Air Spring Conversion Kit, HiTorque Mini Mills 

Air Spring Conversion Kit, HiTorque Mini Mills
  • Better support for the mill head
  • Greater Z-axis travel with improved Z-axis upper limit
  • Includes gas strut and parts shown here
Part Number: 4005
Weight: 3.29 lb

Price: $79.95

In stock
Convert torsion spring HiTorque Mini Mills to air spring.

Mini mills use a torsion spring mounted on the side of the column to support the head. This air spring conversion kit for mini mills provides all the parts required to change to a vertical gas strut that mounts inside and above the column.

With the air spring and Z-axis limit installed, you can move the mill head up until the top of the casting is flush with the top of the column. You can move it down until it contacts the adjustable Z-axis stop set in its lowest position.

Besides all the parts required to mount the air spring, this air spring conversion kit for mini mills also includes a longer Z-axis rack so you can take advantage of the longer head motion.

This air spring has about 35 pounds of force. This about enough to support the head, and it is a heck of a lot more support than the torsion arm provides.

Chris Chris' Tips
This kit comes with complete instructions for installation.


This product works with the following mills. (If your machine is not on this list, we cannot verify compatibility.)

  •   BusyBee CX612 Craftex Mini Mill
  •   SIEG SX2 Mini Mill
  •   Micro-Mark 84630 MicroLux Mini Mill
  • 3900 HiTorque Mini Mill
  •   SIEG SX2L Mini Mill
  • 3960 HiTorque Mini Mill
  • 3990 HiTorque Mini Mill
  • 4190 HiTorque Mini Mill
  • 6450 HiTorque Mini Mill
  •   SIEG SX2LF Mini Mill