What Do I Do?

[wm460]

What Do I Do?

I am making this bracket for my lathe, I need to tap a 4mm hole. the long tap is a starter tap from a 40 pce set, the short tap is the plug tap from a 3 pce set.

How can I thread it deeper with out buying a long tap for this one of job?

 

[fortress]

I'm not very mechanically minded Mark, is there any way you could cut that thread longer?

 

[Dalboy]

i think you will need to go and buy a new tap Mark

 

[Woody]

Would a long thin socket do the job to extend the tap

 

[Penpal]

Use drill attachment as Woody suggests should work. Go to the engineering place they should have one to help you out. take out the cross bar in the tap holder and insert it one half at a time.

Peter.

 

[sfurini]

I'm assuming that only one half needs the thread - can't you cut the corner off the opposite side and thread it from the bottom as it were - the tap looks plenty long enough to do that? If you're worried about the thread going into the other half, just drill that a fraction bigger than the tap??

 

[wm460]

The shaft of the tap is larger than the thread cutting area.

Go to the engineering place they should have one to help you out. take out the cross bar in the tap holder and insert it one half at a time.

Peter.

500 km down the road.

 

[sfurini]

That's why I'm suggesting you tap from the back of the hole as the thread only needs to be in one side? a bit like this sketch....the tap section looks long enough on the photo

 

[Penpal]

If space or grip is a problem I have taken off the cross bar on the tap holder and machined it down. IMHO the solution Stewart has given solves the problem. There is nothing to stop you Mark from drilling straight through and simply bolting the unit holding the nut from the other end with a spring washer and or double nut it. This vworks for me.

Peter.

 

[wm460]

Thanks Stewart makes sense now, will have a look tomorrow arvo.

A clearer pic.