All I have to do is drill and tap them, and on Lukestuff he said use 13/32 drill and all I can find is 11/32 and 3/8. So I got the 3/8 because its closer to it in size. Will the 12mmx1.75mm tap work ok still?

 

You should be fine. Be sure that the drill and tap are sharp (as in new if possible) and use a quality cutting fluid.

 

Craftman pro new in pack. Can I use wd40 or pb blast. I wanted just need a tap but all I see is kits for 100 bucks, and I won't be taping nothing soon or ever lol

 

WD40 I wouldn't recommend nor PB blaster. I believe any hardware store will sell a cutting oil in small volumes.
Having said that, will the small amount of tapping that needs to be done, I can imagine that just about any motor oil would work as a substitute. Just don't quote me on it. I'd hate to be responsible for you blowing out the threads and ruining a modified spindle.

 

Find the correct size drill bit. It may work with the smaller on, but you run the risk of breaking the tap.

 

This is no place to cut corners, you can look up a drill and tap chart online to make sure you're using the correct drill size for your tap. If you use to small of a drill, you risk breaking your tap. If it's too big, you will lose thread engagement and therefore lose strength in your thread. if you cant find the right size bit in a local store, you can order one from mcmaster.com or elsewhere.

 

For the sake of 1/32" I would think that the risk of breaking the tap is minimal. Of course this is dependent on the operators level of skill.
I agree on the oversize bit. It's important that the thread height is correct so as to provide the greatest contact possible.
Having said that, the proper size drill bit wouldn't hurt.

 

IMO easiest is to drill a 10mm hole and tap for M12. 12 needs a 10.2 or thereabouts hole, a 10mm bit will always give a slightly larger hole. Quality machine drill and presto done. I have done quite a few sets this way. use 12.9 Allen heads and done.

 

You need to get the correct size. As pointed out the correct size for 75% threads is 10.2mm. I like to drill then ream to size but I understand most people won't do that. I would buy a 10.2mm bit from McMaster Carr, $8 and done. Do it right, or take it to a machine shop.

You also need to make sure the holes are drilled parallel to to the spindle snout. Are you using a drill press and ensuring the spindle is parallel with the bit?

Finally, the spindles are cast iron. You do not need lube when drilling and tapping cast iron. Cuts like butter.

John

 

The casting is butter soft to tap. I had a 10.2mm bit but I figured I'd test a high quality 10mm drill bit and guess what, without issue I can tap the proper M12 threads. I do use high dollar machine bits, not some cheap chinese tap set. The 10.2mm bit will not make a 10.2mm hole... guaranteed!

 

Yup, easiest material I have ever had to tap. Easier than even plastic.

The phenomenon you mention is why I ream all tapped holes. No oversized holes, and very round. I am not at all surprised you were able to tap it with a 10mm hole. Here is the states you will not find even a 10mm drill bit in stores. So its special order either way.

John

 

Use a machine tap/spiral flute, you will thank yourself for doing so.



Can't get a 10mm drill bit? WOW!

 

I use spiral POINT tap myself. They have been a huge help on tapping tough stainless. Never used the spiral FLUTE ones after hearing some horror stories from people breaking them in stainless. But as we have both pointed out, any tap will cut our spindles with no issue.

Yes, you will not find 10mm or any metric drill bit in normal hardware stores in the US. But I don't buy any machine tools from hardware stores any more. So for me it doesn't really matter.

You can buy metric taps locally and use the nearest 1/64" drill bit. That is what most people do.

 

I can buy metric bits locally, but I agree, they are not usually a off the shelf part here in the USA. Taps and bolts and the like sure, but just not bits. However a good hardware store will have all the fractional, numerical and letter size drill bits, so it easy enough to find something withing a hair of perfect.

 

www.mcmaster.com/#

Buy ANY size you want

 

So, after all this, is it safe to say that our original poster could use his slightly undersized drill bit and motor oil to successfully drill and tap his spindles?

 

3/8" is more than a little undersized. It is almost 0.030" smaller. He can try it, if he can even start it straight with the hole that much undersized. A countersink would help, but that is another thing to buy. I still say buy the correct bit.

Lube does not help in cast iron and I would never recommend making a mess if its not going to help.

Just my opinion. But I will say I have never regretted spending the extra time and money to do something right.

 

Agreed.

 

I will just take them to a shop I was trying to do the swap for under 50 bucks, well I have to get the adapter brackets. Because I don't wanna buy anything online and the ripping and running looking for 1 would just be gas.

 

Wouldnt hurt to get a decent drill index for the future

For limited jobs harbor freight is excellent
Drill index 1/16 to 1/2 by 64ths $30
Metric tap/die set $15

Would I use them in a shop? No
Are they good for small jobs like spindle mods where each tool may see 4-6 holes in its lifetime? Absolutely

 

www.mcmaster.com/#

That's where you need to go.

Period.

Why?

McMaster-Carr has been around for DECADES; since LONG BEFORE Algore invented the Interwebz. Very large distributor of industrial products.

IMO should be near the top of every car enthusiast's Favorites list.

 

McMaster is awesome, I used to order a bunch of stuff there but when they stopped shipping intl. I haven't bought much from them. Too bad ... they have quality hardware.

 

dont skimp out on stuff. nothing wrong with purchasing online just make sure its credible. the aim of most people here its to do it right the first time and not make these cars any more of hack jobs than most of their owners have. buy the correct stuff. 50 bucks wont cut it so save up if you need to.

 

I understand they got hit with some ITAR fines so they stopped international shipping. Sounds like a story to me but who knows.

I place 1-3 orders a week from them. Great folks.

 

Do this!!! You can thank us later.

 

Isn't it simpler just to walk into your local industrial supplier and buy it off the shelf?
This stuff isn't exactly difficult to get. At least here it isn't. Just ask any millwright were they shop.
(No disrespect intended).

 

For me McMaster is cheaper and sells better quality stuff than my local Grainger. Almost everything sold by McMaster is made in USA.

Surely in a pinch, the local place will do. I'm sure it all depends how good your local supplier is.