Confirm three details before buying BF support units
BF is the support-side unit, usually paired with a fixed-side unit such as BK, FK, or EK. The fixed side carries the axial location (its bearings and locking arrangement take the axial load) while the support side only provides radial support, so the two ends are machined differently and are not interchangeable.
Before ordering, confirm three points: support model and brand, screw end dimensions, and installation space.
- Support model and brand, such as BF12, BF15, or BF20; detail dimensions can differ between brands.
- Screw end journal, bearing seat length, and lock thread, which decide whether the support unit fits.
- Coupling end diameter, length, and installation space, which decide the final assembly position.
Read the model number correctly: a BF12 relates to the bearing bore and mounting dimensions, not to the screw diameter. The 12 is a bore-size class; the screw nominal diameter has to be confirmed separately, and both belong in the RFQ.
What to include in the RFQ
When asking suppliers for a quotation, include the following in one RFQ to reduce back-and-forth confirmation:
- Support unit model, brand, and quantity.
- Screw diameter and end machining requirements or drawing.
- Fixed-side and support-side combination.
- End machining items: journal, bearing seat length, lock thread, undercut, and whether the coupling end is a keyway or a threaded end.
- Whether matched end machining, inspection report, and export packing are needed.
For how the ends pair with the unit, see the BK/BF end machining guide and BK/BF support unit selection.
How to compare support unit suppliers
Do not compare unit price only. Confirm whether the supplier machines from the real unit or brand drawing, can provide matched end machining, can meet batch lead time, and offers export packing, then make a combined decision.
Three questions separate the options:
- Does the quotation already include turning the journal and cutting the lock thread? If end machining is billed separately, the total can overtake a higher unit price.
- What tolerance or inspection method applies to the bearing seat? This decides how tightly the bearing seats after assembly.
- What happens if the old part and the support unit do not match before production starts? A supplier that checks first reworks far less.
FAQ
Can I buy a BF support unit alone? Yes, but you still need to provide the screw end dimensions so the supplier can confirm the fit.
Do you supply BF support units to traders? Yes. Traders and distributors ordering BF support units get the same RFQ confirmation: model and brand, screw end journal, bearing seat length, lock thread, coupling end, and export packing. Bulk orders can be combined with matched ball screws or end machining.
Does BF12 mean the screw diameter is 12 mm? Not necessarily. BF12 usually relates to bearing bore and mounting dimensions, not the screw model. Confirm the end journal and lock thread as well.
How do I know the BF unit matches my existing ball screw? Measure the screw end journal, bearing seat length, and thread, then send the measurement together with the support model. If you have the old unit, a photo with dimensions is the fastest way.
Next step
Turn this guide into an RFQ
When the specification direction is clear, send the details below together with quantity, lead time, and packing requirements.
Include these details
- Support-unit model, end drawing, or old-part end photos.
- Bearing journal, shoulder, lock thread, keyway, and coupling-end dimensions.
- Overall length, thread length, quantity, inspection, and packing requirements.
Category
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