The M-3 T handle Variations

M-3 T handle. Notice the ball detent stops, and the style of the tips. With the logo, these change over time

The M-3 T handle existed from 1925 through the end.  There is no mention of any changes in the catalogs but there are several variations types that may help date your T handle. Theses are:

In the logos.
In the socket mount
In the knurled handle

9/16" Drive M-3 - T-Handle


9/16" Drive 9-32 M-3 Logos

The Logo changes can be seen

This photo shows the 3 logos
– The first one seems to go back to the start and through the mid 1930s
– The second one with smaller text seems to be from the mid 1930s to 1940
– The 3rd logo is the newest and ran from 1940 through the end.
It had been suggested that the in the mid 1930s, some have “Made in USA” in the latter period

Socket Mount

Late and early mount differences

Socket Mount
The ends are different too each has uniqueness.  

    • The oldest series has balls. It ran from the start to 1940. 
    • In 1940 the T-3 changed to a modern lip (socket stop to a collar) . This ran through 1945 and into the P series into the 1960s.
9/16" Drive 9-32 M-3 ends

Ball Detent and Knurl Handles

9/16" Drive M-3 Pinched Handle -vs ball detent

Early and Late handle differences
For the first series there are variations
There are 1, 2 and 3 ball versions
3 balls – this seems to be early – 1920s
2 balls – 1936 for sure, so mid 1930s
1 ball – late 1930s
There also are different location for the 2 ball version, 90 degrees, and 180 degrees. I have not seen enough tools to have this figured out yet
Knurled Handle
The handles have a knurled center piece. In nearly all have ball stops, but there is one example where the stops are pinched. It is unclear when this was done. It may be very early