'what oil'
Seriously.....cutting oil as recommended for use when cutting the thread to insert the helicoil insert into......special stuff? Any old lubricant? any good substitute suggestions?
Rocol RTD or Rocol Cleancut
'what oil'
Seriously.....cutting oil as recommended for use when cutting the thread to insert the helicoil insert into......special stuff? Any old lubricant? any good substitute suggestions?
Fairy nuff
I have to wait until the parcel from Motorworks arrives anyway, as the two ring gaskets and the bigger oval gasket have got to be replaced at the same time.
The 'fitting one handed' aspect doesn't come into play in this case...the stud on the other side is still there and still tight and in good condition (I did order two studs though just in case)
I like understanding things though, so it was worth asking
EDIT.......while I have some proper minds focussed on this.......I'm going top break the cardinal rule and ask 'what oil'
Seriously.....cutting oil as recommended for use when cutting the thread to insert the helicoil insert into......special stuff? Any old lubricant? any good substitute suggestions?
Sorry![]()
Rocol RTD or Rocol Cleancut
For a one off a drop or two of EP80/90 will help. The alloy is far softer than the stud so it will be enough rather than buying a tin of cutting compound. Years ago they used tallow, foul smelling stuff.
again 
Not being funny but do you know how to properly use a tap?

Rotate the tap in a tub of LM grease. This will lubricate and also pick up all the bits of swarf.
Not being funny but do you know how to properly use a tap?
Shhhh, Bill could start a whole new 'thread'![]()






I'm looking forward to the bit when the tap bottoms out so you give it some more and the tap snaps![]()


Whatever you do to get the swarf out and even when drilling - please make sure you wear eye protectionI don't have an airline, so I was intending to stick a drinking straw into the freshly tapped hole to blow out any swarf.....
Advance a bit, reverse a bit to let swarf come out, go back in, rinse and repeat
I'm going to poke a widget into the hole that the stud came out of to establish the depth, and will wrap a bit of insulting tape around the tap to show the limit I want to go to.
I don't have an airline, so I was intending to stick a drinking straw into the freshly tapped hole to blow out any swarf.....all hi-tech stuff here
Then, using the insert tool, I'll screw in the insert, again, marking the depth off......If it needs two inserts, I'll knock the locating tab off with the tool and remove it (straw again, IDK, but I'll make sure I get it out) then if it needs a second insert, I'll screw that in and remove the tab again.

Whatever you do to get the swarf out and even when drilling - please make sure you wear eye protection![]()
ps It's always interesting to read posts like this - even if much of the info is already known![]()

Get a spiral fluted helicoil tap and you won't be needing either an airline or a straw!
Get the correct size insert and you won't need to bodge two inserts in one hole!
I'm operating on a miniscule budget, so I'll have to do with what I have.
The kit i got today is this from Neilsen.
I have no idea if that's a 'spiral fluted helicoil tap' or not, but it's what I have
Looking at the inserts, I'm going to need two of them.....I'll just have to be careful when inserting the second one so it doesn't start compressing the first out of the thread.
It's all good fun![]()
As you say , it's all good fun! Looking at the inserts, I'm going to need two of them.....I'll just have to be careful when inserting the second one so it doesn't start compressing the first out of the thread*.

So you've bought the kit before knowing how to do the jobAs you say , it's all good fun!
Ps: No they're not spiral fluted.
You've just reminded me , I need to buy a lump hammer - I have a clutch to adjust...

Bollocks.....
Use only one helicoil. If you damage the inner one, you will not get it out again when a second insert is against it.
One helicoil insert is ample fixing for a standard M8 engineering stud to screw into it in your casting.
I told you earlier, the M8 inserted hole has higher strength than a basic M8 hole into alloy, so the extra thread you are trying to gain by fitting two inserts is overkill, and risky to achieve.
Once you have your new studs there, screw an insert on to the shorter of the two threaded ends and you'll see what I mean, the inserts are longer when fitted, and your kit describes the M8 insert as M8x1.25x8mm, which should be ample for this application.....

Best get someone who knows what they're doing to successfully complete the task in hand
Much less grief, I expect![]()


.....it certainly makes sense that the insert will form to the new thread and expand/uncoil along its channel![]()