Tapping threads

[Alpha Crow]

Have to tap out a SV650 oil drain plug. 12mm going to a 14mm.

Never tapped anything before, though I build furniture and do lots of small repairs to mechanical things. Looks like it doesn't have a lower oil pan, it's just part of the freaking crank case.

My plan is to put it on it's side (onto plenty of padding plus it has frame sliders) and use a 90 degree braced electric drill.

Now how does this usually work? Does the bit grab the metal and pull itself through or do I need to push hard?

Thanks for advice. Hate to ask such nummy questions, but I already messed up the freaking 12mm threads, can't screw up this time.

[sykotek-xx]

You do not put a tap in a drill.

You do not put a tap in a drill.

You do not put a tap in a drill.

You need to drill out the hole with the appropriate size bit for the tap, then the tap is run thru by hand with a handle.

I was also about to tell you to make sure you drain the oil if you are going to lay the bike down..... :icon_duh:

[Alpha Crow]

Sorry, I'm an idiot and didn't write that out right (just got off 24 hour shift)

Meant, to drill it out to proper size (as specified by tap package), using 90 degree braced drill with the bit it states necessary to tap.

For the hand tap, does it grab on it's own or do I have to push hard? Do you advance it slowly and inspect the threads on the way or is it better to crank down on it and go and it will self guide?

I know it's a dumb question, details on a easy seeming process, but I'm worried something will go wrong. I already stripped the damn threads as it is

Cutting fluid? (reading other websites)

Needed or no? Doesn't state anything, just use some light oil or something specific?

[Involute]

Starting the Tap is the most critical part of the job. DO IT SLOWLY! Do everything within your power to keep the Tap perpendicular to the hole. You will need to apply a fair amount of pressure while keeping it square in order to start the thread properly. If it wiggles a little at first don't panic. Just keep trying to keep it in line. I would get it started and threaded up to about 1/2 turn and then back it out and clean the Tap. Once you are sure you have it started correctly and it's square to the hole you can destress a little. The hard part is over. Until you get about 3 full threads you'll need to be careful to keep it square. After that it will start to follow the hole on it's own and pull itself in.

You want to make sure you get as many chips out with the Tap as you can so you can coat the Tap with a thick grease before making any cuts, including the first one. Thread it in until you start to cut again. Turn and cut about 1/8 turn and back it all the way out. Clean it, re-coat it and repeat until you get the hole fully threaded. You should be in no hurry. Take numerous "Baby Cuts" rather than a few big cuts.

The Grease on the Tap will help keep the chips on the Tap when you pull it out. Take your time. You get one shot at this unless you want to go to the next size thread.

If I forgot anything others will fill in the blanks.

Good luck with it. It's not tough to do if you take your time and use common sense.

[lois]

Starting the Tap is the most critical part of the job. DO IT SLOWLY! Do everything within your power to keep the Tap perpendicular to the hole. You will need to apply a fair amount of pressure while keeping it square in order to start the thread properly. If it wiggles a little at first don't panic. Just keep trying to keep it in line. I would get it started and threaded up to about 1/2 turn and then back it out and clean the Tap. Once you are sure you have it started correctly and it's square to the hole you can destress a little. The hard part is over. Until you get about 3 full threads you'll need to be careful to keep it square. After that it will start to follow the hole on it's own and pull itself in.

You want to make sure you get as many chips out with the Tap as you can so you can coat the Tap with a thick grease before making any cuts, including the first one. Thread it in until you start to cut again. Turn and cut about 1/8 turn and back it all the way out. Clean it, re-coat it and repeat until you get the hole fully threaded. You should be in no hurry. Take numerous "Baby Cuts" rather than a few big cuts.

The Grease on the Tap will help keep the chips on the Tap when you pull it out. Take your time. You get one shot at this unless you want to go to the next size thread.

If I forgot anything others will fill in the blanks.

Good luck with it. It's not tough to do if you take your time and use common sense.

When I to do jobs like this, I use a shop vac to pick up the cuttings. After you get the tap "started" put the nozzle of the shop vac right up to the tap as your going in. Rule of thumb is 2 turns in with tap, then one turn out to clear the tap of cuttings that may bind against the tap and screw up threads. I use this method when tapping into oil pans , transmision cases, what ever, to keep cuttings from getting into the oilcase etc.

If you don't have a shop vac, then +1 on the heavy grease as stated above.

[shovelstrokeed]

A couple of rules and a tip or two.

First off, don't forget to pack the flutes of the drill bit with grease as well as those of the tap. You don't want chips in the crank case.

You will be tapping aluminum, go to a good hardware store or get on the internet and order a tapping fluid specifically designed for that job. I like Tap Free but there are other products. Aluminum tends to gall and tear rather than cut at even the very low speeds of hand tapping. The lubricant makes all the difference, in particular on the first couple of threads.

With a multi-flute tap, you should "break chip", back out the tap about 90 degrees for every 90 degrees that you cut. Getting in a hurry here can ruin both the job and your day.

Finally, should have been first but I just now thought of it, beware the drill bit grabbing and twisting your stuff up just as you break through the bottom of the hole. Really ease up on the pressure as you approach the end of the cut. You probably don't have much in the way of wall thickness to work with here so that grab can come quicker than you'd expect.

[lois]

A couple of rules and a tip or two.

First off, don't forget to pack the flutes of the drill bit with grease as well as those of the tap. You don't want chips in the crank case.

You will be tapping aluminum, go to a good hardware store or get on the internet and order a tapping fluid specifically designed for that job. I like Tap Free but there are other products. Aluminum tends to gall and tear rather than cut at even the very low speeds of hand tapping. The lubricant makes all the difference, in particular on the first couple of threads.

With a multi-flute tap, you should "break chip", back out the tap about 90 degrees for every 90 degrees that you cut. Getting in a hurry here can ruin both the job and your day.

Finally, should have been first but I just now thought of it, beware the drill bit grabbing and twisting your stuff up just as you break through the bottom of the hole. Really ease up on the pressure as you approach the end of the cut. You probably don't have much in the way of wall thickness to work with here so that grab can come quicker than you'd expect.

+1 on post

Speaking of tapping aluminum, many years ago an old machinest told me something crazy. He said the exact same thing about aluminum galling and tearing if you just used grease or oil. He said (get this) use whole milk as lube when tapping aluminum and it will tap clean.

Forgot all about this for many years, but, tried it when I hit a snag drilling out an aluminum head....worked like a charm....believe it or not.

Don't know why it works, maybe something to do with the fat in the whole milk.

[blackhawkxx]

You do not put a tap in a drill.

You do not put a tap in a drill.

You do not put a tap in a drill.

Hey, I saw them do it on American Choppers.

[airborneXX]

You do not put a tap in a drill.

You do not put a tap in a drill.

You do not put a tap in a drill.

Hey, I saw them do it on American Choppers.

They also assemble bikes with large hammers and adjustable wrenches :icon_nono:

If I forgot anything others will fill in the blanks.

Yes fucko you did forget something...

BEEEEER

[2equis]

First off, don't forget to pack the flutes of the drill bit with grease as well as those of the tap. You don't want chips in the crank case

Great tip!!

[HERBXX]

I dont think you will have to drill out much , the stripped hole should be pretty close to the right size. When i went from a 12 to a 14 on my nighthawk i didn't drill the hole out first. Just make sure you get a good quality tap that matches the pitch of the oil plug. It would be best if both the new and old plug had the same pitch.

[Involute]

If I forgot anything others will fill in the blanks.

Yes fucko you did forget something...

BEEEEER

Sorry.

MAKE SURE IT'S GOOD BEER!

[redxxrdr]

+1 on using grease on the tap. If you must drill, use every size smaller bit, increasing size until you get to the size recommended for the tap.

A additional thought, since you will have the crankcase drained, you could use a vaccuum cleaner on Blow forcing air into the oil filler. Just make sure there is no dirt in the hose. This would allow you to just use cutting oil on the tap, and should force all the chips out past the flutes. As has been said, tap in small steps. 10-20 degrees then reverse. I often dip my tap in a cleaner ( gasoline, seafoam, light oil) to remove the chips. Add more cutting oil and start again.