The Emco 120 family has several options for workholding.

The standard 120 came with the following,

  • manual 3 jaw chuck Ø80mm, Ø85mm
Original manual chucks are front mounted with bolts near the center and have a Ø70mm recess. Any front mounted chuck can be installed if an adapter plate is used. Chucks larger than Ø85mm can interefere with long boring bars and drills.
  • manual front mount 5C collet chuck, lever action
  • manual collet closer according to DIN 6343 136E-F20 (?)

While the 120P and 220P include a pnuematic drawbar actuator and had these work holding options,

  • Rohm KFD 85 power chuck and actuator (supplied standard)
    Autogrip picture

    Autogrip 3P-03

The actuator is the same for the chuck or the collet closer with the only difference being the drawbar to suit the chuck pull stud.
The original chuck is still avaliable direct from the manufacturer (Rohm) at a cost though, several thousand dollars.
Here is the link to Rohm where you can find the KFD85
I have found an alternative that is near on a direct fit and is within the reach of the hobbyist retrofitting thease machines, This alternative is manufactured by Autigrip who has a very reputable name within industry. The model number is 3P-03. unfortunatley the only jaws that I know of on the market for this chuck are soft jaws manufactured from Aluminium or steel.
Be aware though the drawbar pull force on this chuck is only rated at 4.5KN maximum and the original Rohm chuck is rated at 7KN maximum. There is an easy solution to sort this out, That is running the air supply to the actuator cylinder at a maximum of 75PSI. With the 110mm dia piston and 75PSI air the force exerted will be 4.6KN which is within range for the Autogrip chuck.
Here is the link to Autogrip where you can find the 3P-03
I would imagine that having both the collet closer and chuck option on a hobby machine would be far more benificial than one or the other in order to open up more solutions for work holding.
  • Rohm KFD 95 power chuck (optional 220 / 320)
  • Rohm 5C collet closer and actuator
  • Rohm KZF 20/2 Collet Chuck according to DIN 6343 140E-F22

Some power workholding options are incompatible with older machines equipped with the smaller spindle. KFD 95, 5C chuck, and the KZF collet chuck will not fit spindles lacking the Ø42mm counter bore. A longer type of 5C chuck was available for Compact 6P, but is not common.