Sample Request & RFQ Guide for Industrial Hose & Tubing

What Separates a Fast RFQ from a Slow One #

When buyers contact us after a sourcing delay, the pattern is almost always the same. The initial inquiry went out with a product description, a target price, and a delivery date. No dimensional drawing. No media specification. No pressure class. The supplier spent two weeks asking clarifying questions, the buyer spent two weeks answering them, and nothing shipped.

The specification gap is where most industrial hose RFQs lose time. This guide is structured around closing that gap before the first message goes out — not after.

The process from inquiry to first production order typically runs 6 to 14 weeks depending on hose type, assembly complexity, and whether tooling is involved. Knowing where the delays concentrate lets you compress that timeline meaningfully.

What Your Inquiry Must Specify — and What Suppliers Will Assume if You Don’t #

Before requesting samples or submitting an RFQ for industrial hose or tubing, seven parameters need to be locked. Not estimated. Not “TBD — will confirm later.”

1. Bore ID and OD
Specify in millimeters. Chinese suppliers work in metric. If your drawing is in inches, convert it and note both. For thermoplastic tubing, wall thickness matters as much as bore — a 12mm OD tube can carry three different wall thicknesses from the same extrusion line, each with a different pressure rating.

2. Working Pressure and Test Pressure
State the maximum working pressure (MWP) in bar or MPa, and the burst or proof test pressure you require. For hydraulic hose, the standard safety factor under SAE J517 is 4:1 burst-to-working. Some Chinese suppliers default to 2.5:1 unless you specify. That difference matters in a high-cycle system.

3. Media and Concentration
List the exact fluid, chemical, or gas the hose will carry. “Oil” is not enough — specify hydraulic fluid type (e.g., mineral oil, HFA, HFD), or for chemical hose, give the reagent name and concentration percentage. A supplier who does not receive this cannot select liner material correctly. We have seen NBR-lined hoses quoted for aromatic solvent service because the buyer wrote “chemical hose” without naming the chemical.

4. Temperature Range
Minimum operating temperature (cold start, outdoor storage in winter) and maximum continuous service temperature. These constrain the compound selection at the compounder level, not just the hose level.

5. End Fittings and Assembly Requirements
Specify whether you need bare hose or assembled hose. If assembled: fitting material (brass, carbon steel, 316 SS), thread standard (ISO 228 parallel, BSP, NPT, JIC, DIN), and ferrule type (crimped or reusable). Fitting dimensional data should come from your drawing, not from a verbal description. For fluid-control applications, the fitting interface is often where a leak originates — not the hose body.

6. Applicable Standards
If the hose must meet a specific standard, say so explicitly and link it to the requirement. Examples: hydraulic hose to SAE 100R2, food-grade hose to FDA 21 CFR 177.2600, chemical hose to EN 12115. A Chinese supplier who receives a standard reference without a documented requirement will generally default to the equivalent GB/T standard — which may carry wider tolerances on wall thickness and pressure retention.

7. Annual Volume Estimate
Include your estimated annual quantity even if it is rough. This affects whether a supplier will tool new mandrel sizes, which production run they slot your sample into, and whether they will negotiate on unit price. A buyer who writes “annual volume: unclear” gets treated as a spot inquiry regardless of their actual intent.

RFQ Template — Fields That Determine Quote Quality #

Below is the field structure we recommend for industrial hose RFQ submissions to Chinese suppliers. The comment column shows what happens if each field is left blank.

A completed RFQ against this template cuts back-and-forth by roughly half in our experience. The fields most commonly left blank by first-time buyers are temperature range and annual volume — and those two omissions together produce most of the specification errors we see at incoming inspection.

Sample Request — Quantities, Lead Times, and What to Actually Test #

How many samples to request

For straight hose (no fittings), request a minimum of 3 pieces at your specified length. This gives you one for dimensional verification, one for pressure testing, and one for chemical or media compatibility testing if required. For assembled hose with crimped fittings, request 5 pieces — enough to pull-test two fittings destructively while retaining three for functional review.

Do not request one sample. A single piece tells you nothing about lot consistency, and if it fails a test, you have nothing to retest against.

Typical sample lead times from Chinese suppliers

• Standard construction, stocked compound (e.g., NBR hydraulic hose, 6–25mm bore): 7–14 days from drawing approval
• Custom compound or non-standard bore: 21–35 days, depending on whether a new mandrel is required
• PTFE-lined or corrugated hose with custom fittings: 28–45 days
• Food-grade or pharmaceutical-grade silicone requiring batch-specific FDA or EU 10/2011 migration test documentation: add 10–15 days for lab testing

These are dispatch lead times from China. Add your transit time.

What to test when samples arrive

This is where we see the most skipped steps in buyer qualification programs. A visual check and a pressure hold test are not sufficient for hose qualification. Our incoming sample evaluation — tracked under what we call the HSQ-04 protocol — covers the following in order of diagnostic priority:

• Dimensional check: Bore ID, OD, wall thickness at minimum 3 cross-sections per piece. Tolerance per drawing, typically ±0.5mm on bore for hose up to 50mm ID.
• Hardness (Shore A): For rubber hose, verify compound hardness against COA specification. Acceptable variance: ±5 Shore A points. Wider variance signals compound substitution.
• Pressure retention test: Hold at 1.5× MWP for 60 seconds minimum with no leakage, fitting movement, or visible deformation. For hydraulic hose this is a baseline — some buyers specify 200% MWP for 30 seconds per their internal standard.
• Pull-off test (assembled hose only): Axial load to fitting pullout. Minimum threshold should be stated in your drawing — for DN12 hydraulic hose with standard crimp fittings, a 5,000N pullout load is a common internal minimum.
• Bend radius check: Confirm the hose achieves the minimum bend radius stated in the drawing without kinking, liner collapse, or cover splitting.
• COA cross-check: Compare compound lot number, hardness, and tensile strength on delivered COA against your approved sample COA. Any deviation in lot number triggers a hardness spot-test.

Chemical compatibility testing (immersion per ASTM D471) is done at the qualification stage, not on every sample shipment — but the first sample submission should include a supplier-issued chemical compatibility declaration for your specific media.

The Overlooked Variable: Tooling Ownership and Its Effect on Long-Term Supply #

Here is the factor that does not appear in most hose RFQ guides but changes the economics considerably: who owns the mandrel tooling.

For non-standard bore sizes (anything outside the common 6, 8, 10, 12, 16, 19, 25, 32, 38, 51mm sizes), the supplier will need to fabricate a new mandrel. Tooling cost for a single mandrel in China typically runs in the range of ¥800 to ¥3,500 depending on length and material. This is often absorbed into the first production order — or waived entirely on orders above a threshold volume — but the ownership of that tooling is rarely documented in the initial RFQ.

If the tooling stays with the supplier and you switch manufacturers, you pay tooling again. We have seen buyers discover this after a supplier quality failure forced them to re-source, at which point the tooling cost and 4–6 week re-tooling lead time became a significant barrier to switching.

The recommendation is straightforward: document tooling ownership in the purchase order, not just the RFQ. If you are paying NRE (non-recurring engineering) charges, the tooling should transfer to your ownership upon payment confirmation. Get this in writing before samples are approved.

For standard bore sizes sourced from pump-valve-seals and related fluid system component categories, this is less of a concern — standard tooling exists across dozens of suppliers and switching costs are low. For custom assemblies, it is the hidden variable that most single-source situations trace back to.

Implementation Notes — After the Sample Arrives #

Post-sample approval is where procurement teams lose the momentum they built during the RFQ stage. A few things to manage actively:

First, confirm the sample COA before approving. The COA should include compound lot number, Shore A hardness, tensile strength, elongation at break, and (for hydraulic hose) a pressure test certificate for the specific batch. A COA that lists only material designation without batch-level data is not sufficient for production approval. We have logged three cases in our Category B incident tracker where production deliveries deviated from approved samples due to compound lot changes that were not reflected on the production COA.

Second, lock the approved sample physically. Keep one piece from each approved sample set in your incoming inspection reference library. When production shipments arrive, your QC team needs a physical benchmark, not just a PDF.

Third, issue a supplier approval memo that references the sample lot number, test results, and the specific drawing revision. This protects you if a dispute arises over conformance later.

For incoming inspection of production hose, a standard AQL 2.5 sampling plan under ISO 2859-1 is a reasonable starting point for dimensional attributes. Pressure testing should be done on 100% of assembled hose for safety-critical applications, not on a sample basis.

Recommended milestone sequence after sample approval:
– Week 1–2: Issue approved sample memo, confirm production drawing revision, place trial order (typically 50–200 pieces or 100–500 meters depending on type)
– Week 3–6: Production and QC at supplier; request pre-shipment inspection report
– Week 7–9: Transit and incoming inspection
– Week 10: First production lot accepted or disposition decision made

Practical Guidance for Buyers #

When sourcing industrial hose from China, the first specification to lock is not tensile strength — it is bore ID with tolerance class and working pressure with safety factor. These two parameters determine which compounds and constructions are even eligible, and every other spec flows from them. Requesting a COA before samples is backwards; request the sample drawing first and confirm the supplier can hold your dimensional tolerance before anything else.

The specific risk to watch: a supplier who quotes a standard GB/T hose grade against your SAE or EN-specified requirement. The GB/T standard governing rubber hose wall thickness allows tolerances up to ±15% in some constructions, versus ±10% under equivalent SAE specifications. On a high-pressure assembly, that variance compounds with fitting crimp depth to produce inconsistent pull-off performance lot to lot. We have seen this failure mode appear not at sample approval, where one or two pieces were tested, but at the third or fourth production delivery, when a wider range of compound lots entered the supply chain.

Before committing to volume, insist on a minimum 3-lot COA review covering consecutive production batches. Each COA should show bore ID measurements, wall thickness, Shore A hardness, and batch-specific pressure test results. If a supplier cannot produce three consecutive batch COAs, their production consistency is unverified regardless of what their initial samples showed. This single qualification step, which adds roughly 4–6 weeks to the process, has saved multiple qualification rejections in the 6–12 month window after first delivery.

FAQ #

What is the minimum information needed to get a valid hose quote from a Chinese supplier?
Bore ID, OD, working pressure, media, temperature range, and end fitting type. Without all six, you will receive a conditional quote that will change after clarification — which typically adds 1–2 weeks to the process.

How long does sample delivery from China typically take?
For standard constructions, 7–14 days from drawing approval to dispatch. Custom bore sizes or specialty liners extend that to 21–45 days. Allow additional time for transit — typically 5–10 business days for air freight, 3–5 weeks for sea.

Should I request assembled hose samples or bare hose samples first?
It depends on your testing priorities. If fitting pull-off and leak performance are critical, request assembled samples from the start — testing bare hose then separately testing a fitting combination misses the crimp quality variable. If dimensional conformance of the hose body is the primary concern and you have your own fitting inventory, bare hose first is more efficient.

Can I negotiate NRE tooling costs for custom bore sizes?
Yes, and you should. Suppliers frequently waive tooling costs at order volumes above a defined threshold, or split the NRE over the first two purchase orders. The number to negotiate toward is zero NRE at your forecast volume — and the non-negotiable term is tooling ownership transferring to the buyer upon payment, regardless of whether costs were waived.

What is a realistic timeline from initial inquiry to first production order?
6 to 10 weeks for standard constructions with a complete initial specification. 10 to 16 weeks for custom assemblies requiring new tooling, specialty compounds, or third-party compliance testing (FDA, ATEX). The difference between the fast and slow end of each range is almost always how complete the inquiry was on day one.

What certification should I require with every production shipment, not just at qualification?
A batch-specific pressure test certificate and COA showing compound lot number and Shore A hardness. For food-grade or pharmaceutical hose, a batch-specific migration test report or a declaration of conformity against the relevant regulation (FDA 21 CFR 177.2600 or EU 10/2011) should accompany each shipment.

Is it necessary to visit the supplier before placing a first production order?
For commodity hose in standard constructions under 20 bar working pressure, a remote qualification based on samples and COA documentation is generally sufficient. For safety-critical applications above 100 bar, custom PTFE-lined assemblies, or hose destined for food, pharmaceutical, or ATEX environments, an on-site audit before first production order is worth the cost. The audit findings that matter most are compound traceability records and crimp machine calibration logs — not the cleanliness of the production floor.

Published by sinoraw.com Technical Team | Request a sourcing consultation