Buyer summary
What to prepare before an RFQ
- Document the full route and the tightest bend instead of reporting a bend-radius number without context.
- Separate static bends, installation bends and repeated movement around guides or sheaves.
- Provide construction, diameter, coating, housing, termination and clearance information together.
- Ask for project-specific confirmation when the drawing, equipment or supplier specification controls the minimum radius.
Common mistakes
Details that often cause RFQ rework
Measuring a loose cable radius without recording the installed route or hardware.
Using the same bend assumption for static routing and repeated movement.
Ignoring coating, housing, guide clearance or the fitting transition at the bend.
Approving a replacement from a photograph that hides the tightest bend or contact point.
Wire Rope Bend Radius for Cable Assemblies: How to Review the Route
Wire rope bend radius should be reviewed from the installed route, not from a generic number copied into an RFQ. Construction, diameter, tension, movement, guides, sheaves, coating, housing and end fittings all influence the applicable requirement. The buyer’s first job is to make the tightest part of the route visible and identify which field still needs supplier confirmation.
This guide is for OEM engineers, maintenance teams and sourcing buyers preparing a wire rope or routed control cable assembly request. It focuses on route evidence; it does not publish a universal ratio, load rating or service-life guarantee.
Static, installation and repeated movement are different
| Route condition | What to record | Review question |
|---|---|---|
| Mostly static bend | Fixed supports, anchor points and final position | Does the assembly remain within the equipment’s intended geometry? |
| Installation bend | Temporary path used to place the cable | Will the cable be damaged or kinked before the final route is established? |
| Repeated movement | Direction, cycle context, guide or sheave and tightest radius | Does the selected construction and hardware suit the moving route? |
| Housed or coated route | Housing, lining, coating and finished outside diameter | Is clearance controlled by the finished assembly? |
Do not use the same assumption for each condition. State which route the buyer is describing.
Repeated movement needs a different review from a static installation bend. Cyclic flexing can contribute to fatigue, but the outcome cannot be calculated from a generic ratio or the construction name alone. The selected rope, diameter, tension, route, contact surfaces, hardware and project-defined operating conditions all matter. This guide does not predict cycle life; provide the route and movement context for project-specific confirmation.
Show the tightest part of the route
A useful route pack includes a full layout view and a close-up of the smallest bend. Mark the cable direction, fixed housing points, sheaves, guides, clamps, brackets and nearby edges. Add the neutral and operating positions when the cable moves. If a fitting enters a slot or bracket, show the transition into the bend.
The Custom Wire Rope Assembly page and Wire Rope Assemblies category provide the commercial route. The correct construction and dimensions still need to be reviewed against the equipment and drawing.
Separate cable geometry from hardware clearance
The cable’s bend is only one part of the path. A housing, coating, end fitting, guide, pulley groove or mounting bracket may create the real clearance limit. Record:
- Bare cable diameter and finished outside diameter where relevant.
- Construction and material if known.
- Housing or casing length, support points and lining information.
- Guide, sheave, pulley, clamp and bracket geometry.
- End A and End B fitting shape, entry direction and transition length.
- Space available around the tightest bend and any adjacent edge.
For a routed control cable, compare the Bowden Cable Assembly and Push Pull Control Cable product paths only after the function, housing and movement are clear. A similar-looking cable can have a different route or terminal requirement.
Avoid ungrounded bend-radius values
If the drawing or equipment manual supplies a minimum radius, include the revision and reference. If the value is not known, provide the route evidence and ask the supplier to confirm the applicable requirement for the selected construction and diameter. Do not replace a missing project value with a generic ratio that may belong to another rope, coating or movement condition.
This is especially important when the cable crosses a sheave or moves repeatedly. The construction, diameter, tension and hardware can change the engineering review. The bend-radius question also does not answer the separate questions of load, safety factor, termination performance or service life.
Replacement and new-design RFQs
For a replacement, photograph the cable installed before removal when safe, then photograph the tightest route, both ends and the mating hardware. Note wear, flattening, broken wires, coating damage or changes made during maintenance. A used radius may show the old condition, not the intended new requirement.
For a prototype or new design, send the drawing or measured sketch, neutral and operating positions, route constraints, interface dimensions, material or coating requirements, quantity and any open design questions. Drawing-Based Cable Assembly and Sample-Based Cable Matching support the evidence handoff before Request a Quote.
Route review checklist
- Full route photo or drawing with cable direction marked.
- Tightest bend and reference method identified.
- Static, installation or repeated-movement condition stated.
- Construction, diameter, coating and housing fields separated.
- Guides, sheaves, clamps, brackets and nearby edges shown.
- End A and End B, mating hardware and transition geometry labeled.
- Neutral and operating positions recorded where applicable.
- Application, quantity, sample or drawing revision and open questions included.
Common mistakes
The most common mistake is measuring the loose cable while ignoring the machine route. Another is using a static bend assumption for a moving cable. A third is overlooking the coated or housed outside diameter at a guide. Keep the route, assembly fields and project stage together in the RFQ.
FAQ
What controls bend radius?
Construction, diameter, tension, movement, hardware, coating, housing and termination all matter. The final value should come from the applicable project or supplier review.
Can I use one generic ratio?
Not as a universal rule. A generic ratio may belong to a different construction or application. Show the route and request confirmation for the selected assembly.
Should I measure a loose cable?
Measure it as supporting evidence, but make the installed route primary. Guides, sheaves, clamps and fittings can change the actual path.
What belongs in the RFQ?
Include the route, tightest bend, movement condition, construction, diameter, coating or housing, both ends, application, quantity and any drawing or sample reference.