......does this all look right so far?
OK so final question. Ron earlier stated that the above snap on bits were thread chasers not taps, is this correct? However I spotted this tool on the same snap on website that claims to be a thread chaser
TR25B, Set, Thread Chaser, Internal, U.S.
So which do I need to buy?
Yes, you're using the gauge correctly....
Re the TR25B... that's a different style of internal thread chaser I've never seen before; I'm used to the kind, like the earlier Sears/Snapon set, that look like thread cutting taps but aren't. All I know is the earlier ones in this discussion work fine so you would be safe purchasing them. And I would observe that the TR25B set will be fussier to use since you will have to dismount/remount the "blade" for each different thread, rather than just select the right one and use it. And that for substantially more money you are getting only internal inch thread chasers, no external, and no metric.
Well this is interesting, from a tool-geek and terminology point of view: Snap-on classisfies the "tap-like" tool as a thread restorer, and the TR25B comb-like tools as thread chasers. So I guess that illustrates that there are two terms at work here: chasing, which I think means "following but not modifying" otherwise known as "cleaning", vs. "restoring" which I think means "reforming where necessary (but also cleaning)." That's an assumption I'm making given they carefully separate the two categories, I assume knowledgeably and on-purpose, and my guess that the "comb like" tool does not cut or re-roll the threads. But I don't know that that's true.
Right after I wrote that I tapped a 1/2" NPT hole completely crooked. I guess the skill comes and goes....
The instructions that came with my Sears rethreading taps and dies just said to use oil (eg motor oil). It's not a critical application, and you're not cutting, so you don't need thread cutting fluid.Didn't get a set in the end just bought 2 taps and 2 dies that I need for the moment. The price was pretty good £12.50 for all 4.
Cheers Keith appreciate the offer. I agree, going to try and only buy the tools I need rather than extra tools in sets etc that won't get used. Going to have a play with the tap & dies tomorrow night as I didn't get round to it today thanks to todays hangoverHi Trev, My way of thinking is only get taps and anything else you need but get quality ones that will last, Not cheap chinky gear nothing with the year of the cat stamped on it.
'Save your money for that chrome cleaner '
If there's something you might need but can't justify the cost let me know I may have it and you can always borrow it.