Most circular knitting spare-parts quotations fail for a boring reason: the buyer and the supplier were not describing the same part. A needle, a sinker, a cam and a cylinder are not interchangeable line items, yet a two-line email asking for “prices for 500 needles” invites a reply that is impossible to accept, reject or compare. This RFQ template and specification checklist is built to close that gap before money changes hands.
Copy the fields below into your own document and delete what does not apply. The goal is not a long RFQ. The goal is an RFQ that forces the supplier to commit to machine fit, material, tolerance and traceability, so that a purchase order written against it means something. Where a value is needed, take it from the machine builder’s drawing or the approved component specification; do not fill in a number that nobody can trace back to a source.
Before drafting, it helps to standardise the part families with the circular knitting machine spare parts guide and to structure the receiving process with the needle and sinker incoming inspection guide. The RFQ is the front end of that same quality loop.
Why an RFQ needs more than a part number
A part number is only unique inside one company’s system. Across suppliers it can mean different revisions, different materials and different fits. When a machine is older, the installed part may already have been superseded, and the number on the store label may point to a revision that is no longer produced.
The RFQ therefore has to describe the part by function and by measurable attributes, and it has to state which machine it goes into. A needle that fits one cylinder diameter and gauge can be wrong for another machine of the same brand. Treat every field below as a question the supplier must answer, not as a formality.
Header fields: identify the machine and the part
| Field | Why it matters | Example of a weak answer |
|—|—|—|
| Machine brand and model | Determines fit and revision | “Standard circular machine” |
| Cylinder diameter | Sets the geometry around the machine | Omitted |
| Gauge (needles per inch) | Governs needle and sinker spacing | “Fine gauge” |
| Component position | Feeder, cam track, dial or cylinder slot | “Top” |
| Part number and revision | Ties to the drawing in use | Part number only, no revision |
| Drawing / sample reference | The controlling document | “Same as last time” |
If the supplier cannot confirm the revision against your drawing, the quotation is provisional by definition.
Needle specification fields
Needles carry the tightest dimensional requirement of the four families. Record the butt type, hook form, latch type, shank thickness and overall length, and reference the drawing that defines them. The working dimensions usually have to be held within a very small band — the standard tolerance on precision needles and sinkers is often quoted around ±0.005 mm — but that figure belongs to a specific part specification, not to every needle on the market. State the tolerance that applies to your part.
Also specify the intended operating conditions, because they change the requirement. Heat resistance, friction coefficient and coating all depend on the yarn and the running speed. If the machine knits abrasive or technical yarns, note that, because the needle selection described in the needles for technical textiles guide depends on the fibre as much as the gauge.
Sinker specification fields
Sinkers work as a system with the needle, the cam and the cylinder slot. On a cylinder-and-dial machine the sinker profile, thickness, butt position and edge condition all influence loop formation. Two sinkers that look similar can produce different fabric if the profile or the edge rounding differs.
Ask the supplier to state the sinker type, the profile reference, the material and the edge treatment. Groz-Beckert’s published material on sinker generations illustrates how much the geometry and the edge rounding matter to loop quality and service life. Specify the machine gauge the sinker is intended for, since a sinker that suits one gauge range will not suit another.
Cam specification fields
Cams are the wear-critical parts that guide needles and sinkers. The RFQ should identify the cam position (for example, knit, tuck, miss or transfer), the machine model and the track geometry. Material and hardening are the usual differentiators.
A cam can be made from a high-grade alloy tool steel such as Cr12MoV, hardened in a range that is commonly cited as HRC 58–62, but the exact specification depends on the cam’s function and the supplier’s process. Ask for the material grade, the hardening method and the target hardness, and request that the supplier confirm the coating or surface treatment if one is required. Do not accept “hardened steel” as a specification.
Cylinder specification fields
A cylinder is a high-value, high-consequence part. A replacement must match the trick depth, the slot profile, the number of needles and the gauge exactly, or the whole working system is compromised. The RFQ should state the diameter, gauge, needle count, trick dimensions and the surface treatment required.
Cylinders are frequently specified in a hardenable alloy steel, and a trick-depth tolerance on the order of ±0.01 mm is typical of a properly controlled specification — again, confirm the value against the machine builder’s drawing rather than a generic figure. Ask how the supplier verifies trick depth and slot straightness, and request the inspection method, because a cylinder cannot be judged by appearance.
Cross-family comparison
| Attribute | Needle | Sinker | Cam | Cylinder |
|—|—|—|—|—|
| Fit tolerance | Very tight | Very tight | Track and position | Slot / trick |
| Main wear driver | Yarn abrasion | Loop formation load | Needle and sinker contact | Needle movement, lubrication |
| Typical spec anchor | Drawing + material | Profile + edge | Material + hardness | Diameter, gauge, trick depth |
| Inspection focus | Geometry, latch | Profile, straightness | Hardness, track form | Trick depth, slot fit |
| Common RFQ omission | Butt type | Gauge range | Cam position | Needle count |
Material, coating and tolerance fields
For each part, require the supplier to answer three questions in writing: what material, what hardness or surface treatment, and what dimensional tolerance applies. Where a coating is involved, ask whether it is required for wear, friction or corrosion, and how it affects fit.
Tolerances must reference a drawing or a documented method. Ask which instrument and which feature will be measured. A quotation that promises “precise tolerance” without naming a value or a method cannot be checked at goods-in, which means the buyer is accepting the part on trust.
Quantity, packaging and lot traceability
Quantity should be quoted in the unit the factory actually uses, with the supplier’s minimum order quantity stated separately. If a blanket order is possible, ask for a release schedule and note the price-validity period.
Packaging matters for these parts. Needles and sinkers can be supplied in matched, parallel-positioned packages that reduce handling damage and mixing. Ask how the parts are packaged, how they are prevented from mixing during transport, and whether the lot code is on the outer and inner packaging.
Lot traceability is what makes a later defect investigation possible. Require a batch or lot identifier on the delivery documents and on the packaging, and ask the supplier how long records are retained. Without a lot code, a defective shipment becomes an untraceable stock problem.
Lead time and warranty fields
Split lead time into its parts: order confirmation, production, export preparation, transport and receiving inspection. Ask the supplier to state which event starts the clock and to give a normal and an expedited lead time. A single “30 days” figure hides the stage where delays actually happen.
Warranty terms should state the coverage period, what is excluded, and how a claim is handled — replacement, credit or investigation. For wear parts, ask whether the warranty covers material and manufacturing defects only, and how the supplier distinguishes a defect from normal wear.
Substitute approval fields
A substitute part is a decision, not a convenience. The RFQ should require the supplier to declare any deviation from the original specification and to propose the substitute for approval before shipment. Record the original part, the proposed substitute, the differences, the risk, the approver and any usage limitation such as a specific machine or a temporary period.
A supplier with a documented quality system such as ISO 9001 certification is easier to hold to this process than one without, and a CE declaration matters if the part is involved in a safety-related function, but neither removes the buyer’s obligation to approve the change.
Acceptance fields to attach to the order
- Part number, revision and machine fit confirmed.
- Material, hardness and coating as specified.
- Tolerance value and inspection method stated.
- Quantity, unit and MOQ recorded.
- Packaging and lot-code method agreed.
- Lead time with the trigger event defined.
- Warranty terms and claim route included.
- Substitute deviations declared and approved before shipment.
Attach these fields to the purchase order and to the goods-in record, so the same criteria are used from enquiry to receiving. For longer programmes, the planning side of the same exercise is covered in the spare-parts inventory optimization guide, and repeat consumption of a specific wear part can be planned with the sinker replacement schedule and cost guide.
FAQ
Can I just send a part number and ask for a price?
Only if the supplier and you share an up-to-date, revision-controlled catalogue. In practice, part numbers drift between suppliers, so the RFQ should also state machine fit, material and tolerance. A price without those fields is not comparable.
How do I compare quotations from two suppliers?
Force both into the same field structure: machine fit, material, tolerance, quantity, packaging, lead time, warranty and substitute policy. Then mark any field a supplier left blank, because those blanks are where the real difference usually sits.
Is a lower unit price always better?
No. A cheaper part that fails inspection or wears faster can cost more than the price difference. Compare landed cost together with defect rate, lead time and the supplier’s ability to support a claim.
Conclusion
A usable circular knitting spare-parts RFQ is a specification, not a shopping list. Insist on machine fit, drawing revision, material, tolerance, packaging and lot traceability for needles, sinkers, cams and cylinders, and require substitute deviations to be approved before shipment. The fields in this template turn a loose enquiry into a document you can inspect against, which is what makes the quoted price meaningful.
References
Manufacturer reference on needles, sinkers and system parts, useful for understanding how part families are specified by application.
Trade-press article describing how sinker material, edge rounding and dimensional stability affect loop quality and service life.
Official ISO page for the quality-management standard that underpins supplier documentation, traceability and nonconformance procedures.
Supplier-side discussion of how needle and sinker quality affects downtime and fabric quality in export production.
Technical overview of the cylinder, cam system, feeders and needles that helps a buyer describe component positions correctly.
Maintenance-oriented article on how needle, cam and cylinder condition interact and drive replacement decisions.