Broken tap in engine mount

[Sean Bowf]

I will be happy to EDM the tap out if you send it to me.
Mike Stutzman

I have no idea what an EDM is...but sent it out to the other Mike today to see what he can do for me. If that doesnt work, I will shoot you a PM.

Thanks everyone for your inputs and offers to help. I figured I would just get ideas on how to get it out here...but I got a lot more than that. IW is a great place to be.

Thanks again,

Sean

 

[DJT]

To get it out without damage use the EDM as mentioned above, I saw this work, relatively quick and no damage. Any alkali or acid will eat the aluminum first!! If the mount rails dont cost that much I would buy a new set as the labor, shipping etc will cost more than a new set of rails.I havent broken many taps in Aluminum, but 304 stainless I have broken many!!

good luck,

mike sr

I work in a machine shop and we don't let a 4 dollar tap ruin a 400 dollar part, we use acid to remove broken taps from aluminum.

 

[Sean Bowf]

Well...just got done tapping the other side...worked like a gem with the additional knowledge you guys gave me... Chamfered, Cobalt tap oil, and I did not cut till I felt as much tension as I did earlier...piece of cake. Wish I knew yesterday, what I know today...

Sean

 

[Mike Hughes]

If you ain't learning some thing new every day of your life, it is time to hang it up. Still learning myself and getting better all the while.

Mike

 

[glenng]

I will be happy to EDM the tap out if you send it to me.
Mike Stutzman

I have no idea what an EDM is...but sent it out to the other Mike today to see what he can do for me. If that doesnt work, I will shoot you a PM.

Thanks everyone for your inputs and offers to help. I figured I would just get ideas on how to get it out here...but I got a lot more than that. IW is a great place to be.

Thanks again,

Sean

Sean, EDM means Electrial discharge machining. The broken screw is burned out, and a tap is run through to clean out any remnaints of the broken bolt. Results=perfect thread without oversizing hole

 

[Ron Saxvik]

I have found that ProLong SPL100 Super Penetrating Lubricant Spray to be

best out there for any cutting operations on aluminum. This is not listed

in their information sheets as being one of it's uses but have been using it

for drilling, tapping, and any other cutting operations on aluminum. Just

make sure that you clean your tools after using as it has something in it that

will discolor and cause rust on steel.

http://www.prolong.com/master.aspx?http://...ng.com/faq.aspx

 

[HendricX]

As I'm not a native English speaker , wondering what is meant by 2 or 3 FLUTE taps.

In Europe you have tapping-sets ... 3 taps .. each cutting more(deeper) thread. (mostly used on thicker material)

And there is a Hand/Machine tap .. only one tap (0,75"), gradualy cutting deeper by each 0,25". (mostly used on thinner material)

 

[Sean Bowf]

As I'm not a native English speaker , wondering what is meant by 2 or 3 FLUTE taps.In Europe you have tapping-sets ... 3 taps .. each cutting more(deeper) thread. (mostly used on thicker material)

And there is a Hand/Machine tap .. only one tap (0,75"), gradualy cutting deeper by each 0,25". (mostly used on thinner material)

Hendrick, it is talking about the number or cutting columns. My 4-40 tap only has two cutting columns with a gap between them, while my 6-32 tap has three cutting columns with a gap between them.

I didnt really think about it, but I guess different metals are best tapped with different number of flutes. Attached is an end pic of my 6-32 tap.

Sean

PS, your english is fine...

 

[HendricX]

Onboard translation :lol: ... but not al 'technical-terms'.

I expected it would be something like that , but was not sure.

I checked my (Metrical) taps ... from M1,5 to M5 they have 3 flutes&gaps from M6 to M14 having 4 flutes&gaps.

The Imperial-taps 1/4"x28 & 1/4"x32 are also having 4 flutes&gaps.

For normal measurements a made a Imperial/Metric chart , is there something similar for boltsizes ?

Because I haven't the faintest idea what 6-32 is :huh:

BTW

The EDM ........... found it earlier as the answer here ..... with Google

 

[Tom Foley]

Order a copy of the Machinists Handbook from MSC , it will be a lifetime guideline for any metal related operation !

 

[HendricX]

Tom ... please explain MSC (I'm one .. but that does not help) :lol: ... weblink would be nice.

 

[Mike Byer]

Tom ... please explain MSC (I'm one .. but that does not help) :lol: ... weblink would be nice.

try this http://www1.mscdirect.com/cgi/nnsrhm

 

[Mark Bullard]

I have tap a lot of holes over the years. Repairing threads and making new ones. The best taps that I use are "Spiral Point Taps" and "Spiral Flute Taps". The taps that you buy at Lowes, Home Depot, Sears and others are just standard taps. The standard taps are harder to tap with and are easier to break than the spiral taps. The reason is you can not get rid of the chips and this is what jams the tap. I do a lot of tapping in my mill using the spiral taps. What make them work is the Spiral Point pushes the chips out the bottom of the hole and the Spiral Flute remove the chips from the hole. Now the Spiral Flute is a easier tap to break because the way it is made and the only holes I use them on is blind holes. Now the number of flutes is not a problem with these taps. But if your hand tapping the tap will start straighter with more flutes but is not required. Also most of the smaller taps are only 2 flute. You can find these taps very easy at www.mcmaster.com. And if you ever see me at a race ask me and I may have a set of the common sizes in Spiral Point.

 

[HendricX]

For normal measurements a made a Imperial/Metric chart , is there something similar for boltsizes ?Because I haven't the faintest idea what 6-32 is :huh:

Found one

http://www.precisionscrewandbolt.com/metric

 

[glenng]

As I'm not a native English speaker , wondering what is meant by 2 or 3 FLUTE taps.In Europe you have tapping-sets ... 3 taps .. each cutting more(deeper) thread. (mostly used on thicker material)

And there is a Hand/Machine tap .. only one tap (0,75"), gradualy cutting deeper by each 0,25". (mostly used on thinner material)

Hendrick, it is talking about the number or cutting columns. My 4-40 tap only has two cutting columns with a gap between them, while my 6-32 tap has three cutting columns with a gap between them.

I didnt really think about it, but I guess different metals are best tapped with different number of flutes. Attached is an end pic of my 6-32 tap.

Sean

PS, your english is fine...

Sean, It's not really about the number of flutes for different materials. Smaller taps break easier than larger ones. a 3/8-16 tap in a 4 flute design is fine. For anything smaller than 10-32 I prefer 2 flute design as they do not break as easily-as they have a heftier cross section-less material ground away. Remember you only need 70% of full thread depth to get a strong thread-don't drill your pilot holes too small. Glenn

 

[Sean Bowf]

Sean, It's not really about the number of flutes for different materials. Smaller taps break easier than larger ones. a 3/8-16 tap in a 4 flute design is fine. For anything smaller than 10-32 I prefer 2 flute design as they do not break as easily-as they have a heftier cross section-less material ground away. Remember you only need 70% of full thread depth to get a strong thread-don't drill your pilot holes too small. Glenn

Budget boater here Glenn...I buy my taps from lowes. They come with the drill bit. No idea what size it is or anything when I used it. Come as a pair for about $4.50. Just put a caliper on it...it is .105 inch diameter on the shank.

Sean

 

[Mark Leyde]

[budget boater here Glenn...I buy my taps from lowes. They come with the drill bit. No idea what size it is or anything when I used it. Come as a pair for about $4.50. Just put a caliper on it...it is .105 inch diameter on the shank.
Sean

Sean, We all like to keep the buget down on are builds. But it's not cheap if you would have needed to buy a new mount. You can get by with cheap hand tools like pliers and wrenches. But one MUST buy very good tools when it comes to things like taps and drills.

I am a toolmaker. I build plastic injection molds. I have been in the trade since 1988. I can EDM or holepop that tap out and you will not even know that there was ever a broken tap in it. Also here is a GREAT peice of advise for everyone here. DO NOT EVER EVER EVER USE THEM CHEAP @SS TAPS from the home improvment store or the local hardware store. Them cheap taps always cut oversize or break. Save your self the trouble and buy a tap from one of the machine shop supply houses like J&L Industrial supply or MSC.

If anyone needs a tap removed drop me a PM.

Mark

 

[Mike Byer]

Rest easy all, the operation was a success and the rail is on the way home. A valuable lesson learned, and some good information shared, can't wait to do it again.

mb

 

[Sean Bowf]

Thanks Mike, was afraid I boogered it up too much with my attempts.

Look forward to seeing how it, and the tap, looks.

All in all...I learned a lot with this...which is what it is all about.

Sean

 

[HendricX]

Yupzzzzzzzzz

That's what boards / forums are good for.

Do stupid things so the experts can show-off and brag.