Right- and left-hand descriptions are part of the mating relationship, not decorative labels. A spiral bevel pair is designed so the two members mesh with the intended hand, ratio, shaft relationship and mounting position. When one of those items is recorded without a defined viewing convention, an RFQ can become ambiguous very quickly.
Record the hand of both members with a defined viewing direction
Photograph or sketch the gear and pinion from a known side and label the viewing direction. If the original drawing contains a hand designation, keep that wording with the drawing revision. For replacement work, show both members together before disassembly if possible.
The goal is not to teach the supplier a generic naming rule; it is to make your specific pair impossible to misread.
Hand is only one part of the pair definition
| Pair variable | Question to answer |
|---|---|
| Hand / spiral direction | How is each member designated and from which viewing direction? |
| Ratio / tooth counts | How many teeth are on the gear and pinion? |
| Shaft angle | What is the included angle between the two axes? |
| Mounting position | Which surfaces or axes locate each member in the housing? |
| Backlash | Is there a specified operating or assembly range? |
Rotation changes which tooth surfaces carry load
The active contact surface depends on the direction of rotation and which member drives. If the machine routinely reverses, state that in the application data. It can affect how the buyer wants the pair inspected or evaluated in the assembly.
Do not infer the direction of load from a single static photo. Describe the operating direction or provide an assembly sketch.
Replacement work needs the mating gear
A worn single gear may still reveal tooth count and hand, but it does not automatically reveal the complete original geometry. The mate, housing dimensions, legacy drawing or an unused reference part can provide information that wear has obscured. If only one member is being replaced, its relationship to the remaining gear must be reviewed before manufacturing.
What to send with the enquiry
Include clear orientation photos, both tooth counts, any original part number, the shaft angle, the mating component and the drawing or housing references used to set the gear position. Mark unknown items as unknown instead of assigning a hand or mounting value from appearance alone.
Common hand-identification mistakes
Three mistakes appear repeatedly in replacement enquiries. The first is labeling only one member without showing the mate. The second is calling a hand from an undefined viewing direction. The third is assuming that the direction of rotation automatically defines the hand. Keep those concepts separate: record the tooth orientation, show the viewing direction and then describe operating rotation as application information.
When several photos are supplied, mark one as the reference view and label the gear and pinion consistently. A simple annotation on the photo is often more useful than a long email description.
Questions buyers often ask
Can right- and left-hand gears be swapped?
Do not assume they can. The pair is designed around a specific tooth orientation and mating relationship. Review both members and the drawing before changing hand.
Does reversing rotation require a different gear pair?
Not automatically. Reversal changes which tooth surfaces carry load, so the operating cycle should be part of the application review.
What if the original hand marking is missing?
Use the physical pair, a defined viewing direction, clear photos and any legacy drawing to establish the orientation before the replacement drawing is approved.
Send the gear pair, drawing and duty in one RFQ.
The more clearly the mating relationship and assembly datums are defined, the faster the configuration can be reviewed.
Ordering & delivery guidance
MOQ is flexible by product type, manufacturing route and total order value. Suitable new projects may request 1–5 sample pieces at sample pricing. Mixed models can be combined when the order total reaches approximately USD 1,500. Orders of 1–2 pieces can be reviewed, although unit cost is normally higher.
Typical planning windows are 10–25 working days for standard parts, 20–45 working days for customized components and 45–120 working days for project-type equipment or assemblies. EXW, FOB, CIF and DAP are commonly supported; FCA, CFR, CPT, CIP and DDP can be discussed for the shipment.
