www.britishfasteners.com/threads/unc.html but a zeus is more pocket shaped than a computer and laminated so it doesn't mind oily fingers

Hotrodder, beg to differ , thread pitch is the distance between the crowns of two apex,s your talking about thread depth and your right in tube it makes a difference

 

[hotrodder]

Thread depth (along with several other things) can be and is expressed as a function of pitch, the link i posted has a drawing showing that. Here's one for metric... http://mdmetric.com/tech/M-thead%20600.htm

 

[ouchmyfinger]

Thread depth (along with several other things) can be and is expressed as a function of pitch, the link i posted has a drawing showing that. Here's one for metric... http://mdmetric.com/tech/M-thead%20600.htm

The pictch of a thread is the distance measured parallel to its axis..
any pitch in inches or mm is 1 divided by number of threads per inch , any other p you ars looking at "hot" is not the thread pitch.

 

[Pete.]

Mike, it does,nt matter what thread you are cutting, 1/2 unc, 1/2" unf, 1/2 " whit, they are all 1/2" The point being , check with your zeus book as regarding your drill size, because they will differ per different thread.

That's for internal threads - Mike was referring to cutting external threads. What Hotrodder said was bang on too - the pitch makes a difference because greater pitch = greater thread depth.

You should read what people have said instead of automatically contradicting what they haven't.

 

[Jester]

1/4" BSP thread has an outside diameter of 13.157mm - close enough

 

[GeorgiePorgie]

I'll try again.

Anyone know what die I should use for the bar size in #9

Thanks.

 

[wyn]

What are you going to connect it to?

Are you going to tap the thread in whatever it connects to?

As others have said, there are quite a few different threads you could put on it.

 

[Jester]

I'll try again.

Anyone know what die I should use for the bar size in #9

Thanks.

As I said - 1/4" BSP is close enough -
Outer dia 13.157mm
Inner dia 11.445mm
Tpi 19
Tapping drill 11.6mm

Plenty of pipe fittings available to suit too

 

[hotrodder]

Cheers Pete. One more link on the subject, note that 0.54127p is mentioned in both the links i posted The first hit (bolt science) is a good resource for threaded fasteners

George, if you want more than the options you've been given you need to tell us more.

13.04mm OD, 2.5mm wall so ID is 13.04 - (2 x 2.5) = 8.04mm or 0.32" Several different threads could be cut on that but we don't know...

1. what it's for i.e. whether there'll be enough wall thickness left for strength/stiffness or whether it matters if it's a bit (to very) rough/mickey mouse or even what selection of taps and dies you have
2. if you have access to a lathe to size the OD properly
3. if that matters (see point 1)

1/4" bsp won't require machining the OD first and will leave plenty of meat but you're gonna have a sloppy thread fit as the tube is undersize. The other options are to machine the OD, pay someone to do it if you can't machine the OD or buy some different stock

 

[GeorgiePorgie]

http://www.wickes.co.uk/sand-blasting-kit-3m/invt/186908/

I bought this SB pressurewasher attachment,I knew it would not fit a Karcher PW but the price was too good to miss as the same attachment on ebay and the net is somerwhere in the region of £25 the cheapest.

So I have cut off the brass gun attachment and used my mini lathe to turn an attachment to suit the Karcher gun,pretty easy really.

I now need to put a thread on the wickes SB attachment tube end and tap a thread on the gun attachment I turned on the lathe.

the gun attachment I turned on the lathe is made from Aluminium bar.