Thread chasers

[supton]

Wanted to clean out some threads earlier this weekend, did some reading, hadn't heard of "thread chasers" before but found a couple threads on it. What should I look for? Call me snobbish but I don't plan to leave my Toyota's too soon (might have a Honda before long), so I'm not too concerned about SAE. But I won't turn down SAE, who knows, maybe I'll get a kick for vintage iron, like when I was a kid.

This Kastar 971 seems about right. Is it? I'm not looking to go crazy, just want to chase out anything I might come across under the car.

I'm guessing a sparkplug chaser (would work on O2 sensors too?) would be good to have also?

 

[clinebarger]

That's a Lang kit....Decent quality in my opinion.

O2 sensors are 18mm while most modern spark plug threads are 14mm & 12mm is becoming more common, Ford used to use 18mm spark plugs quite often back in the day.

 

[spk2000]

Thread chaser down a spark plug hole might push something into the engine you wouldn't want in there. If it's messed up you might have to but basically they just clean debris out of the threads, Not quite a tap but one step back.

 

[bdcardinal]

ARP makes some really good ones. You can also get a bolt in the same size as the hole and cut grooves lengthwise down the threads.

 

[supton]

Originally Posted by bdcardinal
ARP makes some really good ones. You can also get a bolt in the same size as the hole and cut grooves lengthwise down the threads.

True, I could do that, just need a sacrificial bolt to do that.

I might just get that kit, seems like the need is creeping up on me--and of course, no one sells taps (let alone chasers) locally to me.

 

[Trav]

Originally Posted by bdcardinal
ARP makes some really good ones. You can also get a bolt in the same size as the hole and cut grooves lengthwise down the threads.


For chasers that's all I use, a hard bolt from Ace hardware with grooves cut in it. This works fantastic on brake line nuts too as it is hollow it does not touch the flared end inside like a bolt or chaser would.
The spark plug chasers commonly found in parts stores usually have a 14mm and 18mm end, the 18mm is for old Ford but it is the same thread as O2 sensor bungs and works great for cleaning them up.