FK / FF Series – Flange Type Ball Screw Support Unit

The FK/FF series is our ball screw support unit featuring flange-type mounting design, with FK as fixed end and FF as supported end. This series is designed for complete assembly interchangeability with equivalent series from brands such as HIWIN, THK, and PMI. Default configuration uses economical deep groove ball bearings, with angular contact ball bearings available upon request. Offered in C5 and C7 accuracy grades, suitable for industrial equipment requiring external mounting through the housing or space-constrained installations.

Key Features

  • Assembly Replacement – Direct replacement of existing same-series assemblies (fixed end + supported end) in customer equipment
  • Flange Design – Circular flange structure with 4-bolt mounting; can be secured externally through the equipment housing for greater installation flexibility
  • Flexible Bearing Options – Default deep groove ball bearings; optional angular contact ball bearings
  • Dual Accuracy Grades – C7 for general transmission; C5 for precision positioning; flexible cost-performance ratio
  • Moderate Size Range – Fits screw shaft diameters from 5mm to 30mm, balancing small and medium equipment needs
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Full Specifications

FK / FF Series – Flange Type Ball Screw Support Unit Specifications FK / FF Series – Flange Type Ball Screw Support Unit Specifications

© RFU Motion. Specifications subject to change without notice.

For the latest specs, please contact us.

Custom Manufacturing Available

Standard ball screws and linear guides don't always fit your design. Here's what RFU MOTION can customize based on your drawings:

  • Shaft end machining — machined precisely to your drawing
  • Screw length — cut to your exact requirement
  • Preload — light, medium, heavy, or custom value
  • Nut type — standard flange, special shape, or non-standard mounting interface
  • Rail length — continuous cutting with end finishing (chamfer or grinding)
  • Mounting holes — special thread sizes, hole spacing, or countersunk dimensions

Send us your drawing or specs — we'll deliver exactly what you need.

📦 MOQ: 1 piece / 1 set

⏱️ Lead time: Standard custom 5-7 days | Complex custom 7-15 days | Wire cutting +2 days

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