Timing Pulley RFQ and Procurement Checklist should be approached as a drive-system decision. The useful starting point is the mating belt and machine interface, followed by tooth count, working width, shaft mounting and duty conditions. This guide explains the checks that help an engineer or buyer turn timing pulley RFQ into an RFQ that can be verified against a catalogue row or drawing.
Identify the Drive Before Comparing Dimensions
For timing pulley RFQ, identify the complete belt marking before comparing pulley diameters. HTD is a curvilinear synchronous system and the nominal pitch must stay associated with its profile family. Record the driver and driven tooth counts when an existing ratio must be preserved. For a new drive, document the target speed ratio, driver speed and expected load before choosing tooth counts. This prevents a component-level decision from overriding the machine requirement.
For a replacement project, compare the measured value with the installed belt and machine arrangement before deciding that a catalogue row is equivalent. For a new project, document the design basis so later maintenance teams can understand why the pitch, tooth count and mounting style were selected.
Dimensions That Control the Installation
A pulley can match pitch and tooth count yet still fail to fit the machine because the bore, hub, flange or axial position differs. Measure the shaft interface, belt-face width, hub projection on both sides and the belt line relative to a stable machine datum. Where a taper bush is used, record both the pulley series and bush code. Where a finished bore is required, include fit, keyway and any retaining method on the drawing.
For a replacement project, compare the measured value with the installed belt and machine arrangement before deciding that a catalogue row is equivalent. For a new project, document the design basis so later maintenance teams can understand why the pitch, tooth count and mounting style were selected.
Operating Conditions That Belong in the Selection
The same nominal timing pulley RFQ component can see very different service depending on the machine. Starts per hour, reversing, shock loading, continuous operating time, temperature, contamination, cleaning and access for tensioning all influence the drive. A compact automation axis emphasizes repeatable motion and controlled alignment, while a conveyor or process machine may emphasize continuous duty and service access. Supply these conditions instead of asking the pulley to be selected from size alone.
For a replacement project, compare the measured value with the installed belt and machine arrangement before deciding that a catalogue row is equivalent. For a new project, document the design basis so later maintenance teams can understand why the pitch, tooth count and mounting style were selected.
Inspection Points Before Installation
Inspection should focus on dimensions that affect the drive: the shaft interface, axial location, tooth condition, face width and any drawing-controlled runout or datum relationship. A generic quality statement does not define acceptance. If a dimensional report, material document or order-specific record is required, identify it before production. During maintenance, watch for flange damage, edge wear, debris and signs that the pulley has moved on the shaft.
For a replacement project, compare the measured value with the installed belt and machine arrangement before deciding that a catalogue row is equivalent. For a new project, document the design basis so later maintenance teams can understand why the pitch, tooth count and mounting style were selected.
Open Questions to Close Before Ordering
What exact HTD profile and width is installed or specified?
What ratio or existing tooth count must be preserved?
What bore, fit, keyway or taper-bush arrangement is required?
How much hub projection and flange clearance is available?
What are the speed, load, starts, reversing and operating hours?
Which drawing, material or inspection records must accompany supply?
Commercial Planning Without Losing Technical Control
MOQ, samples, lead time and trade terms should be discussed after the product definition is clear enough to estimate the production route. Mixed-model orders can be consolidated, but each line still needs its own product code or drawing. Keep commercial negotiation from becoming a substitute for interface verification.
Record the conclusion in the RFQ or drawing so the same decision is visible to engineering, purchasing and inspection.
What to Send With the RFQ
Send profile, tooth count, belt width, shaft interface, hub/flange details, quantity, destination and a drawing or replacement measurement sketch. Add speed, ratio, load, center distance and environment for a new drive. Review the HTD product families, use the selection guide, or compare the relevant application notes.
Make Each Line Item Technically Complete
For mixed-model orders, list the full pulley identity, quantity and shaft interface on each line. Do not move all technical notes into one general paragraph that can become detached from the model it controls.
Keep measured values, catalogue references and project requirements clearly separated. If a required point is not stated in the relevant catalogue table or approved drawing, include it as an RFQ question or drawing requirement instead of filling the gap with a plausible but unverified value.
Commercial Terms Follow Technical Definition
Lead time, sample route and shipment term can only be confirmed cleanly after the product configuration, quantity and required documents are understood. Keep technical clarification ahead of final commercial release.
The purchasing record should keep a clear link between the machine requirement and the selected pulley. That means the complete belt or profile identity, tooth count, working width and shaft-interface information remain together with the product code. Any special material, finish, controlled tolerance, marking or report requirement should be stated separately so it cannot be mistaken for a universal feature of the whole family.
Procurement and Documentation
Once the selection is clear, keep the accepted product identity, quantity, destination and drawing revision on the same purchase line. Standard catalogue parts are normally planned around production-quantity minimums, while larger or higher-value items can be reviewed against the practical order value. Qualified new-client samples of 1–5 pieces may be reviewed at sample pricing when the configuration and manufacturing route are suitable.
Mixed-model orders can be consolidated toward a practical order value of about USD 1,500. Special materials and special processes follow the minimum quantity required by that process. Very small one- or two-piece requests are handled only as qualified engineering validation or paid-sample cases rather than retail replacement orders.
Lead time is confirmed after the technical definition is clear. Standard parts are typically planned at 10–25 business days, custom components at 20–45 business days, and project-based assemblies or related equipment at 45–120 business days where applicable. EXW, FOB, CIF and DAP are commonly supported; FCA, CFR, CPT, CIP and DDP can be discussed for suitable shipments. Treat these as planning ranges, not a shipment promise before order review.
A Practical Decision Sequence
Start with one complete technical order line tied to quantity and document needs. Keep the machine requirement separate from the catalogue choice: first identify what the drive must preserve, then compare only the rows or drawings that match that identity. This keeps a familiar-looking pulley from being accepted before its functional interfaces have been checked.
For an existing machine, preserve the original relationship before making changes. For a new design, record the target ratio, operating context and installation envelope so the RFQ release can be reviewed later without relying on memory or a photograph alone.
Build a Measurement Record
The most useful measurement set contains product family/code, tooth count, width, shaft interface, quantity, destination and documents. Mark which values were measured on the machine and which values came from a catalogue or released drawing. When a feature is inaccessible, photograph its relationship to a stable datum and identify it as confirmation-required rather than filling the gap with an assumed value.
Dimension drawings should be viewed at full readable width. Never scale a screenshot and then treat the scaled dimension as a measurement; use the printed value and the correct construction type.
One Failure Mode Worth Avoiding
A common error is separating technical inputs across messages so the quoted configuration becomes ambiguous. That can produce a part that appears close in the catalogue yet changes ratio, belt line, mounting or service access. Resolve the conflicting feature before requesting price so the quotation refers to one mechanically coherent configuration.
If two candidate configurations remain possible, send both the machine measurements and photographs and the preferred option. The quotation can then identify which interface still needs confirmation instead of silently converting uncertainty into a specification.
Turn the Technical Choice Into a Quote-Ready Line Item
State the HTD/profile family and complete belt information.
Provide the tooth count, working width and relevant dimension or drawing references.
Define the bore or bush, shaft data, hub projection and belt-line position where applicable.
Add quantity, destination, required documents and the drawing revision used for the request.
When one item above is genuinely unknown, label it for confirmation. A precise open question is more useful than a plausible value that was never measured.
Questions Buyers Commonly Ask
What should be confirmed first?
Confirm one complete technical order line tied to quantity and document needs. That prevents later dimensions from being compared across the wrong product family or installation route.
What information is most useful for a replacement?
Send product family/code, tooth count, width, shaft interface, quantity, destination and documents, plus clear photographs before the old pulley is removed. The photographs preserve axial orientation and neighboring clearances that a loose part cannot show.
When should a drawing be used?
Use a controlled drawing whenever the catalogue row does not completely define the shaft interface, hub/flange arrangement, finish, tolerance or inspection requirement that matters to the machine.
One Drawing Revision Should Control the Custom Interface
A quote-ready drawing separates the standard belt-side geometry from the features being customized. Show the HTD family, tooth count and working face, then dimension the shaft connection, hub projection and flange positions from clear datums. Material, finish, marking and inspection requirements should be listed only when they are controlled by the order.
Put the revision on both quotation and purchase order. If a machine design changes after the quote, issue a new revision rather than relying on an email sentence that can be separated from the drawing later.
Commercial Planning Starts After the Configuration Is Clear
Production MOQ, sample route and lead time depend on the selected model and manufacturing route. Standard catalogue parts are normally planned around production quantities. Qualified 1–5 piece samples may be reviewed at sample pricing where suitable, while mixed models can be consolidated toward approximately USD 1,500. Special materials and special processes follow their process minimums.
Typical planning ranges are 10–25 business days for standard parts and 20–45 business days for custom components after technical release. Shipment terms such as EXW, FOB, CIF and DAP can be discussed with the destination; FCA, CFR, CPT, CIP and DDP can be reviewed for suitable orders. Final commitments follow the released specification and quantity.
A Good RFQ Lets the Supplier Identify the Product Before Discussing Commercial Terms
Start the RFQ with product identity: HTD family, width series, tooth count, straight-bore or taper-bush route and the mating belt information. Then add the machine interface—shaft, bore/bush, hub/flange geometry and any controlled drawing. Quantity, destination and required documentation come after the technical identity so commercial planning is attached to the correct configuration.
For replacement work, include photographs and measurements before disassembly. For a new drive, add speed relationship, center distance, duty and environment. If a tolerance, material, finish or inspection record is mandatory, identify it directly instead of asking for a generic “certificate” that may not control the functional feature.
Mixed-model enquiries are easier to review when every model has its own line with quantity and configuration. Use the drawing revision or product code as the stable reference and avoid shorthand such as “same as previous” once widths, tooth counts or mounting routes begin to differ.
Build the RFQ So Technical and Commercial Decisions Stay on the Same Line Item
A useful RFQ allows the supplier to identify one mechanical configuration and one commercial quantity without searching through separate messages. For each pulley, state the belt/profile family, width series, tooth count, shaft interface and quantity. Add application notes and drawings where they affect selection, but avoid replacing measurable information with broad phrases such as “heavy duty” or “high precision.”
Commercial planning becomes meaningful only after the configuration is clear. A mixed-model order may combine several pulleys toward an overall order value, but each model still needs its own technical identity. Samples should also be identified as evaluation parts rather than treated as retail spares.
Profile/pitch, series width, teeth and exact product code when known.
Bore or bush, shaft size, keyway, hub/flange constraints and drawing revision.
Quantity per model, destination, requested trade term and target schedule.
State material, inspection or order-specific records only when they are required.
A concise RFQ with complete measurements is more useful than a long message with an ambiguous model. If one item is unknown, mark it clearly and provide the photo or machine measurement that can be used to resolve it during quotation.
