[Red89]

When tapping a thread is it necessary to use some form of lube ? I have been using a dry lube stick, what sort is recommended ? I am needing to do a heap of M6 threads, but after drilling a 5mm hole I seem to be chewing out the thread on the tap and it certainly doesnt want to start easily. It does eventually bite and cuts fine once it gets going but it seems to take forever to get started

[Gwagensteve]

What are you tapping in to? I use cutting lube and often tap with a cordless drill at that size.

Correct drill size is 4.8mm, are you using a taper or inter tap, or a bottoming tap? Bottoming taps can be very hard to start.

Steve.

[mrw82]

you can get taps in 3 types, taper, intermediate and bottoming. a taper tap is needed to cut a new thread, intermediate is good for cleaning our a previously cut thread, and a plug tap is used for tapping into a blind hole (after starting the thread with a taper tap)
Get some rocol rtd or trefolex, they are proper cutting compounds and will make a massive difference to the ease of tapping and life of the tap.

Steve the correct drill size for a 6mm tap with 1.0mm pitch is 5mm. Where do you get 4.8 from?

[zooky08]

i use trefolex alot, make sure you get the right one, there high speed trefolex and cutting compound trefolex.

[abclarke]

zooky08 wrote:

i use trefolex alot, make sure you get the right one, there high speed trefolexmand cutting compound trefolex.

x2. Only stuff we ever use at work.

[Gwagensteve]

mrw82 wrote:

you can get taps in 3 types, taper, intermediate and bottoming. a taper tap is needed to cut a new thread, intermediate is good for cleaning our a previously cut thread, and a plug tap is used for tapping into a blind hole (after starting the thread with a taper tap)
Get some rocol rtd or trefolex, they are proper cutting compounds and will make a massive difference to the ease of tapping and life of the tap.

Steve the correct drill size for a 6mm tap with 1.0mm pitch is 5mm. Where do you get 4.8 from?

Oops- pwned- I was thinking 8mm with a 1.25 thread - 6.8mm

Steve

[Red89]

The cheapo tap set Ive got only has intermediate and bottoming taps, I have been tapping into 2.5mm pipe and flat bar. Looks like I'm off to the toolshop, cheers guys.

[BlueSuzy]

Yep cheapo taps are exactly that.

Get sutton or similar from a proper toolshop

[Fatzook]

BlueSuzy wrote:

Yep cheapo taps are exactly that.

Get sutton or similar from a proper toolshop

X2. And if you are tapping by hand, drive the tap in one full turn, then back half a turn. This will clear the swarf from the tap and help prevent the new thread from being burred.

[Red89]

Life is sooo much easier when you have the right tools Bought a taper tap and some Rocol ( they had run out of Trefolex ) the other day and ran off 12 threads this arvo in the same time it would have taken me to do 2 before, cheers all

BlueSuzy wrote:

Yep cheapo taps are exactly that.

Get sutton or similar from a proper toolshop

Yer it appears most are simply thread repair kits not tap and die sets.

Fatzook wrote:

And if you are tapping by hand, drive the tap in one full turn, then back half a turn. This will clear the swarf from the tap and help prevent the new thread from being burred.

I do remember that much from highschool metal work

[Bugsta]

I once had to tap a new thread into an old holden diff housing. I could not get a good start because I was working on my back, and just could not keep it straight and keep the pressure on it whilst turning the handle. My solution was to put the tap into small battery drill where I could concentrate on keeping it straight and enough pressure. Drove it slowly. Worked a charm.

[BlueSuzy]

I dislike tapping with a drill, because if you smash the tap, it can be hard to remove in the job. Of course with a battery drill you can use the torque control, but can still be risky

I'd rather it by feel. Even if it is alot of holes

[Teracis]

BlueSuzy wrote:

I dislike tapping with a drill, because if you smash the tap, it can be hard to remove in the job. Of course with a battery drill you can use the torque control, but can still be risky

I'd rather it by feel. Even if it is alot of holes

I've tapped thousands of holes with a battery drill, we were doing 5mm tapped holes into C channel up the side of conveyors, we made it fun by having races with each other, I definitely wasn't going to be doing those by hand...

Also, if you manage to smash the tap in the hole, if there's enough sticking out you can usually grab on with the battery drill or pliers and wind it back out!

[BlueSuzy]

Of course a conveyor is a different story.

Used to do massive rivets in a train conveyor, Weren't doing them by hand 10rivets in a line, 100mm apart, The next line was maybe 200mm away, at least 22M long belt, Including drilling..What fun..