MAC rethreader dies

[coolmercury]

These were in a box lot I bought, sizes 1/4 to 3/4", 8 NF sizes.  I had not seen these before, are they uncommon.

[goodfellow]

Not that uncommon - I think most of the tool truck sets were rebranded Kastar Hand Tools products.

NF was used on a lot of British vehicles at one time

[ken w.]

 I have that same set with a different name.

[Matt_T]

Those rethreading dies are very common. Lots of mechanics will own a set.

NF/UNF are regular US fine threads. But nobody in the States calls them that. Here they're either "fine", "SAE", or specified by diameter and TPI.

[skfarmer]

I have similar sets. I think ki e are jawco.

[fatfillup]

Yep, I see lots of them.  Hard to sell as techs want the larger set with metric and sae in the blow molded case with male and female thread chasers

Wonderful tool to own. 

[coolmercury]

Never had any of them nor seen them, I just use a die out of one of my tap and die sets.

[goodfellow]

Never had any of them nor seen them, I just use a die out of one of my tap and die sets.

The idea behind thread chasers was to primarily clean threads and to reshape buggered threads. Dies will cut material from even new threads --

[bmwrd0]

I have the same set marked Snap-on. Also in metric. They work great for common sizes.

[fatfillup]

Also the socket size for the chaser is the same size as a corresponding nut.  ie  1/4 20 is 7/16

I always try to chase threads or use a thread file before running a dye or tap on.  Won't work every time but does often.