Threaded rod and tie bar RFQ checklist

What the supplier is actually delivering

Identify the item: fully threaded rod, double-end stud, upset-end tie bar, anchor rod, connector, or another drawing-defined component. List whether supply includes bar, heat treatment, finished threads, nuts, couplers, end plates, coating, and assembly. Assign the operations and inspections to the responsible parties so every bidder prices the same delivered item.

Describe the load path and interfaces at procurement level. Provide the drawing revision, joint or structure reference, stressed length, and unthreaded shank or reduced section. Identify thread engagement, coupler and nut arrangement, and bearing faces. Give field-adjustment range, installation constraints, and service environment. Include engineering requirements for cyclic, sustained, impact, low-temperature, or preload duty. A capacity calculation needs a clearly assigned responsible engineer and defined inputs. Do not request one from nominal bar diameter alone.

Identify the controlling drawing, project specification, material and thread standards, coating specification, and inspection plan. Agree how conflicts and deviations will be resolved. ISO 261 gives the general plan for ISO metric threads; ISO 965-1:2026 gives the tolerance system. The drawing still needs the actual thread designation, engagement, and joint requirements.

Sources:[1][2]

One control matrix for scope and cost

Ask each bidder to complete the same scope table. Check the differences that affect manufacture and price: bar versus finished component, cut or rolled threads, delivery heat treatment, mating hardware, coating, sacrificial test material, third-party inspection, and packing. Attach the drawing and relevant project clauses to the enquiry.

Do not combine alternative standards with a slash and leave the supplier to choose. A material designation, ISO 898-1 property class, custom project strength requirement, and coating designation answer different questions. For any allowed alternative, require a separate technical deviation showing product scope, dimensions, material, condition, mechanics, testing, thread, coating, documents, and qualification history.

Sources:[1][2][3][4][5][6]

Sources:[1][2][3]

Thread, hardware, and final condition

Treat thread geometry as an interface specification. Record nominal diameter and pitch, tolerance class, external and internal thread pairing, right- or left-hand direction, threaded length datum, runout and relief, incomplete-thread allowance, chamfer or point, end-face relation, and gauge basis. Distinguish total rolled or cut length from effective full thread. If two ends differ, call them out separately. For couplers or turnbuckle arrangements, identify adjustment direction and assembly position so two right-hand ends are not quoted where opposed threads are required.

Specify when acceptance occurs. ISO 965-1:2026 supplies a tolerance system for ISO general-purpose metric threads conforming to ISO 261; it doesn't prescribe whether the thread is cut or rolled. A thread can meet a tolerance class by either approved route, subject to material, geometry, process and drawing controls. State whether gauges apply before coating, after coating, or both, and whether the order controls pitch diameter, major diameter, functional size, surface, runout, and trial assembly. Coating allowance and mating-nut strategy must be resolved before tools are ordered.

Include mating hardware in the technical return even when another supplier provides it. Ask for nut or coupler standard, grade/property route, coating, tolerance, proof or project requirement, engagement, lubrication, locking, bearing faces, marking, and trial-fit plan. A long rod that passes a ring gauge may still fail the assembly requirement if the nut coating, thread allowance, engagement, straightness, or damaged first thread is uncontrolled. Define whether replacement hardware can be used across lots or must remain matched.

Sources:[1][2][4]

Material records and finished-product properties

ISO 898-1 defines mechanical and physical requirements for specified metric carbon- and alloy-steel bolts, screws, and studs within stated dimensional and test-condition limits. It doesn't necessarily cover every oversized, specially engineered, welded, field-tensioned, or structural tie-bar system, and it doesn't provide fatigue, corrosion, shear, weldability, or torque-clamp performance for every design. If it applies, name the edition, product, dimensions, property class, manufacturing restrictions, full-size or specimen tests, sampling, and additions. Otherwise use the controlling project/product specification.

Keep the identity chain through steel heat, cutting, heat treatment, thread manufacture, coating, hardware matching, testing, packing, and delivery. Each operation may create a new process lot. ISO 10474 covers inspection documents for ordered steel products, but the document type cannot choose finished-rod tests or certify the assembly. Ask for the actual heat chemistry, condition, treatment lot, required mechanical results, thread and dimensional results, coating records, report references, deviations, and the identity represented by each result.

Use ISO 3269 only within its acceptance-inspection purpose and scope. Purchaser acceptance sampling is not a substitute for manufacturing process control, qualification, lot traceability, or project-specific inspection on critical components. State the agreed inspection plan, sample or coverage, acceptance number, retest/resampling, sorting, concession, rejection, destructive-test allowance, third-party role, and final release. Resolve failed or missed tests before the lot is mixed, coated, or shipped.

Sources:[3][5][6]

Order wording that makes bids comparable

Complete the example with the approved material, thread, property, coating, and test requirements. Check that each selected standard covers the actual product and dimensions. Resolve open capacity, engagement, preload, fatigue, or installation-design questions with the responsible engineer before releasing manufacture.

Have bidders state the exact supply boundary, standard editions, and stock and finished dimensions. Identify the manufacturing sequence, responsible process teams, lot definitions, and mating hardware. Specify thread and coating allowances, final gauging, and mechanical and inspection coverage. Include traceability, destructive-test quantity, deviations, lead time, packing, and exclusions. Compare total released-assembly cost and qualification risk, alongside price per tonne or per rod.

Before order acknowledgment, reconcile the supplier's return with the drawing and purchase order. Confirm assembly scope, grade, dimensions, threads and mating parts, heat treatment, coating, final tests, lot identity, witness points, packing, and shipment release. List each accepted deviation with the approving person and document revision.

When the drawing, supply boundary, thread system, material route, quantity, inspection, and destination are settled, prepare the structured RFQ for quotation review.

Item: Double-end threaded tie bars for bracing assembly TB-214, drawing rev C
Quantity: [pieces] complete with [nuts / couplers / plates / washers]; supplier to state all exclusions
Geometry: Shank Ø[diameter] × overall length [datum and tolerance]; threaded zones and transitions per drawing; straightness [requirement/method]
Thread: ISO metric M[diameter] × [pitch], [tolerance class], [RH/LH] ends; effective full-thread length, runout/relief, end chamfer and final gauge condition per drawing
Material: [grade] to [controlling material/product standard and edition], [delivery condition]; alternatives only by written purchaser approval
Manufacturing route: [rolled / machined / supplier proposal subject to approval]; heat-treatment section, thread sequence, process teams and lot definitions to be returned
Finished requirement: [project/product requirement or applicable ISO 898-1 property class]; tests, specimen/full-size basis, lot/sample, acceptance and retest per order
Inspection: ISO 10474 [document type] with actual chemistry, condition, heat-treatment lot, required mechanics, thread/dimensional report, coating record and heat-to-finished-lot traceability
Protection: [system/designation/performance basis]; thread allowance and final gauging, lubricant/color, hydrogen-control/test route where applicable, repair and handling requirements
Assembly: Mating-part standards/grades/coatings, engagement, trial fit, match marking and replacement policy to be confirmed
Packing/marking/destination: Preserve heat/process/assembly identity; supported export packing; [city, country and delivery term]
Deviations/release: Clause-by-clause deviations and [purchaser/third-party] points resolved before production and shipment

Sources:[3][4][5][6]