Comparing B5 vs B14 motor flanges starts with the mounting interface. In the SEW-EURODRIVE catalog example below, B5 has metric through bores and B14 has metric threaded holes. A matching power label does not confirm a matching flange.
For a replacement motor on an aluminum cutting machine, obtain the complete motor reference and dimensioned mounting drawing. Compare the proposed interface with the approved machine connection before accepting the offer.
Four mounting checks
- Identify the specified flange and actual motor option.
- Compare the complete dimensioned flange interface.
- Keep the shaft connection in the same review.
- Confirm the delivered assembly and replacement scope.
On this page
1. B5 vs B14 motor flanges: read the designation
The SEW-EURODRIVE AC motor catalog dated October 2014, section 6.4.7, describes its DR.. flange-mounted designs. It identifies B5 with metric through bores, B14 with metric threads and C-Face with inch threads.
The same catalog uses /FF for its specified B5 arrangement and /FT for its specified B14 arrangement. These are manufacturer catalog designations. Preserve the actual manufacturer’s full reference instead of copying an option suffix from another product.
This historical catalog establishes the distinction discussed here. Confirm current availability and the supplied dimensions with the manufacturer of the motor being offered.
Read the complete nameplate and order reference together. Include the mounting option in the supplier’s written offer so the intended design is visible before delivery.
A short description such as “flange motor” leaves the interface unresolved. Ask the supplier for the exact option and corresponding drawing, including any manufacturer-specific variation.
When an equipment bill of materials names an approved replacement, retain that reference. Have the equipment supplier review a proposed alternative against the machine connection.
2. Compare the complete mounting drawing
Place the existing approved interface drawing beside the proposed motor drawing. Identify each document’s part number, revision, units and viewing direction before comparing features.
Follow the flange’s locating feature, fastening pattern and axial mounting face through the drawings. Use the actual callouts rather than estimating a dimension from a photograph.
For each dimension, retain its tolerance and feature identity. A diameter in one drawing may refer to a locating feature; another diameter may identify the fastening pattern. Keep the labels attached to their values.
| Drawing field | Review question |
|---|---|
| Mounting designation | Does the complete offered option match the required interface? |
| Locating feature | Are its identity, dimensions and tolerances compatible with the mating part? |
| Fastening features | Are the hole type, pattern and associated callouts identified? |
| Axial connection | Does the proposed drawing preserve the required mounting relationship? |
Have the responsible mechanical reviewer resolve any difference. Record the approved comparison with the motor reference and machine drawing.
If a supplier offers an adapter, include its controlled drawing and assembly scope in that review. An adapter proposal is a change that needs approval; its presence does not by itself establish compatibility.
Do not infer fastener length, thread engagement or tightening requirements from the B5 or B14 label. Use the approved assembly documentation and applicable equipment instructions.
3. Review the shaft connection with the flange
A replacement review also needs the proposed shaft connection. Retain the shaft dimensions and the approved mating component reference in the purchasing package.
If the drive uses a key, identify its actual type and the associated shaft and hub requirements. Keep the motor’s shaft detail associated with the equipment’s connection drawing.
Our Woodruff key and parallel key comparison explains why the purchased key’s identity belongs in that review. It does not choose a key or authorize a new connection for an unidentified motor.
Check the delivered shaft option against the quoted motor reference. Ask the supplier to identify any difference from the approved equipment specification before the order is released.
Keep the flange interface and shaft interface as separate review items on the same assembly. Confirming one does not close an unresolved requirement in the other.
Preserve the equipment context
Give the replacement supplier the machine model, relevant assembly identification and approved motor reference. Add clear images of accessible identification plates when available.
Have the responsible team define any inspection or service work under the machine’s applicable procedure. This purchasing guide gives no removal, installation or running-machine inspection steps.
4. Confirm the delivered assembly and replacement scope
List what the motor quotation includes. Identify the motor, mounting option, accessories and any separately supplied mating or adapter parts by their actual references.
Distinguish a motor-only supply from an approved assembled replacement. Identify who confirms the connection and who performs the authorized installation.
Keep electrical and operating requirements with the mechanical comparison. The flange designation does not describe every requirement on the equipment’s motor specification.
Our motor service factor guide reviews a different nameplate entry. Preserve that entry in context when comparing an alternative; it does not establish interchangeable mounting dimensions.
Ask the supplier to make exceptions explicit in the offer. A statement that a motor is “equivalent” should be accompanied by the actual reference and a reviewed comparison.
Save the confirmed offer and approved drawing package together. When the item arrives, keep its identification traceable to the motor and options that were ordered.
A fictional offer matches power but changes the holes
Imagine machine assembly F29 has an approved motor with a B5 flange reference. A replacement offer lists the same output power but identifies a B14 mounting option.
The power match leaves a mounting difference unresolved. Ask for the dimensioned proposed interface and the equipment supplier’s review of the complete connection.
Please confirm the full motor reference and mounting option for assembly F29. Our approved record identifies B5; your offer identifies B14. Provide the corresponding dimensioned flange and shaft drawing, identify any adapter or other connection change, and state what is included in the reviewed replacement.
F29 is an original fictional purchasing example. It contains no actual flange dimensions, accepted substitution or installation recommendation.
If an alternative is approved, retain the new references and affected drawing revisions. If it is declined, correct the quotation to the approved motor specification before confirmation.
Prepare a clear replacement RFQ
Send the full existing motor reference, approved mounting information and equipment assembly identity. Ask the supplier to mark every proposed change and provide its dimensioned product drawing.
Keep the reviewer’s decision with the final order. Record any approved adapter or accessory as an identifiable supply item rather than leaving it inside a general equivalence statement.
For a new cutting-machine inquiry, send JiurunCut the aluminum section, stock condition, cut lengths and quantities. Discuss the machine configuration through its confirmed proposal and technical information.
Send JiurunCut your cutting requirements or equipment inquiry. When comparing B5 vs B14 motor flanges, retain the exact motor reference and approved mounting interface.
Does matching power confirm a matching flange?
Compare the mounting drawings and complete offered references. Power is a different specification field.
Can a photograph replace the interface drawing?
Use an image to locate or identify the assembly. Retain the controlled dimensions and tolerances from the applicable drawing.