[pittbull7934]

One another thread, somone told me to use a thread chaser instead of a tap to clean the portion of the block where the head bolts go into. I went to sears and they had no such thing and could not find it in their computer.

Where can I get one? Is it that important I use one as opposed to a tap?

[dgcantrellsr]

To my limited knowledge a thread chaser is used on bolts, gotta use taps on threads in blocks and such.

Originally Posted by pittbull7934

One another thread, somone told me to use a thread chaser instead of a tap to clean the portion of the block where the head bolts go into. I went to sears and they had no such thing and could not find it in their computer.

Where can I get one? Is it that important I use one as opposed to a tap?

[scrimshaw]

Originally Posted by pittbull7934

One another thread, somone told me to use a thread chaser instead of a tap to clean the portion of the block where the head bolts go into. I went to sears and they had no such thing and could not find it in their computer.

Where can I get one? Is it that important I use one as opposed to a tap?

That is correct, a thread chaser simply cleans/tidies a thread up and is typically used on older bolt holes where the bolt won't go in properly. You can use a tap for this but you have to be very carefull not to cut your original threads up. I have also been met with blank stares when I tried to buy one to chase some spark plug threads on an aluminum head, the local auto places are not the best places to get them. They are available online. I was able to borrow one at a local machine shop.

[scrimshaw]

It's possible to make your own thread chaser by taking a bolt with the correct thread and cutting 3 or 4 vertical slots equidistant from each other on the length of the bolt threads. The depth of the cut should be down to just beyond the minor diameter of the thread.

[cucumber1949]

My understanding is that a thread chaser will clean up the threads without cutting the material while a tap will remove material.

[oldred]

Originally Posted by scrimshaw

It's possible to make your own thread chaser by taking a bolt with the correct thread and cutting 3 or 4 vertical slots equidistant from each other on the length of the bolt threads. The depth of the cut should be down to just beyond the minor diameter of the thread.

Just to add a to this, make sure to use a grade 8 or better bolt! Also make sure the slots are evenly spaced and the threads are thoroughly de-burred after the slots are cut, use a soft bolt, poorly cut slots or fail to de-burr and it is very easy to get a home made thread chaser cross threaded in the hole. It is a good idea with these home made chasers to run a proper sized nut onto the modified bolt several times using anti-seize before attempting to repair any damaged threads with it. Some people may scoff at doing this but I have done it many times and have had really good success with it, the trick is to be careful with the slots and to use a hard bolt and anti-seize.



To repair spark plug threads just go to almost any auto parts and buy a spark plug chaser, it will be double ended with both common thread sizes. This thing is probably no harder than a grade 8 bolt and will not cut threads but with a little anti-seize applied will easily repair most Aluminum head spark plug threads as well as most cast iron heads.

[oldred]

Originally Posted by cucumber1949

My understanding is that a thread chaser will clean up the threads without cutting the material while a tap will remove material.

That is the way they work and a thread chaser is much better at repairing damaged threads than a tap or die. With a chaser you will simply be moving metal around and straightening the threads while a thread cutting tap or die will usually do just that-cut the threads-and if you are not very careful with them you can easily remove threads instead of straightening them!

[scrimshaw]

Originally Posted by oldred

Just to add a to this, make sure to use a grade 8 or better bolt! Also make sure the slots are evenly spaced and the threads are thoroughly de-burred after the slots are cut, use a soft bolt, poorly cut slots or fail to de-burr and it is very easy to get a home made thread chaser cross threaded in the hole. It is a good idea with these home made chasers to run a proper sized nut onto the modified bolt several times using anti-seize before attempting to repair any damaged threads with it. Some people may scoff at doing this but I have done it many times and have had really good success with it, the trick is to be careful with the slots and to use a hard bolt and anti-seize.



To repair spark plug threads just go to almost any auto parts and buy a spark plug chaser, it will be double ended with both common thread sizes. This thing is probably no harder than a grade 8 bolt and will not cut threads but with a little anti-seize applied will easily repair most Aluminum head spark plug threads as well as most cast iron heads.

Yes, I agree definitely make sure those threads are good before using it. And personally I would spend some time trying to find a proper one before resorting to making my own. Like I said I was lucky and do some occasional work at a machine shop so was able to borrow one. The guys at the auto parts stores really had never heard of it - pretty sad really. Although I did take the borrowed chaser in to the store and he was interested in learning about it, which is something I guess.

[oldred]

Originally Posted by scrimshaw

The guys at the auto parts stores really had never heard of it - pretty sad really.

If you think finding a thread chaser is bad just try finding a starter (taper) tap. Everyone that sells taps/dies has plug style taps and most will also carry bottoming taps but if you ask for a starter tap 99% of the time they will try to sell you a plug tap, most will tell you it is a starter tap. Sure you can cut new threads with a plug tap, not even hard to do on thin stuff, but a taper tap is soooo, much easier to start new threads with and far less likely to break BUT just try to find one anywhere except a machine tool supply.

[jaguarxk120]

Go to Summit racing, type in "thread chaser" a complete list will come up ARP makes them. Better than a bolt with cut flutes, less than a tap. Used for cleaning threaded holes.

[jaguarxk120]

Red go on line to Wholesale Tool Co. they sell over the counter and have a full line of tooling. You can get the cheap off shore stuff for one time use or US made higher quallity tooling.

[metalmeltr]

sears sells a set of them under the craftsman name but the call it a rethreader set.
who else thinks that people that actually work at the store should read the catalog and pay atention to it?

[pittbull7934]

Originally Posted by metalmeltr

sears sells a set of them under the craftsman name but the call it a rethreader set.
who else thinks that people that actually work at the store should read the catalog and pay atention to it?

Went to Sears and got it, I think it is called the "rethreading kit" for mechanics.

49.99

the arp kit was 80 and only came with 4 pieces/

[jaguarxk120]

I listed the ARP kit because it was listed at Summit racing. Heck for $80 you can get a coupla of tap and die sets at HF, when they wear throw them out.

[heyjude076]

Originally Posted by jaguarxk120

I listed the ARP kit because it was listed at Summit racing. Heck for $80 you can get a coupla of tap and die sets at HF, when they wear throw them out.

Tap and die sets are not the same as threadchasers. Tap and dies are for cutting threads. As stated above:

Originally Posted by cucumber1949

My understanding is that a thread chaser will clean up the threads without cutting the material while a tap will remove material.