If you’ve ever submitted a request for quote on a custom spring and gotten back a price that didn’t match what you expected, or a lead time that seemed to come out of nowhere, the problem usually isn’t the supplier. It’s the RFQ.

Spring manufacturers can only quote what you tell them. A vague RFQ gets a vague quote, padded with assumptions to cover the supplier’s risk. A detailed RFQ gets a precise, defensible number, and a much better chance of an accurate lead time.

This guide walks through exactly what to include in a spring RFQ so you get a quote that reflects your actual part, not a guess.

Why Most Spring RFQs Get Inaccurate Quotes

Most spring manufacturers, including us, will quote a job even when information is missing. We have to. Engineers are on deadlines, and waiting on a fully detailed print before providing any number at all isn’t realistic in most cases.

But when a manufacturer fills in the gaps themselves, they fill them in conservatively. Unknown tolerances get padded. Unspecified materials default to whatever is easiest to source. Unclear quantities get quoted at low-volume pricing. Every assumption protects the supplier, not you.

The fix isn’t complicated. It’s specificity.

The Core Specifications Every Spring RFQ Needs

Spring Type — Start with the basics: compression, extension, torsion, or a custom wire form. This sounds obvious, but a surprising number of RFQs arrive without it clearly stated.

Material — Music wire, stainless steel (302, 316, 17-7 PH), chrome silicon, Inconel, and phosphor bronze all perform and cost differently. If you’re not sure, describe the operating environment and ask for a recommendation.

Dimensions — Wire diameter, outer/inner diameter, free length, total coils (plus leg length/angle for torsion springs). For wire forms, a dimensioned drawing is close to mandatory.

Load and Rate Requirements — Specify force at a given deflection, or spring rate directly. If you only know the application, describe the mechanical function clearly.

Tolerances — Tight tolerances cost more. Don’t default to the tightest tolerance “just to be safe” — it’s the fastest way to inflate a quote unnecessarily.

Quantity and Forecast — Share your initial order and your annual estimated usage. A one-time order of 500 prices very differently than 500 now with 50,000 forecasted annually.

The Specification Most Engineers Forget: Operating Environment

This causes more downstream problems than any other missing spec. Moisture, salt air, sustained or cyclic heat, vibration, galvanic exposure, UV — all of it drives material and finish decisions. Leave it out, and you risk a quote built on the wrong assumptions entirely.

Secondary Operations

Shot peening, passivation, plating, coating, grinding — specify these directly rather than assuming they’re implied. They affect both cost and lead time.

Certifications and Documentation

Material traceability, FAIR, PPAP, ITAR — state these upfront. They affect pricing and which suppliers can even take the job.

What to Do When You Don’t Have All the Information

Don’t guess or leave it blank. State what you know, what you don’t, and what you’re trying to achieve functionally. A manufacturer with real engineering support can help fill the gaps with you.

A Simple Way to Check Your RFQ Before You Submit It

Run through: spring type, material, dimensions, load/rate, tolerance, quantity/forecast, operating environment, secondary operations, certifications. Nine for nine gets you an accurate quote fast.