Mac hex bit

[gj67stang]

I found this bit in the back of a drawer.

What's it fit? It has a 5/16" hex shaft and is about 1.25" long.

Mac T40 bit

 

[billymade]

That may have come in a hand impact kit; you can also put them in 5/16" bit holders... like these from Apex:

http://www.garagejournal.com/forum/showthread.php?t=86010

Apex stuff is excellent; they cater to production environments in factories... .
http://www.coopertools.com/catalog_pdf/index.cfm?parent1=10&catlan=EN

 

[MattT]

It's probably just a socket driver bit. MAC used to use a set screw retainer on them so the groove is most likely for the screw.

 

[nato]

It's probably just a socket driver bit. MAC used to use a set screw retainer on them so the groove is most likely for the screw.

He is right....I have some older MAC 3/8" drive sae hex socket bits w/ the little hex set screw retainer. The bit bases on mine are the same as in yours' pictured. The screw threads into the groove to retain it into the driver socket

 

[mrholeshot]

It was for a bit socket as has been said. It was made back when MAC gave a **** about quality. If you decide you want to sell it. It won't last long

 

[JSBriggs]

Ive got a Mac T40 socket (missing the bit) for sale if you are interested.

-Jeff

 

[mrholeshot]

Here is the best way to explain that, lol